Merge "Unit test for Apex engine"

34 files changed, 3715 insertions, 71 deletions

diff --git a/core/core-engine/pom.xml b/core/core-engine/pom.xml
index f527d46c1..6e21cd444 100644
--- a/core/core-engine/pom.xml
+++ b/core/core-engine/pom.xml
@@ -51,9 +51,19 @@
             <version>${project.version}</version>
         </dependency>
         <dependency>
+            <groupId>org.onap.policy.apex-pdp.core</groupId>
+            <artifactId>core-infrastructure</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-all</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <profiles>
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/context/ApexInternalContext.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/context/ApexInternalContext.java
index f73281ada..8eb92a0f8 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/context/ApexInternalContext.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/context/ApexInternalContext.java
@@ -51,7 +51,7 @@ import org.onap.policy.apex.model.utilities.comparison.KeyedMapDifference;
  *
  * @author Liam Fallon
  */
-public final class ApexInternalContext implements AxConceptGetter<ContextAlbum> {
+public class ApexInternalContext implements AxConceptGetter<ContextAlbum> {
     // The key of the currently running Apex model
     private AxArtifactKey key;
 
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
index efd6aec5e..b703506ea 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImpl.java
@@ -33,7 +33,9 @@ import org.onap.policy.apex.core.engine.engine.ApexEngine;
 import org.onap.policy.apex.core.engine.engine.EnEventListener;
 import org.onap.policy.apex.core.engine.event.EnEvent;
 import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.core.infrastructure.threading.ThreadUtilities;
 import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexRuntimeException;
 import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
 import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
 import org.onap.policy.apex.model.enginemodel.concepts.AxEngineModel;
@@ -201,30 +203,37 @@ public class ApexEngineImpl implements ApexEngine {
     public void stop() throws ApexException {
         LOGGER.entry("stop()->" + key);
 
+        // Check if the engine is already stopped
+        if (state == AxEngineState.STOPPED) {
+            throw new ApexException(
+                            STOP + key.getId() + "," + state + ", cannot stop engine, engine is already stopped");
+        }
+
         // Stop the engine if it is in state READY, if it is in state EXECUTING, wait for execution to finish
         for (int increment = ApexEngineConstants.STOP_EXECUTION_WAIT_TIMEOUT;
-                        increment > 0;
-                        increment = ApexEngineConstants.STOP_EXECUTION_WAIT_TIMEOUT) {
+                        increment > 0; increment -= ApexEngineConstants.APEX_ENGINE_STOP_EXECUTION_WAIT_INCREMENT) {
+            ThreadUtilities.sleep(ApexEngineConstants.APEX_ENGINE_STOP_EXECUTION_WAIT_INCREMENT);
+            
             synchronized (state) {
                 switch (state) {
-                    // Already stopped
-                    case STOPPED:
-
-                        throw new ApexException(STOP + key.getId() + "," + state
-                                        + ", cannot stop engine, engine is already stopped");
-                        // The normal case, the engine wasn't doing anything or it was executing
+                    // Engine is OK to stop or has been stopped on return of an event
                     case READY:
-                    case STOPPING:
-
+                    case STOPPED:
                         state = AxEngineState.STOPPED;
                         stateMachineHandler.stop();
                         engineStats.engineStop();
                         LOGGER.exit("stop()" + key);
                         return;
+
                     // Engine is executing a policy, wait for it to stop
                     case EXECUTING:
                         state = AxEngineState.STOPPING;
                         break;
+
+                    // Wait for the engine to stop
+                    case STOPPING:
+                        break;
+
                     default:
                         throw new ApexException(STOP + key.getId() + "," + state
                                         + ", cannot stop engine, engine is in an undefined state");
@@ -232,7 +241,12 @@ public class ApexEngineImpl implements ApexEngine {
             }
         }
 
-        throw new ApexException(STOP + key.getId() + "," + state + ", cannot stop engine, engine stop timed out");
+        // Force the engine to STOPPED state
+        synchronized (state) {
+            state = AxEngineState.STOPPED;
+        }
+        
+        throw new ApexException(STOP + key.getId() + "," + state + ", error stopping engine, engine stop timed out");
     }
 
     /*
@@ -336,9 +350,11 @@ public class ApexEngineImpl implements ApexEngine {
             ret = false;
         }
         synchronized (state) {
-            // Only go to READY if we are still in state EXECUTING, we could be in state STOPPING
+            // Only go to READY if we are still in state EXECUTING, we go to state STOPPED if we were STOPPING
             if (state == AxEngineState.EXECUTING) {
                 state = AxEngineState.READY;
+            } else if (state == AxEngineState.STOPPING) {
+                state = AxEngineState.STOPPED;
             }
         }
         return ret;
@@ -352,6 +368,18 @@ public class ApexEngineImpl implements ApexEngine {
      */
     @Override
     public void addEventListener(final String listenerName, final EnEventListener listener) {
+        if (listenerName == null) {
+            String message = "addEventListener()<-" + key.getId() + "," + state + ", listenerName is null";
+            LOGGER.warn(message);
+            throw new ApexRuntimeException(message);
+        }
+
+        if (listener == null) {
+            String message = "addEventListener()<-" + key.getId() + "," + state + ", listener is null";
+            LOGGER.warn(message);
+            throw new ApexRuntimeException(message);
+        }
+
         eventListeners.put(listenerName, listener);
     }
 
@@ -362,6 +390,12 @@ public class ApexEngineImpl implements ApexEngine {
      */
     @Override
     public void removeEventListener(final String listenerName) {
+        if (listenerName == null) {
+            String message = "removeEventListener()<-" + key.getId() + "," + state + ", listenerName is null";
+            LOGGER.warn(message);
+            throw new ApexRuntimeException(message);
+        }
+
         eventListeners.remove(listenerName);
     }
 
@@ -411,7 +445,7 @@ public class ApexEngineImpl implements ApexEngine {
         if (internalContext == null) {
             return currentContext;
         }
-        
+
         for (final Entry<AxArtifactKey, ContextAlbum> contextAlbumEntry : internalContext.getContextAlbums()
                         .entrySet()) {
             currentContext.put(contextAlbumEntry.getKey(), contextAlbumEntry.getValue());
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/ExecutorFactory.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/ExecutorFactory.java
index f092ce716..fb6c7b45e 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/ExecutorFactory.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/ExecutorFactory.java
@@ -32,7 +32,7 @@ import org.onap.policy.apex.model.policymodel.concepts.AxTask;
  * @author Liam Fallon
  */
 
-public abstract class ExecutorFactory {
+public interface ExecutorFactory {
     /**
      * Get an executor for task selection logic.
      *
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutor.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutor.java
index 1c225f7b8..c30bda1b9 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutor.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutor.java
@@ -101,7 +101,8 @@ public abstract class StateFinalizerExecutor
     public void prepare() throws StateMachineException {
         LOGGER.debug("prepare:" + finalizerLogic.getId() + "," + finalizerLogic.getLogicFlavour() + ","
                         + finalizerLogic.getLogic());
-        argumentOfClassNotNull(finalizerLogic.getLogic(), StateMachineException.class, "task logic cannot be null.");
+        argumentOfClassNotNull(finalizerLogic.getLogic(), StateMachineException.class,
+                        "state finalizer logic cannot be null.");
     }
 
     /*
@@ -237,7 +238,11 @@ public abstract class StateFinalizerExecutor
      */
     @Override
     public String getOutgoing() {
-        return executionContext.getSelectedStateOutputName();
+        if (executionContext != null) {
+            return executionContext.getSelectedStateOutputName();
+        } else {
+            return null;
+        }
     }
 
     /*
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
index 97d51bf78..34ba3942c 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutor.java
@@ -146,11 +146,8 @@ public class StateMachineExecutor implements Executor<EnEvent, EnEvent, AxPolicy
         StateOutput stateOutput = new StateOutput(new AxStateOutput(firstExecutor.getSubject().getKey(),
                 incomingEvent.getKey(), firstExecutor.getSubject().getKey()), incomingEvent);
         while (true) {
-            // Execute the state
+            // Execute the state, it returns an output or throws an exception
             stateOutput = stateExecutor.execute(executionId, stateOutput.getOutputEvent());
-            if (stateOutput == null) {
-                throw new StateMachineException("state execution failed, invalid state output returned");
-            }
 
             // Use the next state of the state output to find if all the states have executed
             if (stateOutput.getNextState().equals(AxReferenceKey.getNullKey())) {
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/TaskExecutor.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/TaskExecutor.java
index 2a62f3ae2..c55d4924d 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/TaskExecutor.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/TaskExecutor.java
@@ -41,14 +41,14 @@ import org.slf4j.ext.XLogger;
 import org.slf4j.ext.XLoggerFactory;
 
 /**
- * This abstract class executes a task in a state of an Apex policy and is specialized by classes
- * that implement execution of task logic.
+ * This abstract class executes a task in a state of an Apex policy and is specialized by classes that implement
+ * execution of task logic.
  *
  * @author Sven van der Meer (sven.van.der.meer@ericsson.com)
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
 public abstract class TaskExecutor
-        implements Executor<Map<String, Object>, Map<String, Object>, AxTask, ApexInternalContext> {
+                implements Executor<Map<String, Object>, Map<String, Object>, AxTask, ApexInternalContext> {
     // Logger for this class
     private static final XLogger LOGGER = XLoggerFactory.getXLogger(TaskExecutor.class);
 
@@ -86,7 +86,7 @@ public abstract class TaskExecutor
      */
     @Override
     public void setContext(final Executor<?, ?, ?, ?> newParent, final AxTask newAxTask,
-            final ApexInternalContext newInternalContext) {
+                    final ApexInternalContext newInternalContext) {
         this.parent = newParent;
         this.axTask = newAxTask;
         this.internalContext = newInternalContext;
@@ -100,7 +100,7 @@ public abstract class TaskExecutor
     @Override
     public void prepare() throws StateMachineException {
         LOGGER.debug("prepare:" + axTask.getKey().getId() + "," + axTask.getTaskLogic().getLogicFlavour() + ","
-                + axTask.getTaskLogic().getLogic());
+                        + axTask.getTaskLogic().getLogic());
         argumentOfClassNotNull(axTask.getTaskLogic().getLogic(), StateMachineException.class,
                         "task logic cannot be null.");
     }
@@ -108,43 +108,43 @@ public abstract class TaskExecutor
     /*
      * (non-Javadoc)
      *
-     * @see org.onap.policy.apex.core.engine.executor.Executor#execute(java.lang.long,
-     * java.lang.Object)
+     * @see org.onap.policy.apex.core.engine.executor.Executor#execute(java.lang.long, java.lang.Object)
      */
     @Override
     public Map<String, Object> execute(final long executionId, final Map<String, Object> newIncomingFields)
-            throws StateMachineException, ContextException {
+                    throws StateMachineException, ContextException {
         throw new StateMachineException(
-                "execute() not implemented on abstract TaskExecutor class, only on its subclasses");
+                        "execute() not implemented on abstract TaskExecutor class, only on its subclasses");
     }
 
     /*
      * (non-Javadoc)
      *
-     * @see org.onap.policy.apex.core.engine.executor.Executor#executePre(java.lang.long,
-     * java.lang.Object)
+     * @see org.onap.policy.apex.core.engine.executor.Executor#executePre(java.lang.long, java.lang.Object)
      */
     @Override
     public final void executePre(final long executionId, final Map<String, Object> newIncomingFields)
-            throws StateMachineException, ContextException {
+                    throws StateMachineException, ContextException {
         LOGGER.debug("execute-pre:" + getSubject().getTaskLogic().getLogicFlavour() + ","
-                + getSubject().getKey().getId() + "," + getSubject().getTaskLogic().getLogic());
+                        + getSubject().getKey().getId() + "," + getSubject().getTaskLogic().getLogic());
 
         // Check that the incoming event has all the input fields for this state
         final Set<String> missingTaskInputFields = new TreeSet<>(axTask.getInputFields().keySet());
         missingTaskInputFields.removeAll(newIncomingFields.keySet());
 
         // Remove fields from the set that are optional
+        final Set<String> optionalFields = new TreeSet<>();
         for (final Iterator<String> missingFieldIterator = missingTaskInputFields.iterator(); missingFieldIterator
-                .hasNext();) {
+                        .hasNext();) {
             final String missingField = missingFieldIterator.next();
             if (axTask.getInputFields().get(missingField).getOptional()) {
-                missingTaskInputFields.remove(missingField);
+                optionalFields.add(missingField);
             }
         }
+        missingTaskInputFields.removeAll(optionalFields);
         if (!missingTaskInputFields.isEmpty()) {
             throw new StateMachineException("task input fields \"" + missingTaskInputFields
-                    + "\" are missing for task \"" + axTask.getKey().getId() + "\"");
+                            + "\" are missing for task \"" + axTask.getKey().getId() + "\"");
         }
 
         // Record the incoming fields
@@ -157,8 +157,8 @@ public abstract class TaskExecutor
         }
 
         // Get task context object
-        executionContext =
-                new TaskExecutionContext(this, executionId, getSubject(), getIncoming(), getOutgoing(), getContext());
+        executionContext = new TaskExecutionContext(this, executionId, getSubject(), getIncoming(), getOutgoing(),
+                        getContext());
     }
 
     /*
@@ -170,7 +170,7 @@ public abstract class TaskExecutor
     public final void executePost(final boolean returnValue) throws StateMachineException, ContextException {
         if (!returnValue) {
             String errorMessage = "execute-post: task logic execution failure on task \"" + axTask.getKey().getName()
-                    + "\" in model " + internalContext.getKey().getId();
+                            + "\" in model " + internalContext.getKey().getId();
             if (executionContext.getMessage() != null) {
                 errorMessage += ", user message: " + executionContext.getMessage();
             }
@@ -191,16 +191,19 @@ public abstract class TaskExecutor
         missingTaskOutputFields.removeAll(outgoingFields.keySet());
 
         // Remove fields from the set that are optional
+        final Set<String> optionalOrCopiedFields = new TreeSet<>();
         for (final Iterator<String> missingFieldIterator = missingTaskOutputFields.iterator(); missingFieldIterator
-                .hasNext();) {
+                        .hasNext();) {
             final String missingField = missingFieldIterator.next();
-            if (axTask.getInputFields().get(missingField).getOptional()) {
-                missingTaskOutputFields.remove(missingField);
+            if (axTask.getInputFields().containsKey(missingField)
+                            || axTask.getOutputFields().get(missingField).getOptional()) {
+                optionalOrCopiedFields.add(missingField);
             }
         }
+        missingTaskOutputFields.removeAll(optionalOrCopiedFields);
         if (!missingTaskOutputFields.isEmpty()) {
             throw new StateMachineException("task output fields \"" + missingTaskOutputFields
-                    + "\" are missing for task \"" + axTask.getKey().getId() + "\"");
+                            + "\" are missing for task \"" + axTask.getKey().getId() + "\"");
         }
 
         // Finally, check that the outgoing field map don't have any extra fields, if present, raise
@@ -210,7 +213,7 @@ public abstract class TaskExecutor
         extraTaskOutputFields.removeAll(axTask.getOutputFields().keySet());
         if (!extraTaskOutputFields.isEmpty()) {
             throw new StateMachineException("task output fields \"" + extraTaskOutputFields
-                    + "\" are unwanted for task \"" + axTask.getKey().getId() + "\"");
+                            + "\" are unwanted for task \"" + axTask.getKey().getId() + "\"");
         }
 
         String message = "execute-post:" + axTask.getKey().getId() + ", returning fields " + outgoingFields.toString();
@@ -218,14 +221,13 @@ public abstract class TaskExecutor
     }
 
     /**
-     * If the input field exists on the output and it is not set in the task, then it should
-     * be copied to the output.
+     * If the input field exists on the output and it is not set in the task, then it should be copied to the output.
      * 
-     * @param field the input field 
+     * @param field the input field
      */
     private void copyInputField2Output(String field) {
         // Check if the field exists and is not set on the output
-        if (!getOutgoing().containsKey(field) || getOutgoing().get(field) != null) {
+        if (getOutgoing().containsKey(field) && getOutgoing().get(field) != null) {
             return;
         }
 
@@ -316,14 +318,13 @@ public abstract class TaskExecutor
     /*
      * (non-Javadoc)
      *
-     * @see
-     * org.onap.policy.apex.core.engine.executor.Executor#setNext(org.onap.policy.apex.core.engine.
+     * @see org.onap.policy.apex.core.engine.executor.Executor#setNext(org.onap.policy.apex.core.engine.
      * executor.Executor)
      */
     @Override
     public void setNext(
-            final Executor<Map<String, Object>, Map<String, Object>, AxTask, ApexInternalContext> newNextExecutor) {
-        this.nextExecutor = newNextExecutor;
+                    final Executor<Map<String, Object>, Map<String, Object>, AxTask, ApexInternalContext> nextEx) {
+        this.nextExecutor = nextEx;
     }
 
     /*
@@ -339,10 +340,10 @@ public abstract class TaskExecutor
     /*
      * (non-Javadoc)
      *
-     * @see
-     * org.onap.policy.apex.core.engine.executor.Executor#setParameters(org.onap.policy.apex.core.
-     * engine. ExecutorParameters)
+     * @see org.onap.policy.apex.core.engine.executor.Executor#setParameters(org.onap.policy.apex.core. engine.
+     * ExecutorParameters)
      */
     @Override
-    public void setParameters(final ExecutorParameters parameters) {}
+    public void setParameters(final ExecutorParameters parameters) {
+    }
 }
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacade.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacade.java
index f7b53554d..f3906213f 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacade.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacade.java
@@ -20,7 +20,6 @@
 
 package org.onap.policy.apex.core.engine.executor.context;
 
-import org.onap.policy.apex.context.ContextRuntimeException;
 import org.onap.policy.apex.context.SchemaHelper;
 import org.onap.policy.apex.context.impl.schema.SchemaHelperFactory;
 import org.onap.policy.apex.core.engine.event.EnException;
@@ -120,7 +119,7 @@ public class AxTaskFacade {
         // Get a schema helper to handle translations of fields to and from the schema
         try {
             return new SchemaHelperFactory().createSchemaHelper(field.getKey(), field.getSchema());
-        } catch (final ContextRuntimeException e) {
+        } catch (final Exception e) {
             final String message = "schema helper cannot be created for task field \"" + fieldName + "\" with key \""
                     + field.getId() + "\" with schema \"" + field.getSchema() + "\"";
             LOGGER.warn(message, e);
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
index 63052348a..312c2a058 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContext.java
@@ -76,7 +76,7 @@ public class TaskSelectionExecutionContext {
      * sets this field in its logic prior to executing and the Apex engine executes this task as the
      * task for this state.
      */
-    public final AxArtifactKey selectedTask;
+    public AxArtifactKey selectedTask;
 
     /**
      * Logger for task selection execution, task selection logic can use this field to access and
diff --git a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
index d1f07e19a..c0e24dd5a 100644
--- a/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
+++ b/core/core-engine/src/main/java/org/onap/policy/apex/core/engine/executor/impl/ExecutorFactoryImpl.java
@@ -49,7 +49,7 @@ import org.slf4j.ext.XLoggerFactory;
  *
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
-public class ExecutorFactoryImpl extends ExecutorFactory {
+public class ExecutorFactoryImpl implements ExecutorFactory {
     // Get a reference to the logger
     private static final XLogger LOGGER = XLoggerFactory.getXLogger(ExecutorFactoryImpl.class);
 
@@ -220,7 +220,7 @@ public class ExecutorFactoryImpl extends ExecutorFactory {
             throw new StateMachineRuntimeException(errorMessage, e);
         }
 
-        // Check the class is a Task Selection Executor
+        // Check the class is the correct type of executor
         if (!(executorSuperClass.isAssignableFrom(executorObject.getClass()))) {
             final String errorMessage = "Executor on \"" + logicFlavour + "\" of type \"" + executorClass
                             + "\" is not an instance of \"" + executorSuperClass.getCanonicalName() + "\"";
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java
new file mode 100644
index 000000000..2a80cf06b
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/ApexEngineImplTest.java
@@ -0,0 +1,668 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.engine.impl;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.util.HashMap;
+
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.parameters.ContextParameterConstants;
+import org.onap.policy.apex.context.parameters.DistributorParameters;
+import org.onap.policy.apex.context.parameters.LockManagerParameters;
+import org.onap.policy.apex.context.parameters.PersistorParameters;
+import org.onap.policy.apex.context.parameters.SchemaParameters;
+import org.onap.policy.apex.core.engine.EngineParameterConstants;
+import org.onap.policy.apex.core.engine.EngineParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.StateMachineExecutor;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexRuntimeException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.enginemodel.concepts.AxEngineState;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicy;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.common.parameters.ParameterService;
+
+/**
+ * Test the engine implementation.
+ */
+public class ApexEngineImplTest {
+    private AxPolicyModel policyModel;
+    private AxPolicyModel incompatiblePolicyModel;
+    private AxPolicyModel policyModelWithStates;
+
+    @Mock
+    StateMachineHandler smHandlerMock;
+
+    /**
+     * Set up services.
+     */
+    @BeforeClass
+    public static void setup() {
+        ParameterService.register(new SchemaParameters());
+        ParameterService.register(new DistributorParameters());
+        ParameterService.register(new LockManagerParameters());
+        ParameterService.register(new PersistorParameters());
+        ParameterService.register(new EngineParameters());
+    }
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void initializeMocking() throws ApexException {
+        MockitoAnnotations.initMocks(this);
+
+        Mockito.doThrow(new StateMachineException("mocked state machine exception",
+                        new IOException("nexted exception"))).when(smHandlerMock).execute(Mockito.anyObject());
+    }
+
+    /**
+     * Create policy models.
+     */
+    @Before
+    public void createPolicyModels() {
+        AxArtifactKey modelKey = new AxArtifactKey("PolicyModel:0.0.1");
+        policyModel = new AxPolicyModel(modelKey);
+
+        AxArtifactKey schemaKey = new AxArtifactKey("Schema:0.0.1");
+        AxContextSchema schema = new AxContextSchema(schemaKey, "Java", "java.lang.String");
+        policyModel.getSchemas().getSchemasMap().put(schemaKey, schema);
+
+        AxArtifactKey albumKey = new AxArtifactKey("Album:0.0.1");
+        AxContextAlbum album = new AxContextAlbum(albumKey, "Policy", true, schemaKey);
+
+        policyModel.getAlbums().getAlbumsMap().put(albumKey, album);
+
+        AxEvents events = new AxEvents();
+        AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
+        AxEvent event = new AxEvent(eventKey, "event.name.space", "source", "target");
+        events.getEventMap().put(eventKey, event);
+        policyModel.setEvents(events);
+
+        AxArtifactKey incompatibleModelKey = new AxArtifactKey("IncompatiblePolicyModel:0.0.2");
+        incompatiblePolicyModel = new AxPolicyModel(incompatibleModelKey);
+
+        AxArtifactKey incompatibleSchemaKey = new AxArtifactKey("IncompatibleSchema:0.0.1");
+        AxContextSchema incompatibleSchema = new AxContextSchema(incompatibleSchemaKey, "Java", "java.lang.Integer");
+        incompatiblePolicyModel.getSchemas().getSchemasMap().put(incompatibleSchemaKey, incompatibleSchema);
+
+        AxContextAlbum incompatibleAlbum = new AxContextAlbum(albumKey, "Policy", true, incompatibleSchemaKey);
+        incompatiblePolicyModel.getAlbums().getAlbumsMap().put(albumKey, incompatibleAlbum);
+
+        AxArtifactKey modelKeyStates = new AxArtifactKey("PolicyModelStates:0.0.1");
+        policyModelWithStates = new AxPolicyModel(modelKeyStates);
+        policyModelWithStates.getSchemas().getSchemasMap().put(schemaKey, schema);
+        policyModelWithStates.getAlbums().getAlbumsMap().put(albumKey, album);
+        policyModelWithStates.setEvents(events);
+
+        AxPolicy policy0 = new AxPolicy(new AxArtifactKey("Policy0:0.0.1"));
+        AxState state0 = new AxState(new AxReferenceKey(policy0.getKey(), "state0"));
+        state0.setTrigger(eventKey);
+        policy0.getStateMap().put(state0.getKey().getLocalName(), state0);
+        policy0.setFirstState(state0.getKey().getLocalName());
+
+        policyModelWithStates.getPolicies().getPolicyMap().put(policy0.getKey(), policy0);
+
+        AxPolicy policy1 = new AxPolicy(new AxArtifactKey("Policy1:0.0.1"));
+        AxState state1 = new AxState(new AxReferenceKey(policy1.getKey(), "state1"));
+        state1.setTrigger(eventKey);
+        policy1.getStateMap().put(state1.getKey().getLocalName(), state1);
+        policy1.setFirstState(state1.getKey().getLocalName());
+
+        policyModelWithStates.getPolicies().getPolicyMap().put(policy1.getKey(), policy1);
+    }
+
+    /**
+     * Clear registrations.
+     */
+    @AfterClass
+    public static void teardown() {
+        ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
+        ParameterService.deregister(ContextParameterConstants.DISTRIBUTOR_GROUP_NAME);
+        ParameterService.deregister(ContextParameterConstants.LOCKING_GROUP_NAME);
+        ParameterService.deregister(ContextParameterConstants.PERSISTENCE_GROUP_NAME);
+        ParameterService.deregister(EngineParameterConstants.MAIN_GROUP_NAME);
+    }
+
+    @Test
+    public void testSanity() {
+        AxArtifactKey engineKey = new AxArtifactKey("Engine:0.0.1");
+        ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
+        assertNotNull(engine);
+        assertEquals(engineKey, engine.getKey());
+
+        try {
+            engine.start();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
+                            + "engine has not been initialized, its model is not loaded", ae.getMessage());
+        }
+
+        try {
+            engine.stop();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("stop()<-Engine:0.0.1,STOPPED, cannot stop engine, " + "engine is already stopped",
+                            ae.getMessage());
+        }
+
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+        assertEquals(0, engine.getEngineContext().size());
+        assertEquals(engineKey, engine.getEngineStatus().getKey());
+        assertNull(engine.getInternalContext());
+
+        try {
+            engine.clear();
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.addEventListener(null, null);
+            fail("test should throw an exception");
+        } catch (ApexRuntimeException ae) {
+            assertEquals("addEventListener()<-Engine:0.0.1,STOPPED, listenerName is null", ae.getMessage());
+        }
+
+        try {
+            engine.addEventListener("myListener", null);
+            fail("test should throw an exception");
+        } catch (ApexRuntimeException ae) {
+            assertEquals("addEventListener()<-Engine:0.0.1,STOPPED, listener is null", ae.getMessage());
+        }
+
+        try {
+            engine.removeEventListener(null);
+            fail("test should throw an exception");
+        } catch (ApexRuntimeException ae) {
+            assertEquals("removeEventListener()<-Engine:0.0.1,STOPPED, listenerName is null", ae.getMessage());
+        }
+
+        try {
+            engine.addEventListener("myListener", new DummyListener());
+            engine.removeEventListener("myListener");
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        assertNull(engine.createEvent(null));
+
+        assertFalse(engine.handleEvent(null));
+
+        try {
+            engine.updateModel(null);
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("updateModel()<-Engine:0.0.1, Apex model is not defined, it has a null value",
+                            ae.getMessage());
+        }
+
+        try {
+            engine.updateModel(policyModel);
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        // Force a context exception
+        ModelService.registerModel(AxPolicyModel.class, new AxPolicyModel());
+        try {
+            engine.updateModel(incompatiblePolicyModel);
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("updateModel()<-Engine:0.0.1, error setting the context for engine \"Engine:0.0.1\"",
+                            ae.getMessage());
+        }
+
+        try {
+            engine.updateModel(policyModel);
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertNotNull(engine.getInternalContext());
+        assertEquals(1, engine.getEngineContext().size());
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("start()<-Engine:0.0.1,READY, cannot start engine, engine not in state STOPPED",
+                            ae.getMessage());
+        }
+
+        try {
+            engine.clear();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("clear()<-Engine:0.0.1,READY, cannot clear engine, engine is not stopped", ae.getMessage());
+        }
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.clear();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
+                            + "engine has not been initialized, its model is not loaded", ae.getMessage());
+        }
+
+        try {
+            engine.updateModel(policyModel);
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertNull(engine.createEvent(null));
+
+        AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
+        EnEvent event = engine.createEvent(eventKey);
+        assertEquals(eventKey, event.getKey());
+
+        assertTrue(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.addEventListener("myListener", new DummyListener());
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.updateModel(policyModel);
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("updateModel()<-Engine:0.0.1, cannot update model, "
+                            + "engine should be stopped but is in state READY", ae.getMessage());
+        }
+
+        assertTrue(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.addEventListener("badListener", new BadListener());
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertFalse(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.removeEventListener("badListener");
+            engine.addEventListener("slowListener", new SlowListener());
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+    }
+
+    @Test
+    public void testState() throws InterruptedException {
+        AxArtifactKey engineKey = new AxArtifactKey("Engine:0.0.1");
+        ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
+        assertNotNull(engine);
+        assertEquals(engineKey, engine.getKey());
+
+        try {
+            engine.updateModel(policyModel);
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        SlowListener slowListener = new SlowListener();
+        try {
+            engine.addEventListener("slowListener", slowListener);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
+        EnEvent event = engine.createEvent(eventKey);
+        assertEquals(eventKey, event.getKey());
+
+        // 1 second is less than the 3 second wait on engine stopping
+        slowListener.setWaitTime(1000);
+        (new Thread() {
+            public void run() {
+                assertTrue(engine.handleEvent(event));
+                assertEquals(AxEngineState.STOPPED, engine.getState());
+            }
+        }).start();
+
+        Thread.sleep(50);
+        assertEquals(AxEngineState.EXECUTING, engine.getState());
+
+        assertFalse(engine.handleEvent(event));
+        assertNotNull(engine.createEvent(eventKey));
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+
+        // 4 seconds is more than the 3 second wait on engine stopping
+        slowListener.setWaitTime(4000);
+        (new Thread() {
+            public void run() {
+                assertTrue(engine.handleEvent(event));
+                assertEquals(AxEngineState.STOPPED, engine.getState());
+            }
+        }).start();
+
+        Thread.sleep(50);
+        assertEquals(AxEngineState.EXECUTING, engine.getState());
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("stop()<-Engine:0.0.1,STOPPED, error stopping engine, engine stop timed out", ae.getMessage());
+        }
+
+        try {
+            engine.clear();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+    }
+
+    @Test
+    public void testStateMachineError() throws InterruptedException, IllegalArgumentException, IllegalAccessException,
+                    NoSuchFieldException, SecurityException {
+
+        AxArtifactKey engineKey = new AxArtifactKey("Engine:0.0.1");
+        ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
+        assertNotNull(engine);
+        assertEquals(engineKey, engine.getKey());
+
+        try {
+            engine.updateModel(policyModel);
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        final Field smHandlerField = engine.getClass().getDeclaredField("stateMachineHandler");
+        smHandlerField.setAccessible(true);
+        smHandlerField.set(engine, smHandlerMock);
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
+        EnEvent event = engine.createEvent(eventKey);
+        assertEquals(eventKey, event.getKey());
+
+        assertFalse(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            Mockito.doThrow(new StateMachineException("mocked state machine exception",
+                            new IOException("nexted exception"))).when(smHandlerMock).start();
+
+            engine.start();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("updateModel()<-Engine:0.0.1, error starting the engine state machines \"Engine:0.0.1\"",
+                            ae.getMessage());
+        }
+
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+
+        try {
+            engine.clear();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+    }
+
+    @Test
+    public void testStateMachineHandler() throws InterruptedException, IllegalArgumentException, IllegalAccessException,
+                    NoSuchFieldException, SecurityException {
+        AxArtifactKey engineKey = new AxArtifactKey("Engine:0.0.1");
+        ApexEngineImpl engine = (ApexEngineImpl) new ApexEngineFactory().createApexEngine(engineKey);
+        assertNotNull(engine);
+        assertEquals(engineKey, engine.getKey());
+
+        try {
+            engine.updateModel(policyModelWithStates);
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
+        EnEvent event = engine.createEvent(eventKey);
+        assertEquals(eventKey, event.getKey());
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+        
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        // Can't work, state is not fully defined
+        assertFalse(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        final Field smHandlerField = engine.getClass().getDeclaredField("stateMachineHandler");
+        smHandlerField.setAccessible(true);
+        StateMachineHandler smHandler = (StateMachineHandler) smHandlerField.get(engine);
+
+        final Field smExecutorMapField = smHandler.getClass().getDeclaredField("stateMachineExecutorMap");
+        smExecutorMapField.setAccessible(true);
+        @SuppressWarnings("unchecked")
+        HashMap<AxEvent, StateMachineExecutor> smExMap = (HashMap<AxEvent, StateMachineExecutor>) smExecutorMapField
+                        .get(smHandler);
+
+        assertEquals(1, smExMap.size());
+        DummySmExecutor dummyExecutor = new DummySmExecutor(null, event.getKey());
+        smExMap.put(event.getAxEvent(), dummyExecutor);
+        
+        try {
+            ApexInternalContext internalContext = new ApexInternalContext(policyModelWithStates);
+            dummyExecutor.setContext(null, null, internalContext);
+        } catch (Exception e) {
+            // Ignore this exception, we just need to set the internal context
+        }
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+        
+        try {
+            engine.start();
+            fail("test should throw an exception");
+        } catch (ApexException ae) {
+            assertEquals("updateModel()<-Engine:0.0.1, error starting the engine state machines \"Engine:0.0.1\"",
+                            ae.getMessage());
+        }
+
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+
+        try {
+            engine.start();
+            assertEquals(AxEngineState.READY, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+
+        // Works, Dummy executor fakes event execution
+        assertTrue(engine.handleEvent(event));
+        assertEquals(AxEngineState.READY, engine.getState());
+
+        try {
+            engine.stop();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException ae) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            engine.clear();
+            assertEquals(AxEngineState.STOPPED, engine.getState());
+        } catch (ApexException e) {
+            fail("test should not throw an exception");
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/BadListener.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/BadListener.java
new file mode 100644
index 000000000..b829437d6
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/BadListener.java
@@ -0,0 +1,43 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.engine.impl;
+
+import org.onap.policy.apex.core.engine.engine.EnEventListener;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+
+/**
+ * Dummy engine event listener for unit test.
+ *
+ */
+public class BadListener implements EnEventListener {
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.onap.policy.apex.core.engine.engine.EnEventListener#onEnEvent(org.onap.policy.apex.core.engine.event.EnEvent)
+     */
+    @Override
+    public void onEnEvent(EnEvent enEvent) throws ApexException {
+        throw new ApexException("not implemented on dummy class");
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java
new file mode 100644
index 000000000..33b434af1
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummyListener.java
@@ -0,0 +1,43 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.engine.impl;
+
+import org.onap.policy.apex.core.engine.engine.EnEventListener;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+
+/**
+ * Dummy engine event listener for unit test.
+ *
+ */
+public class DummyListener implements EnEventListener {
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.onap.policy.apex.core.engine.engine.EnEventListener#onEnEvent(org.onap.policy.apex.core.engine.event.EnEvent)
+     */
+    @Override
+    public void onEnEvent(EnEvent enEvent) throws ApexException {
+        // Do nothing
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java
new file mode 100644
index 000000000..db8fc32d9
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/DummySmExecutor.java
@@ -0,0 +1,87 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.engine.impl;
+
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.ExecutorFactory;
+import org.onap.policy.apex.core.engine.executor.StateMachineExecutor;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+
+/**
+ * Dummy state machine executor for testing.
+ */
+public class DummySmExecutor extends StateMachineExecutor {
+    private boolean cleanupWorks = false;
+    private boolean prepareWorks;
+    
+    /**
+     * Constructor.
+     * 
+     * @param executorFactory the factory for executors
+     * @param owner the owner key
+     */
+    public DummySmExecutor(ExecutorFactory executorFactory, AxArtifactKey owner) {
+        super(executorFactory, owner);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#prepare()
+     */
+    @Override
+    public void prepare() throws StateMachineException {
+        if (prepareWorks) {
+            prepareWorks = false;
+        }
+        else {
+            prepareWorks = true;
+            throw new StateMachineException("dummy state machine executor exception");
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#executeDirected(java.lang.long, java.lang.Object)
+     */
+    @Override
+    public EnEvent execute(final long executionId, final EnEvent incomingEvent) {
+        return incomingEvent;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#cleanUp()
+     */
+    @Override
+    public void cleanUp() throws StateMachineException {
+        if (cleanupWorks) {
+            cleanupWorks = false;
+        }
+        else {
+            cleanupWorks = true;
+            throw new StateMachineException("dummy state machine executor exception");
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/SlowListener.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/SlowListener.java
new file mode 100644
index 000000000..f3f885911
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/engine/impl/SlowListener.java
@@ -0,0 +1,58 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.engine.impl;
+
+import org.onap.policy.apex.core.engine.engine.EnEventListener;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+
+/**
+ * Dummy engine event listener for unit test.
+ *
+ */
+public class SlowListener implements EnEventListener {
+
+    private long waitTime;
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.onap.policy.apex.core.engine.engine.EnEventListener#onEnEvent(org.onap.policy.apex.core.engine.event.EnEvent)
+     */
+    @Override
+    public void onEnEvent(EnEvent enEvent) throws ApexException {
+        try {
+            Thread.sleep(waitTime);
+        }
+        catch (InterruptedException ie) {
+            // Do nothing
+        }
+    }
+
+    public long getWaitTime() {
+        return waitTime;
+    }
+
+    public void setWaitTime(long waitTime) {
+        this.waitTime = waitTime;
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java
new file mode 100644
index 000000000..4d4fb639f
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyFailingTaskExecutor.java
@@ -0,0 +1,30 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+/**
+ * Dummy task executor for testing.
+ */
+public class DummyFailingTaskExecutor extends TaskExecutor {
+    public DummyFailingTaskExecutor() throws InstantiationException {
+        throw new InstantiationException("I always fail");
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java
new file mode 100644
index 000000000..abc11871e
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyStateFinalizerExecutor.java
@@ -0,0 +1,68 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import java.util.Map;
+
+import org.onap.policy.apex.context.ContextException;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+
+/**
+ * Dummy state finalizer executor for testing.
+ */
+public class DummyStateFinalizerExecutor extends StateFinalizerExecutor {
+    private boolean override;
+    
+    private boolean returnBad;
+
+    public DummyStateFinalizerExecutor() {
+        this(false);
+    }
+    
+    public DummyStateFinalizerExecutor(final boolean override) {
+        this.override = override;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#execute(java.lang.long, java.lang.Object)
+     */
+    @Override
+    public String execute(final long executionId, final Map<String, Object> newIncomingFields)
+                    throws StateMachineException, ContextException {
+        
+        if (!override) {
+            super.execute(executionId, newIncomingFields);
+        }
+        
+        if (returnBad) {
+            return "stateOutputBad";
+        }
+        else {
+            return "stateOutput1";
+        }
+    }
+
+    public void setReturnBad(boolean returnBad) {
+        this.returnBad = returnBad;
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java
new file mode 100644
index 000000000..93fc6190f
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskExecutor.java
@@ -0,0 +1,94 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import java.util.Map;
+
+import org.onap.policy.apex.context.ContextException;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+
+/**
+ * Dummy task executor for testing.
+ */
+public class DummyTaskExecutor extends TaskExecutor {
+    private boolean override;
+
+    public DummyTaskExecutor() {
+        this(false);
+    }
+
+    public DummyTaskExecutor(final boolean override) {
+        this.override = override;
+    }
+
+    @Override
+    public void prepare() throws StateMachineException {
+        if (!override) {
+            super.prepare();
+        }
+    }
+    
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#execute(java.lang.long, java.lang.Object)
+     */
+    @Override
+    public Map<String, Object> execute(final long executionId, final Map<String, Object> newIncomingFields)
+                    throws StateMachineException, ContextException {
+        if (!override) {
+            super.execute(executionId, newIncomingFields);
+        }
+        
+        AxArtifactKey event0Key = new AxArtifactKey("Event0:0.0.1");
+        return new EnEvent(event0Key);
+    }
+    
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#getSubject()
+     */
+    @Override
+    public AxTask getSubject() {
+        if (!override) {
+            super.getSubject();
+        }
+        
+        AxArtifactKey taskKey = new AxArtifactKey("FirstTask:0.0.1");
+        return new AxTask(taskKey);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#cleanUp()
+     */
+    @Override
+    public void cleanUp() throws StateMachineException {
+        if (!override) {
+            super.cleanUp();
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java
new file mode 100644
index 000000000..abbb1bd79
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/DummyTaskSelectExecutor.java
@@ -0,0 +1,82 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import org.onap.policy.apex.context.ContextException;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+
+/**
+ * Dummy task selection executor for testing.
+ */
+public class DummyTaskSelectExecutor extends TaskSelectExecutor {
+    private boolean override;
+
+    private static int taskNo;
+    
+    public DummyTaskSelectExecutor() {
+        this(false);
+    }
+
+    public DummyTaskSelectExecutor(final boolean override) {
+        this.override = override;
+    }
+
+    @Override
+    public void prepare() throws StateMachineException {
+        if (!override) {
+            super.prepare();
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#execute(java.lang.long, java.lang.Object)
+     */
+    @Override
+    public AxArtifactKey execute(final long executionId, final EnEvent newIncomingEvent)
+                    throws StateMachineException, ContextException {
+        if (!override) {
+            return super.execute(executionId, newIncomingEvent);
+        }
+        
+        return new AxArtifactKey("task" + (taskNo++) + ":0.0.1");
+    }
+
+    public void setTaskNo(int incomingTaskNo) {
+        taskNo = incomingTaskNo;
+    }
+    
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.engine.executor.Executor#cleanUp()
+     */
+    @Override
+    public void cleanUp() throws StateMachineException {
+        if (!override) {
+            super.cleanUp();
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java
new file mode 100644
index 000000000..08ab03b06
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateExecutorTest.java
@@ -0,0 +1,96 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+
+/**
+ * Test task executor.
+ */
+public class StateExecutorTest {
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private AxState axStateMock;
+
+    @Mock
+    private ExecutorFactory executorFactoryMock;
+
+    @Mock
+    private Executor<EnEvent, StateOutput, AxState, ApexInternalContext> nextExecutorMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+        
+        Mockito.doReturn(new AxReferenceKey("Policy:0.0.1:PolName:State0")).when(axStateMock).getKey();
+    }
+
+    @Test
+    public void testStateExecutor() {
+        StateExecutor executor = new StateExecutor(executorFactoryMock);
+
+        executor.setContext(null, axStateMock, internalContextMock);
+        assertEquals("Policy:0.0.1:PolName:State0", executor.getKey().getId());
+        assertEquals(null, executor.getParent());
+        assertEquals(internalContextMock, executor.getContext());
+        assertEquals(null, executor.getNext());
+        assertEquals(null, executor.getIncoming());
+        assertEquals(null, executor.getOutgoing());
+        assertEquals(axStateMock, executor.getSubject());
+
+        executor.setParameters(new ExecutorParameters());
+        executor.setNext(nextExecutorMock);
+        assertEquals(nextExecutorMock, executor.getNext());
+        executor.setNext(null);
+        assertEquals(null, executor.getNext());
+
+        try {
+            executor.executePre(0, null);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execution pre work not implemented on class", ex.getMessage());
+        }
+
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execution post work not implemented on class", ex.getMessage());
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java
new file mode 100644
index 000000000..82ac610c9
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateFinalizerExecutorTest.java
@@ -0,0 +1,199 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
+
+/**
+ * Test task executor.
+ */
+public class StateFinalizerExecutorTest {
+    @Mock
+    private Executor<?, ?, ?, ?> parentMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private AxStateFinalizerLogic stateFinalizerLogicMock;
+
+    @Mock
+    private Executor<Map<String, Object>, String, AxStateFinalizerLogic, ApexInternalContext> nextExecutorMock;
+
+    @Mock
+    private EnEvent incomingEvent;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+        
+        AxState state = new AxState();
+        state.getStateOutputs().put("ValidOutput", null);
+        
+        Mockito.doReturn(state).when(parentMock).getSubject();
+
+        Mockito.doReturn(new AxReferenceKey("State:0.0.1:StateName:StateSFL")).when(stateFinalizerLogicMock).getKey();
+    }
+
+    @Test
+    public void testStateFinalizerExecutor() {
+        DummyStateFinalizerExecutor executor = new DummyStateFinalizerExecutor();
+
+        executor.setContext(parentMock, stateFinalizerLogicMock, internalContextMock);
+        assertEquals("State:0.0.1:StateName:StateSFL", executor.getKey().getId());
+        assertEquals(null, executor.getExecutionContext());
+        assertEquals(parentMock, executor.getParent());
+        assertEquals(internalContextMock, executor.getContext());
+        assertEquals(null, executor.getNext());
+        assertEquals(null, executor.getIncoming());
+        assertEquals(null, executor.getOutgoing());
+        assertEquals(stateFinalizerLogicMock, executor.getSubject());
+
+        executor.setParameters(new ExecutorParameters());
+        executor.setNext(nextExecutorMock);
+        assertEquals(nextExecutorMock, executor.getNext());
+        executor.setNext(null);
+        assertEquals(null, executor.getNext());
+
+        try {
+            executor.cleanUp();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("cleanUp() not implemented on class", ex.getMessage());
+        }
+
+        Mockito.doReturn(null).when(stateFinalizerLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("state finalizer logic cannot be null.", ex.getMessage());
+        }
+
+        Mockito.doReturn("some task logic").when(stateFinalizerLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception ex) {
+            assertEquals("task input fields \"[InField0]\" are missing for task \"Task0:0.0.1\"", ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.execute(0, incomingEvent);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute() not implemented on abstract StateFinalizerExecutionContext class, "
+                            + "only on its subclasses", ex.getMessage());
+        }
+
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: state finalizer logic execution failure on state \"NULL:0.0.0:NULL:NULL\" "
+                            + "on finalizer logic null", ex.getMessage());
+        }
+
+        executor.getExecutionContext().setMessage("Execution message");
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: state finalizer logic execution failure on state \"NULL:0.0.0:NULL:NULL\" "
+                            + "on finalizer logic null, user message: Execution message", ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.executePost(true);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: state finalizer logic \"null\" did not select an output state",
+                            ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getExecutionContext().setSelectedStateOutputName("ThisOutputDoesNotExist");
+        try {
+            executor.executePost(true);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: state finalizer logic \"null\" selected output state "
+                            + "\"ThisOutputDoesNotExist\" that does not exsist on state \"NULL:0.0.0:NULL:NULL\"",
+                            ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getExecutionContext().setSelectedStateOutputName("ValidOutput");
+        try {
+            executor.executePost(true);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java
new file mode 100644
index 000000000..f9d3edc6c
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/StateMachineExecutorTest.java
@@ -0,0 +1,437 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.parameters.SchemaParameters;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvents;
+import org.onap.policy.apex.model.eventmodel.concepts.AxField;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicy;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateOutput;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskOutputType;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskReference;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTasks;
+import org.onap.policy.common.parameters.ParameterService;
+
+/**
+ * Test task executor.
+ */
+public class StateMachineExecutorTest {
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private Executor<EnEvent, EnEvent, AxPolicy, ApexInternalContext> nextExecutorMock;
+
+    @Mock
+    private ExecutorFactory executorFactoryMock;
+
+    @Mock
+    private EnEvent incomingEventMock;
+
+    private AxPolicy axPolicy = new AxPolicy();
+
+    private DummyTaskSelectExecutor dummyTsle;
+
+    private DummyStateFinalizerExecutor dummySfle;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        axPolicy.setKey(new AxArtifactKey("Policy:0.0.1"));
+
+        AxReferenceKey state0Key = new AxReferenceKey(axPolicy.getKey(), "state0");
+        AxState state0 = new AxState(state0Key);
+
+        AxReferenceKey state1Key = new AxReferenceKey(axPolicy.getKey(), "state1");
+        AxState state1 = new AxState(state1Key);
+
+        axPolicy.getStateMap().put("State0", state0);
+        axPolicy.getStateMap().put("State1", state1);
+        axPolicy.setFirstState("state0");
+
+        AxArtifactKey event0Key = new AxArtifactKey("Event0:0.0.1");
+        AxEvent event0 = new AxEvent(event0Key, "a.name.space", "source", "target");
+        AxArtifactKey event1Key = new AxArtifactKey("Event1:0.0.1");
+        AxEvent event1 = new AxEvent(event1Key, "a.name.space", "source", "target");
+        AxArtifactKey event2Key = new AxArtifactKey("Event2:0.0.1");
+        AxEvent event2 = new AxEvent(event2Key, "a.name.space", "source", "target");
+        AxEvents events = new AxEvents();
+        events.getEventMap().put(event0Key, event0);
+        events.getEventMap().put(event1Key, event1);
+        events.getEventMap().put(event2Key, event2);
+        ModelService.registerModel(AxEvents.class, events);
+
+        AxReferenceKey fieldKey = new AxReferenceKey("Event1:0.0.1:event:Field0");
+        AxArtifactKey stringSchemaKey = new AxArtifactKey("StringSchema:0.0.1");
+        AxContextSchema stringSchema = new AxContextSchema(stringSchemaKey, "Java", "java.lang.String");
+        AxContextSchemas schemas = new AxContextSchemas();
+        schemas.getSchemasMap().put(stringSchemaKey, stringSchema);
+        ModelService.registerModel(AxContextSchemas.class, schemas);
+
+        AxField event1Field0Definition = new AxField(fieldKey, stringSchemaKey);
+        event1.getParameterMap().put("Event1Field0", event1Field0Definition);
+
+        event0.getParameterMap().put("Event1Field0", event1Field0Definition);
+        event0.getParameterMap().put("UnusedField", event1Field0Definition);
+
+        Mockito.doReturn(event0Key).when(incomingEventMock).getKey();
+        Mockito.doReturn(event0).when(incomingEventMock).getAxEvent();
+
+        state0.setTrigger(event0Key);
+        state1.setTrigger(event1Key);
+
+        AxArtifactKey task0Key = new AxArtifactKey("task0:0.0.1");
+        AxTask task0 = new AxTask(task0Key);
+
+        AxArtifactKey task1Key = new AxArtifactKey("task1:0.0.1");
+        AxTask task1 = new AxTask(task1Key);
+
+        AxTasks tasks = new AxTasks();
+        tasks.getTaskMap().put(task0Key, task0);
+        tasks.getTaskMap().put(task1Key, task1);
+        ModelService.registerModel(AxTasks.class, tasks);
+
+        ParameterService.register(new SchemaParameters());
+
+        AxReferenceKey stateOutput0Key = new AxReferenceKey("Policy:0.0.1:state0:stateOutput0");
+        AxStateOutput stateOutput0 = new AxStateOutput(stateOutput0Key, event1Key, state1.getKey());
+
+        state0.getStateOutputs().put(stateOutput0Key.getLocalName(), stateOutput0);
+
+        AxReferenceKey stateOutput1Key = new AxReferenceKey("Policy:0.0.1:state0:stateOutput1");
+        AxStateOutput stateOutput1 = new AxStateOutput(stateOutput1Key, event2Key, AxReferenceKey.getNullKey());
+
+        state1.getStateOutputs().put(stateOutput1Key.getLocalName(), stateOutput1);
+
+        AxReferenceKey str0Key = new AxReferenceKey("Policy:0.0.1:state0:str0");
+        AxStateTaskReference str0 = new AxStateTaskReference(str0Key, AxStateTaskOutputType.DIRECT, stateOutput0Key);
+        state0.getTaskReferences().put(task0Key, str0);
+
+        AxReferenceKey sflKey = new AxReferenceKey("Policy:0.0.1:state1:sfl");
+        AxStateFinalizerLogic sfl = new AxStateFinalizerLogic(sflKey, "Java", "State fianlizer logic");
+        state1.getStateFinalizerLogicMap().put("sfl", sfl);
+
+        AxReferenceKey str1Key = new AxReferenceKey("Policy:0.0.1:state1:str1");
+        AxStateTaskReference str1 = new AxStateTaskReference(str1Key, AxStateTaskOutputType.LOGIC, sflKey);
+        state1.getTaskReferences().put(task1Key, str1);
+
+        Mockito.doReturn(new DummyTaskExecutor(true)).when(executorFactoryMock).getTaskExecutor(Mockito.anyObject(),
+                        Mockito.anyObject(), Mockito.anyObject());
+
+        dummyTsle = new DummyTaskSelectExecutor(true);
+        Mockito.doReturn(dummyTsle).when(executorFactoryMock).getTaskSelectionExecutor(Mockito.anyObject(),
+                        Mockito.anyObject(), Mockito.anyObject());
+
+        dummySfle = new DummyStateFinalizerExecutor(true);
+        Mockito.doReturn(dummySfle).when(executorFactoryMock).getStateFinalizerExecutor(Mockito.anyObject(),
+                        Mockito.anyObject(), Mockito.anyObject());
+    }
+
+    @After
+    public void cleardown() {
+        ParameterService.clear();
+        ModelService.clear();
+    }
+
+    @Test
+    public void testStateMachineExecutor() {
+        StateMachineExecutor executor = new StateMachineExecutor(executorFactoryMock,
+                        new AxArtifactKey("OwnerKey:0.0.1"));
+
+        try {
+            executor.execute(0, incomingEventMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("no states defined on state machine", ex.getMessage());
+        }
+
+        executor.setContext(null, axPolicy, internalContextMock);
+        assertEquals("Policy:0.0.1", executor.getKey().getId());
+        assertEquals(null, executor.getParent());
+        assertEquals(internalContextMock, executor.getContext());
+        assertEquals(null, executor.getNext());
+        assertEquals(null, executor.getIncoming());
+        assertEquals(null, executor.getOutgoing());
+        assertEquals(axPolicy, executor.getSubject());
+
+        executor.setParameters(new ExecutorParameters());
+        executor.setNext(nextExecutorMock);
+        assertEquals(nextExecutorMock, executor.getNext());
+        executor.setNext(null);
+        assertEquals(null, executor.getNext());
+
+        try {
+            executor.executePre(0, null);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execution pre work not implemented on class", ex.getMessage());
+        }
+
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execution post work not implemented on class", ex.getMessage());
+        }
+
+        try {
+            executor.prepare();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        axPolicy.setFirstState("BadState");
+        executor.setContext(null, axPolicy, internalContextMock);
+        try {
+            executor.execute(0, incomingEventMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("first state not defined on state machine", ex.getMessage());
+        }
+
+        axPolicy.setFirstState("state0");
+        executor.setContext(null, axPolicy, internalContextMock);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        AxReferenceKey badStateKey = new AxReferenceKey("Policy:0.0.1:PName:BadState");
+        axPolicy.getStateMap().get("State1").getStateOutputs().get("stateOutput1").setNextState(badStateKey);
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("state execution failed, next state \"Policy:0.0.1:PName:BadState\" not found",
+                            ex.getMessage());
+        }
+
+        axPolicy.getStateMap().get("State1").getStateOutputs().get("stateOutput1")
+                        .setNextState(AxReferenceKey.getNullKey());
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        axPolicy.getStateMap().get("State1").setTrigger(new AxArtifactKey("BadTrigger:0.0.1"));
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("incoming event \"Event1:0.0.1\" does not match trigger \"BadTrigger:0.0.1\" "
+                            + "of state \"Policy:0.0.1:NULL:state1\"", ex.getMessage());
+        }
+
+        axPolicy.getStateMap().get("State1").setTrigger(new AxArtifactKey("Event1:0.0.1"));
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        AxStateFinalizerLogic savedSfl = axPolicy.getStateMap().get("State1").getStateFinalizerLogicMap().get("sfl");
+        axPolicy.getStateMap().get("State1").getStateFinalizerLogicMap().put("sfl", null);
+        try {
+            executor.setContext(null, axPolicy, internalContextMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("state finalizer logic on task reference "
+                            + "\"AxStateTaskReference:(stateKey=AxReferenceKey:(parentKeyName=Policy,"
+                            + "parentKeyVersion=0.0.1,parentLocalName=state1,localName=str1),"
+                            + "outputType=LOGIC,output=AxReferenceKey:(parentKeyName=Policy,parentKeyVersion=0.0.1,"
+                            + "parentLocalName=state1,localName=sfl))\" on state \"Policy:0.0.1:NULL:state1\" "
+                            + "does not exist", ex.getMessage());
+        }
+
+        axPolicy.getStateMap().get("State1").getStateFinalizerLogicMap().put("sfl", savedSfl);
+        executor.setContext(null, axPolicy, internalContextMock);
+
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        AxArtifactKey task1Key = new AxArtifactKey("task1:0.0.1");
+        try {
+            axPolicy.getStateMap().get("State1").getTaskReferences().get(task1Key)
+                            .setStateTaskOutputType(AxStateTaskOutputType.UNDEFINED);
+            executor.setContext(null, axPolicy, internalContextMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("invalid state output type on task reference \"AxStateTaskReference:(stateKey=AxReferenceKey:"
+                            + "(parentKeyName=Policy,parentKeyVersion=0.0.1,parentLocalName=state1,localName=str1),"
+                            + "outputType=UNDEFINED,output=AxReferenceKey:(parentKeyName=Policy,"
+                            + "parentKeyVersion=0.0.1,parentLocalName=state1,localName=sfl))\" "
+                            + "on state \"Policy:0.0.1:NULL:state1\"", ex.getMessage());
+        }
+
+        axPolicy.getStateMap().get("State1").getTaskReferences().get(task1Key)
+                        .setStateTaskOutputType(AxStateTaskOutputType.LOGIC);
+        executor.setContext(null, axPolicy, internalContextMock);
+
+        dummyTsle.setTaskNo(0);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        dummyTsle.setTaskNo(0);
+        dummySfle.setReturnBad(true);
+        try {
+            executor.execute(0, incomingEventMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("State execution of state \"Policy:0.0.1:NULL:state1\" on task \"task1:0.0.1\" failed: "
+                            + "state output definition for state output \"stateOutputBad\" not found for "
+                            + "state \"Policy:0.0.1:NULL:state1\"", ex.getMessage());
+        }
+
+        dummyTsle.setTaskNo(0);
+        dummySfle.setReturnBad(false);
+        try {
+            executor.execute(0, incomingEventMock);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.cleanUp();
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+    }
+
+    @Test
+    public void testStateOutput() {
+        StateOutput output = new StateOutput(
+                        axPolicy.getStateMap().get("State0").getStateOutputs().get("stateOutput0"));
+        assertNotNull(output);
+
+        assertEquals("stateOutput0", output.getStateOutputDefinition().getKey().getLocalName());
+
+        try {
+            output.setEventFields(null, null);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("incomingFieldDefinitionMap may not be null", ex.getMessage());
+        }
+
+        Map<String, AxField> incomingFieldDefinitionMap = new LinkedHashMap<>();
+        try {
+            output.setEventFields(incomingFieldDefinitionMap, null);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("eventFieldMap may not be null", ex.getMessage());
+        }
+
+        Map<String, Object> eventFieldMap = new LinkedHashMap<>();
+        try {
+            output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        eventFieldMap.put("key", "Value");
+        try {
+            output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("field definitions and values do not match for event Event1:0.0.1\n[]\n[key]",
+                            ex.getMessage());
+        }
+
+        AxField axBadFieldDefinition = new AxField();
+        incomingFieldDefinitionMap.put("key", axBadFieldDefinition);
+        try {
+            output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("field \"key\" does not exist on event \"Event1:0.0.1\"", ex.getMessage());
+        }
+
+        incomingFieldDefinitionMap.clear();
+        eventFieldMap.clear();
+        AxArtifactKey stringSchemaKey = new AxArtifactKey("StringSchema:0.0.1");
+        AxReferenceKey fieldKey = new AxReferenceKey("Event1:0.0.1:event:Field0");
+        AxField event1Field0Definition = new AxField(fieldKey, stringSchemaKey);
+        incomingFieldDefinitionMap.put("Event1Field0", event1Field0Definition);
+        eventFieldMap.put("Event1Field0", "Value");
+        try {
+            output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        output = new StateOutput(axPolicy.getStateMap().get("State0").getStateOutputs().get("stateOutput0"));
+
+        EnEvent incomingEvent = new EnEvent(new AxArtifactKey("Event0:0.0.1"));
+        output.copyUnsetFields(incomingEvent);
+
+        incomingEvent.put("Event1Field0", "Hello");
+        output.copyUnsetFields(incomingEvent);
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java
new file mode 100644
index 000000000..bfc8e2b6d
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskExecutorTest.java
@@ -0,0 +1,251 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.eventmodel.concepts.AxInputField;
+import org.onap.policy.apex.model.eventmodel.concepts.AxOutputField;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
+
+/**
+ * Test task excutor.
+ */
+public class TaskExecutorTest {
+    @Mock
+    private AxTask axTaskMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private AxInputField axInputFieldMock;
+
+    @Mock
+    private AxInputField axOptionalInputFieldMock;
+
+    @Mock
+    private AxOutputField axOutputFieldMock;
+
+    @Mock
+    private AxOutputField axOptionalOutputFieldMock;
+
+    @Mock
+    private AxOutputField axMissingOutputFieldMock;
+
+    @Mock
+    private Executor<Map<String, Object>, Map<String, Object>, AxTask, ApexInternalContext> nextExecutorMock;
+
+    @Mock
+    private AxTaskLogic taskLogicMock;
+
+    private LinkedHashMap<String, Object> inFieldMap;
+    private LinkedHashMap<String, Object> outFieldMap;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        AxArtifactKey task0Key = new AxArtifactKey("Task0:0.0.1");
+        Mockito.doReturn(task0Key).when(axTaskMock).getKey();
+        Mockito.doReturn(task0Key.getId()).when(axTaskMock).getId();
+
+        inFieldMap = new LinkedHashMap<>();
+        outFieldMap = new LinkedHashMap<>();
+
+        inFieldMap.put("InField0", axInputFieldMock);
+        inFieldMap.put("InField1", axOptionalInputFieldMock);
+        outFieldMap.put("OutField0", axOutputFieldMock);
+        outFieldMap.put("OutField0", axOptionalOutputFieldMock);
+
+        AxArtifactKey schemaKey = new AxArtifactKey("Schema:0.0.1");
+        Mockito.doReturn(schemaKey).when(axInputFieldMock).getSchema();
+        Mockito.doReturn(schemaKey).when(axOptionalInputFieldMock).getSchema();
+        Mockito.doReturn(schemaKey).when(axOutputFieldMock).getSchema();
+        Mockito.doReturn(schemaKey).when(axOptionalOutputFieldMock).getSchema();
+        Mockito.doReturn(schemaKey).when(axMissingOutputFieldMock).getSchema();
+
+        Mockito.doReturn(true).when(axOptionalInputFieldMock).getOptional();
+        Mockito.doReturn(true).when(axOptionalOutputFieldMock).getOptional();
+        Mockito.doReturn(false).when(axMissingOutputFieldMock).getOptional();
+
+        Mockito.doReturn(inFieldMap).when(axTaskMock).getInputFields();
+        Mockito.doReturn(outFieldMap).when(axTaskMock).getOutputFields();
+        Mockito.doReturn(taskLogicMock).when(axTaskMock).getTaskLogic();
+
+        Mockito.doReturn(new AxArtifactKey("Context:0.0.1")).when(internalContextMock).getKey();
+    }
+
+    @Test
+    public void testTaskExecutor() {
+        DummyTaskExecutor executor = new DummyTaskExecutor();
+
+        executor.setContext(null, axTaskMock, internalContextMock);
+        assertEquals("Task0:0.0.1", executor.getKey().getId());
+        assertEquals(null, executor.getExecutionContext());
+        assertEquals(null, executor.getParent());
+        assertEquals(internalContextMock, executor.getContext());
+        assertEquals(null, executor.getNext());
+        assertEquals(null, executor.getIncoming());
+        assertEquals(null, executor.getOutgoing());
+        assertNotNull(executor.getSubject());
+
+        executor.setParameters(new ExecutorParameters());
+        executor.setNext(nextExecutorMock);
+        assertEquals(nextExecutorMock, executor.getNext());
+        executor.setNext(null);
+        assertEquals(null, executor.getNext());
+
+        try {
+            executor.cleanUp();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("cleanUp() not implemented on class", ex.getMessage());
+        }
+
+        Mockito.doReturn(null).when(taskLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("task logic cannot be null.", ex.getMessage());
+        }
+
+        Mockito.doReturn("some task logic").when(taskLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        Map<String, Object> incomingFields = new LinkedHashMap<>();
+        try {
+            executor.executePre(0, incomingFields);
+        } catch (Exception ex) {
+            assertEquals("task input fields \"[InField0]\" are missing for task \"Task0:0.0.1\"", ex.getMessage());
+        }
+
+        incomingFields.put("InField0", "A Value");
+        try {
+            executor.executePre(0, incomingFields);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.execute(0, incomingFields);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute() not implemented on abstract TaskExecutor class, only on its subclasses",
+                            ex.getMessage());
+        }
+
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: task logic execution failure on task \"Task0\" in model Context:0.0.1",
+                            ex.getMessage());
+        }
+
+        executor.getExecutionContext().setMessage("Execution message");
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: task logic execution failure on task \"Task0\" in model Context:0.0.1, "
+                            + "user message: Execution message", ex.getMessage());
+        }
+
+        try {
+            executor.executePost(true);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        outFieldMap.put("MissingField", axMissingOutputFieldMock);
+        try {
+            executor.executePost(true);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("task output fields \"[MissingField]\" are missing for task \"Task0:0.0.1\"", ex.getMessage());
+        }
+
+        outFieldMap.remove("MissingField");
+        executor.getExecutionContext().outFields.put("BadExtraField", "Howdy!");
+        try {
+            executor.executePost(true);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("task output fields \"[BadExtraField]\" are unwanted for task \"Task0:0.0.1\"",
+                            ex.getMessage());
+        }
+
+        executor.getExecutionContext().outFields.remove("BadExtraField");
+        outFieldMap.put("InField1", axMissingOutputFieldMock);
+        try {
+            executor.executePost(true);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        outFieldMap.put("InField0", axMissingOutputFieldMock);
+        try {
+            executor.executePost(true);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getExecutionContext().outFields.put("InField0", "Output Value");
+        try {
+            executor.executePost(true);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getExecutionContext().outFields.remove("InField0");
+        try {
+            executor.executePost(true);
+        } catch (Exception ex) {
+            fail("test should not throw an exception");
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java
new file mode 100644
index 000000000..b303df06a
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/TaskSelectExecutorTest.java
@@ -0,0 +1,208 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskReference;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskSelectionLogic;
+
+/**
+ * Test task executor.
+ */
+public class TaskSelectExecutorTest {
+    @Mock
+    private AxState axStateMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private Executor<EnEvent, AxArtifactKey, AxState, ApexInternalContext> nextExecutorMock;
+
+    @Mock
+    private AxTaskSelectionLogic taskSelectionLogicMock;
+
+    @Mock
+    private EnEvent incomingEvent;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        AxReferenceKey state0Key = new AxReferenceKey("State0Parent:0.0.1:Parent:State0");
+        Mockito.doReturn(state0Key).when(axStateMock).getKey();
+        Mockito.doReturn(state0Key.getId()).when(axStateMock).getId();
+        
+        Map<AxArtifactKey, AxStateTaskReference> taskReferences = new LinkedHashMap<>();
+        taskReferences.put(new AxArtifactKey("Task0:0.0.0"), null);
+        taskReferences.put(new AxArtifactKey("Task1:0.0.0"), null);
+        Mockito.doReturn(taskReferences).when(axStateMock).getTaskReferences();
+        Mockito.doReturn(new AxArtifactKey("Task1:0.0.0")).when(axStateMock).getDefaultTask();
+
+        Mockito.doReturn(taskSelectionLogicMock).when(axStateMock).getTaskSelectionLogic();
+
+        Mockito.doReturn(new AxArtifactKey("Context:0.0.1")).when(internalContextMock).getKey();
+    }
+
+    @Test
+    public void testTaskSelectionExecutor() {
+        DummyTaskSelectExecutor executor = new DummyTaskSelectExecutor();
+
+        executor.setContext(null, axStateMock, internalContextMock);
+        assertEquals("State0Parent:0.0.1:Parent:State0", executor.getKey().getId());
+        assertEquals(null, executor.getExecutionContext());
+        assertEquals(null, executor.getParent());
+        assertEquals(internalContextMock, executor.getContext());
+        assertEquals(null, executor.getNext());
+        assertEquals(null, executor.getIncoming());
+        assertEquals(null, executor.getOutgoing());
+        assertEquals(axStateMock, executor.getSubject());
+
+        executor.setParameters(new ExecutorParameters());
+        executor.setNext(nextExecutorMock);
+        assertEquals(nextExecutorMock, executor.getNext());
+        executor.setNext(null);
+        assertEquals(null, executor.getNext());
+
+        try {
+            executor.cleanUp();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("cleanUp() not implemented on class", ex.getMessage());
+        }
+
+        Mockito.doReturn(null).when(taskSelectionLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("task selection logic cannot be null.", ex.getMessage());
+        }
+
+        Mockito.doReturn("some task logic").when(taskSelectionLogicMock).getLogic();
+
+        try {
+            executor.prepare();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception ex) {
+            assertEquals("task input fields \"[InField0]\" are missing for task \"Task0:0.0.1\"", ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.execute(0, incomingEvent);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute() not implemented on class", ex.getMessage());
+        }
+
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: task selection logic failed on state \"State0Parent:0.0.1:Parent:State0\"",
+                            ex.getMessage());
+        }
+
+        executor.getExecutionContext().setMessage("Execution message");
+        try {
+            executor.executePost(false);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("execute-post: task selection logic failed on state \"State0Parent:0.0.1:Parent:State0\", "
+                            + "user message: Execution message", ex.getMessage());
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.executePost(true);
+            assertEquals("Task1", executor.getOutgoing().getName());
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getOutgoing().setName("IDontExist");
+        try {
+            executor.executePost(true);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("task \"IDontExist:0.0.0\" returned by task selection logic not defined "
+                            + "on state \"State0Parent:0.0.1:Parent:State0\"", ex.getMessage());
+        }
+        
+        try {
+            executor.executePre(0, incomingEvent);
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+
+        executor.getOutgoing().setName("Task0");
+        
+        try {
+            executor.executePost(true);
+            assertEquals("Task0", executor.getOutgoing().getName());
+        } catch (Exception e) {
+            fail("test should not throw an exception");
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java
new file mode 100644
index 000000000..a35af534e
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxStateFacadeTest.java
@@ -0,0 +1,87 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTasks;
+
+/**
+ * Test the state facade.
+ */
+public class AxStateFacadeTest {
+    @Mock
+    private AxState axStateMock;
+
+    @Mock
+    private AxTask axTaskMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+        
+        AxReferenceKey stateKey = new AxReferenceKey("StateParent:0.0.1:ParentName:StateName");
+        Mockito.doReturn(stateKey).when(axStateMock).getKey();
+
+        AxArtifactKey task0Key = new AxArtifactKey("Task0:0.0.1");
+        Mockito.doReturn(task0Key).when(axStateMock).getDefaultTask();
+        
+        Map<AxArtifactKey, Object> taskReferences = new LinkedHashMap<>();;
+        taskReferences.put(task0Key, null);
+        Mockito.doReturn(taskReferences).when(axStateMock).getTaskReferences();
+
+        AxTasks tasks = new AxTasks();
+        tasks.getTaskMap().put(task0Key, axTaskMock);
+        
+        ModelService.registerModel(AxTasks.class, tasks);
+        Mockito.doReturn(task0Key).when(axTaskMock).getKey();
+    }
+
+    @Test
+    public void testAxStateFacade() {
+        AxStateFacade stateFacade = new AxStateFacade(axStateMock);
+        
+        assertEquals("StateName", stateFacade.getStateName());
+        assertEquals("StateParent:0.0.1:ParentName:StateName", stateFacade.getId());
+        
+        assertEquals("Task0", stateFacade.getDefaultTaskKey().getName());
+        assertNull(stateFacade.getTaskKey(null));
+        assertEquals("Task0", stateFacade.getTaskKey("Task0").getName());
+        stateFacade.getTaskNames();
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java
new file mode 100644
index 000000000..a18718cc5
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/AxTaskFacadeTest.java
@@ -0,0 +1,155 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.parameters.ContextParameterConstants;
+import org.onap.policy.apex.context.parameters.SchemaParameters;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.service.ModelService;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchemas;
+import org.onap.policy.apex.model.eventmodel.concepts.AxInputField;
+import org.onap.policy.apex.model.eventmodel.concepts.AxOutputField;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.common.parameters.ParameterService;
+
+/**
+ * Test the state facade.
+ */
+public class AxTaskFacadeTest {
+    @Mock
+    private AxTask axTaskMock;
+
+    @Mock
+    private AxInputField axInputFieldMock;
+
+    @Mock
+    private AxInputField axInputFieldBadMock;
+
+    @Mock
+    private AxOutputField axOutputFieldMock;
+
+    @Mock
+    private AxOutputField axOutputFieldBadMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        AxContextSchemas schemas = new AxContextSchemas();
+
+        AxArtifactKey stringTypeKey = new AxArtifactKey("StringType:0.0.1");
+        AxContextSchema stringType = new AxContextSchema(stringTypeKey, "Java", "java.lang.String");
+        schemas.getSchemasMap().put(stringTypeKey, stringType);
+
+        ModelService.registerModel(AxContextSchemas.class, schemas);
+
+        MockitoAnnotations.initMocks(this);
+
+        AxArtifactKey task0Key = new AxArtifactKey("Task0:0.0.1");
+        Mockito.doReturn(task0Key).when(axTaskMock).getKey();
+        Mockito.doReturn(task0Key.getId()).when(axTaskMock).getId();
+
+        Map<String, AxInputField> inFieldMap = new LinkedHashMap<>();
+        Map<String, AxOutputField> outFieldMap = new LinkedHashMap<>();
+
+        inFieldMap.put("InField0", axInputFieldMock);
+        inFieldMap.put("InFieldBad", axInputFieldBadMock);
+        outFieldMap.put("OutField0", axOutputFieldMock);
+        outFieldMap.put("OutFieldBad", axOutputFieldBadMock);
+
+        Mockito.doReturn(inFieldMap).when(axTaskMock).getInputFields();
+        Mockito.doReturn(outFieldMap).when(axTaskMock).getOutputFields();
+
+        Mockito.doReturn(new AxReferenceKey(task0Key, "InField0")).when(axInputFieldMock).getKey();
+        Mockito.doReturn(stringTypeKey).when(axInputFieldMock).getSchema();
+
+        Mockito.doReturn(new AxReferenceKey(task0Key, "OutField0")).when(axOutputFieldMock).getKey();
+        Mockito.doReturn(stringTypeKey).when(axOutputFieldMock).getSchema();
+
+        ParameterService.register(new SchemaParameters());
+    }
+
+    @After
+    public void teardown() {
+        ParameterService.deregister(ContextParameterConstants.SCHEMA_GROUP_NAME);
+        ModelService.clear();
+    }
+
+    @Test
+    public void testAxStateFacade() {
+        AxTaskFacade taskFacade = new AxTaskFacade(axTaskMock);
+
+        assertEquals("Task0", taskFacade.getTaskName());
+        assertEquals("Task0:0.0.1", taskFacade.getId());
+
+        try {
+            taskFacade.getInFieldSchemaHelper("InFieldDoesntExist");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("no incoming field with name \"InFieldDoesntExist\" " + "defined on task \"Task0:0.0.1\"",
+                            exc.getMessage());
+        }
+
+        try {
+            taskFacade.getOutFieldSchemaHelper("OutFieldDoesntExist");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("no outgoing field with name \"OutFieldDoesntExist\" " + "defined on task \"Task0:0.0.1\"",
+                            exc.getMessage());
+        }
+
+        assertNotNull(taskFacade.getInFieldSchemaHelper("InField0"));
+        assertNotNull(taskFacade.getOutFieldSchemaHelper("OutField0"));
+
+        try {
+            taskFacade.getInFieldSchemaHelper("InFieldBad");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("schema helper cannot be created for task field \"InFieldBad\" "
+                            + "with key \"null\" with schema \"null\"", exc.getMessage());
+        }
+
+        try {
+            taskFacade.getOutFieldSchemaHelper("OutFieldBad");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("schema helper cannot be created for task field \"OutFieldBad\" "
+                            + "with key \"null\" with schema \"null\"", exc.getMessage());
+        }
+
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java
new file mode 100644
index 000000000..5d5583ff6
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/DummyContextAlbum.java
@@ -0,0 +1,281 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.lang3.NotImplementedException;
+import org.onap.policy.apex.context.ContextAlbum;
+import org.onap.policy.apex.context.ContextException;
+import org.onap.policy.apex.context.SchemaHelper;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxConcept;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+
+/**
+ * Dummy context album for testing.
+ */
+public class DummyContextAlbum implements ContextAlbum {
+    private final AxArtifactKey key;
+
+    /**
+     * Constructor.
+     * @param key the key
+     */
+    public DummyContextAlbum(AxArtifactKey key) {
+        super();
+        this.key = key;
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#clear()
+     */
+    @Override
+    public void clear() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+    
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#containsKey(java.lang.Object)
+     */
+    @Override
+    public boolean containsKey(Object key) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#containsValue(java.lang.Object)
+     */
+    @Override
+    public boolean containsValue(Object value) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#entrySet()
+     */
+    @Override
+    public Set<Entry<String, Object>> entrySet() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#get(java.lang.Object)
+     */
+    @Override
+    public Object get(Object key) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#isEmpty()
+     */
+    @Override
+    public boolean isEmpty() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#keySet()
+     */
+    @Override
+    public Set<String> keySet() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#put(java.lang.Object, java.lang.Object)
+     */
+    @Override
+    public Object put(String key, Object value) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#putAll(java.util.Map)
+     */
+    @Override
+    public void putAll(Map<? extends String, ? extends Object> map) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#remove(java.lang.Object)
+     */
+    @Override
+    public Object remove(Object key) {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#size()
+     */
+    @Override
+    public int size() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Map#values()
+     */
+    @Override
+    public Collection<Object> values() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#getKey()
+     */
+    @Override
+    public AxArtifactKey getKey() {
+        return key;
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#getName()
+     */
+    @Override
+    public String getName() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#getAlbumDefinition()
+     */
+    @Override
+    public AxContextAlbum getAlbumDefinition() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#getSchemaHelper()
+     */
+    @Override
+    public SchemaHelper getSchemaHelper() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#lockForReading(java.lang.String)
+     */
+    @Override
+    public void lockForReading(String key) throws ContextException {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#lockForWriting(java.lang.String)
+     */
+    @Override
+    public void lockForWriting(String key) throws ContextException {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#unlockForReading(java.lang.String)
+     */
+    @Override
+    public void unlockForReading(String key) throws ContextException {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#unlockForWriting(java.lang.String)
+     */
+    @Override
+    public void unlockForWriting(String key) throws ContextException {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#getUserArtifactStack()
+     */
+    @Override
+    public AxConcept[] getUserArtifactStack() {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * org.onap.policy.apex.context.ContextAlbum#setUserArtifactStack(org.onap.policy.apex.model.basicmodel.concepts.
+     * AxConcept[])
+     */
+    @Override
+    public void setUserArtifactStack(AxConcept[] userArtifactStack) {
+        // Do nothing
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.onap.policy.apex.context.ContextAlbum#flush()
+     */
+    @Override
+    public void flush() throws ContextException {
+        throw new NotImplementedException("Not implemented on dummy class");
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java
new file mode 100644
index 000000000..8b0710ec7
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/StateFinalizerExecutionContextTest.java
@@ -0,0 +1,113 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.ContextAlbum;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.executor.StateFinalizerExecutor;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+
+/**
+ * Test Task Execution Context.
+ */
+public class StateFinalizerExecutionContextTest {
+    @Mock
+    private StateFinalizerExecutor stateFinalizerExecutorMock;
+
+    @Mock
+    private StateFinalizerExecutor parentExecutorMock;
+
+    @Mock
+    private AxState axStateMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey1:0.0.1")));
+
+        Mockito.doReturn(contextAlbumReferences).when(axStateMock).getContextAlbumReferences();
+        Mockito.doReturn(new AxReferenceKey("Parent:0.0.1:ParentName:StateName")).when(axStateMock).getKey();
+
+        Map<AxArtifactKey, ContextAlbum> contextAlbumMap = new LinkedHashMap<>();
+        AxArtifactKey album0Key = new AxArtifactKey("AlbumKey0:0.0.1");
+        AxArtifactKey album1Key = new AxArtifactKey("AlbumKey1:0.0.1");
+
+        contextAlbumMap.put(album0Key, new DummyContextAlbum(album0Key));
+        contextAlbumMap.put(album1Key, new DummyContextAlbum(album1Key));
+
+        Mockito.doReturn(contextAlbumMap).when(internalContextMock).getContextAlbums();
+
+        Mockito.doReturn(parentExecutorMock).when(stateFinalizerExecutorMock).getParent();
+        Mockito.doReturn(new AxReferenceKey("Parent:0.0.1:ParentName:LocalName")).when(parentExecutorMock).getKey();
+    }
+
+    @Test
+    public void test() {
+        final Map<String, Object> fields = new LinkedHashMap<>();
+        final Set<String> stateOutputNames = new LinkedHashSet<>();
+
+        StateFinalizerExecutionContext sfec = new StateFinalizerExecutionContext(stateFinalizerExecutorMock, 0,
+                        axStateMock, fields, stateOutputNames, internalContextMock);
+
+        assertNotNull(sfec);
+        sfec.setMessage("SFEC Message");
+        assertEquals("SFEC Message", sfec.getMessage());
+
+        sfec.setSelectedStateOutputName("SomeOutput");
+        assertEquals("SomeOutput", sfec.getSelectedStateOutputName());
+
+        ContextAlbum contextAlbum = sfec.getContextAlbum("AlbumKey0");
+        assertEquals("AlbumKey0:0.0.1", contextAlbum.getKey().getId());
+
+        try {
+            sfec.getContextAlbum("AlbumKeyNonExistant");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("cannot find definition of context album \"AlbumKeyNonExistant\" "
+                            + "on state \"Parent:0.0.1:ParentName:StateName\"", exc.getMessage());
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java
new file mode 100644
index 000000000..c6c196a01
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskExecutionContextTest.java
@@ -0,0 +1,108 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.ContextAlbum;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.executor.TaskExecutor;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+
+/**
+ * Test Task Execution Context.
+ */
+public class TaskExecutionContextTest {
+    @Mock
+    private TaskExecutor taskExecutorMock;
+
+    @Mock
+    private TaskExecutor parentExecutorMock;
+
+    @Mock
+    private AxTask axTaskMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey1:0.0.1")));
+
+        Mockito.doReturn(contextAlbumReferences).when(axTaskMock).getContextAlbumReferences();
+
+        Map<AxArtifactKey, ContextAlbum> contextAlbumMap = new LinkedHashMap<>();
+        AxArtifactKey album0Key = new AxArtifactKey("AlbumKey0:0.0.1");
+        AxArtifactKey album1Key = new AxArtifactKey("AlbumKey1:0.0.1");
+
+        contextAlbumMap.put(album0Key, new DummyContextAlbum(album0Key));
+        contextAlbumMap.put(album1Key, new DummyContextAlbum(album1Key));
+
+        Mockito.doReturn(contextAlbumMap).when(internalContextMock).getContextAlbums();
+
+        Mockito.doReturn(parentExecutorMock).when(taskExecutorMock).getParent();
+        Mockito.doReturn(new AxArtifactKey("Parent:0.0.1")).when(parentExecutorMock).getKey();
+    }
+
+    @Test
+    public void test() {
+        final Map<String, Object> inFields = new LinkedHashMap<>();
+        final Map<String, Object> outFields = new LinkedHashMap<>();
+
+        TaskExecutionContext tec = new TaskExecutionContext(taskExecutorMock, 0, axTaskMock, inFields, outFields,
+                        internalContextMock);
+
+        assertNotNull(tec);
+        tec.setMessage("TEC Message");
+        assertEquals("TEC Message", tec.getMessage());
+
+        ContextAlbum contextAlbum = tec.getContextAlbum("AlbumKey0");
+        assertEquals("AlbumKey0:0.0.1", contextAlbum.getKey().getId());
+
+        try {
+            tec.getContextAlbum("AlbumKeyNonExistant");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("cannot find definition of context album \"AlbumKeyNonExistant\" on task \"null\"",
+                            exc.getMessage());
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java
new file mode 100644
index 000000000..02e271717
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/context/TaskSelectionExecutionContextTest.java
@@ -0,0 +1,113 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.context;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.ContextAlbum;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.event.EnEvent;
+import org.onap.policy.apex.core.engine.executor.TaskSelectExecutor;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+
+/**
+ * Test Task Execution Context.
+ */
+public class TaskSelectionExecutionContextTest {
+    @Mock
+    private TaskSelectExecutor taskSelectExecutorMock;
+
+    @Mock
+    private TaskSelectExecutor parentExecutorMock;
+
+    @Mock
+    private AxState axStateMock;
+
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private EnEvent incomingEventMock;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        Set<AxArtifactKey> contextAlbumReferences = new LinkedHashSet<>();
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey0:0.0.1")));
+        contextAlbumReferences.add(new AxArtifactKey(("AlbumKey1:0.0.1")));
+
+        Mockito.doReturn(contextAlbumReferences).when(axStateMock).getContextAlbumReferences();
+        Mockito.doReturn(new AxReferenceKey("Parent:0.0.1:ParentName:StateName")).when(axStateMock).getKey();
+
+        Map<AxArtifactKey, ContextAlbum> contextAlbumMap = new LinkedHashMap<>();
+        AxArtifactKey album0Key = new AxArtifactKey("AlbumKey0:0.0.1");
+        AxArtifactKey album1Key = new AxArtifactKey("AlbumKey1:0.0.1");
+
+        contextAlbumMap.put(album0Key, new DummyContextAlbum(album0Key));
+        contextAlbumMap.put(album1Key, new DummyContextAlbum(album1Key));
+
+        Mockito.doReturn(contextAlbumMap).when(internalContextMock).getContextAlbums();
+
+        Mockito.doReturn(parentExecutorMock).when(taskSelectExecutorMock).getParent();
+        Mockito.doReturn(new AxReferenceKey("Parent:0.0.1:ParentName:LocalName")).when(parentExecutorMock).getKey();
+    }
+
+    @Test
+    public void test() {
+        final AxArtifactKey outgoingEventKey = new AxArtifactKey("OutEvent:0.0.1");
+
+        TaskSelectionExecutionContext tsec = new TaskSelectionExecutionContext(taskSelectExecutorMock, 0, axStateMock,
+                        incomingEventMock, outgoingEventKey, internalContextMock);
+
+        assertNotNull(tsec);
+        tsec.setMessage("TSEC Message");
+        assertEquals("TSEC Message", tsec.getMessage());
+
+        ContextAlbum contextAlbum = tsec.getContextAlbum("AlbumKey0");
+        assertEquals("AlbumKey0:0.0.1", contextAlbum.getKey().getId());
+
+        try {
+            tsec.getContextAlbum("AlbumKeyNonExistant");
+            fail("test should throw an exception");
+        } catch (Exception exc) {
+            assertEquals("cannot find definition of context album \"AlbumKeyNonExistant\" "
+                            + "on state \"Parent:0.0.1:ParentName:StateName\"", exc.getMessage());
+        }
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java
new file mode 100644
index 000000000..e77002627
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/exception/StateMachineRuntimeExceptionTest.java
@@ -0,0 +1,43 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.exception;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+/**
+ * Test state machine runtime exception.
+ *
+ */
+public class StateMachineRuntimeExceptionTest {
+
+    @Test
+    public void testException() {
+        StateMachineRuntimeException smre = new StateMachineRuntimeException("Exception Message");
+        assertEquals("Exception Message", smre.getMessage());
+        
+        smre = new StateMachineRuntimeException("Exception Message", new IOException());
+        assertEquals("Exception Message", smre.getMessage());
+    }
+}
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExceutorFactoryImplTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExceutorFactoryImplTest.java
new file mode 100644
index 000000000..7fe394758
--- /dev/null
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/executor/impl/ExceutorFactoryImplTest.java
@@ -0,0 +1,310 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.core.engine.executor.impl;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.core.engine.EngineParameters;
+import org.onap.policy.apex.core.engine.ExecutorParameters;
+import org.onap.policy.apex.core.engine.context.ApexInternalContext;
+import org.onap.policy.apex.core.engine.executor.Executor;
+import org.onap.policy.apex.core.engine.executor.exception.StateMachineException;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskSelectionLogic;
+import org.onap.policy.common.parameters.ParameterService;
+
+/**
+ * Test the executor factory implementation.
+ *
+ */
+public class ExceutorFactoryImplTest {
+    @Mock
+    private ApexInternalContext internalContextMock;
+
+    @Mock
+    private AxState stateMock;
+
+    @Mock
+    private AxTaskSelectionLogic tslMock;
+
+    @Mock
+    private AxTask taskMock;
+
+    @Mock
+    private AxTaskLogic tlMock;
+
+    @Mock
+    private AxStateFinalizerLogic sflMock;
+
+    @Mock
+    private Executor<?, ?, ?, ?> parentMock;
+
+    private ExecutorParameters executorPars;
+
+    /**
+     * Set up mocking.
+     */
+    @Before
+    public void startMocking() {
+        MockitoAnnotations.initMocks(this);
+
+        Mockito.doReturn(tslMock).when(stateMock).getTaskSelectionLogic();
+        Mockito.doReturn("Dummy").when(tslMock).getLogicFlavour();
+
+        Mockito.doReturn(tlMock).when(taskMock).getTaskLogic();
+        Mockito.doReturn("Dummy").when(tlMock).getLogicFlavour();
+
+        Mockito.doReturn("Dummy").when(sflMock).getLogicFlavour();
+    }
+
+    @After
+    public void clearPars() {
+        ParameterService.clear();
+    }
+
+    @Test
+    public void testExecutorFactoryImplGood() {
+        setGoodPars();
+
+        ExecutorFactoryImpl factory = null;
+
+        try {
+            factory = new ExecutorFactoryImpl();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        Mockito.doReturn(true).when(stateMock).checkSetTaskSelectionLogic();
+        assertNotNull(factory.getTaskSelectionExecutor(null, stateMock, internalContextMock));
+        Mockito.doReturn(false).when(stateMock).checkSetTaskSelectionLogic();
+        assertNull(factory.getTaskSelectionExecutor(null, stateMock, internalContextMock));
+
+        assertNotNull(factory.getTaskExecutor(null, taskMock, internalContextMock));
+
+        assertNotNull(factory.getStateFinalizerExecutor(parentMock, sflMock, internalContextMock));
+    }
+
+    @Test
+    public void testExecutorFactoryImplNonExistant() {
+        setNonExistantPars();
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+
+        } catch (StateMachineException ex) {
+            assertEquals("Apex executor class not found for executor plugin "
+                            + "\"org.onap.policy.apex.core.engine.executor.BadTaskExecutor\"", ex.getMessage());
+        }
+
+        executorPars.setTaskExecutorPluginClass(null);
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+        } catch (StateMachineException ex) {
+            assertEquals("Apex executor class not found for executor plugin "
+                            + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"", ex.getMessage());
+        }
+
+        executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+        } catch (StateMachineException ex) {
+            assertEquals("Apex executor class not found for executor plugin "
+                            + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"", ex.getMessage());
+        }
+
+        executorPars.setTaskSelectionExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+        } catch (StateMachineException ex) {
+            assertEquals("Apex executor class not found for executor plugin "
+                            + "\"org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor\"",
+                            ex.getMessage());
+        }
+    }
+
+    @Test
+    public void testExecutorFactoryImplBad() {
+        setBadPars();
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+
+        } catch (StateMachineException ex) {
+            assertEquals("Specified Apex executor plugin class \"java.lang.String\" "
+                            + "does not implment the Executor interface", ex.getMessage());
+        }
+
+        executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+        } catch (StateMachineException ex) {
+            assertEquals("Specified Apex executor plugin class \"java.lang.String\" "
+                            + "does not implment the Executor interface", ex.getMessage());
+        }
+
+        executorPars.setTaskSelectionExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+
+        try {
+            new ExecutorFactoryImpl();
+            fail("test should throw an exception");
+        } catch (StateMachineException ex) {
+            assertEquals("Specified Apex executor plugin class \"java.lang.String\" "
+                            + "does not implment the Executor interface", ex.getMessage());
+        }
+    }
+
+    @Test
+    public void testExecutorFactoryCreateErrors() {
+        setGoodPars();
+
+        executorPars.setTaskExecutorPluginClass(null);
+
+        ExecutorFactoryImpl factory = null;
+
+        try {
+            factory = new ExecutorFactoryImpl();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        Mockito.doReturn(true).when(stateMock).checkSetTaskSelectionLogic();
+
+        try {
+            factory.getTaskExecutor(null, taskMock, internalContextMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("Executor plugin class not defined for \"Dummy\" executor of type "
+                            + "\"org.onap.policy.apex.core.engine.executor.TaskExecutor\"", ex.getMessage());
+        }
+
+        executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor");
+
+        try {
+            factory = new ExecutorFactoryImpl();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            factory.getTaskExecutor(null, taskMock, internalContextMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("Instantiation error on \"Dummy\" executor of type "
+                            + "\"org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor\"",
+                            ex.getMessage());
+        }
+
+        executorPars.setTaskExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
+
+        try {
+            factory = new ExecutorFactoryImpl();
+        } catch (StateMachineException e) {
+            fail("test should not throw an exception");
+        }
+
+        try {
+            factory.getTaskExecutor(null, taskMock, internalContextMock);
+            fail("test should throw an exception");
+        } catch (Exception ex) {
+            assertEquals("Executor on \"Dummy\" "
+                            + "of type \"class org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor\""
+                            + " is not an instance of \"org.onap.policy.apex.core.engine.executor.TaskExecutor\"",
+                            ex.getMessage());
+        }
+    }
+
+    /**
+     * Set up good parameters.
+     */
+    private void setGoodPars() {
+        executorPars = new ExecutorParameters();
+        executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.DummyTaskExecutor");
+        executorPars.setTaskSelectionExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.DummyTaskSelectExecutor");
+        executorPars.setStateFinalizerExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.DummyStateFinalizerExecutor");
+
+        EngineParameters enginePars = new EngineParameters();
+        enginePars.getExecutorParameterMap().put("Dummy", executorPars);
+
+        ParameterService.register(enginePars);
+        ParameterService.register(executorPars);
+    }
+
+    /**
+     * Set up non existant parameters.
+     */
+    private void setNonExistantPars() {
+        executorPars = new ExecutorParameters();
+        executorPars.setTaskExecutorPluginClass("org.onap.policy.apex.core.engine.executor.BadTaskExecutor");
+        executorPars.setTaskSelectionExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor");
+        executorPars.setStateFinalizerExecutorPluginClass(
+                        "org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor");
+
+        EngineParameters enginePars = new EngineParameters();
+        enginePars.getExecutorParameterMap().put("Dummy", executorPars);
+
+        ParameterService.register(enginePars, true);
+        ParameterService.register(executorPars, true);
+    }
+
+    /**
+     * Set up bad parameters.
+     */
+    private void setBadPars() {
+        executorPars = new ExecutorParameters();
+        executorPars.setTaskExecutorPluginClass("java.lang.String");
+        executorPars.setTaskSelectionExecutorPluginClass("java.lang.String");
+        executorPars.setStateFinalizerExecutorPluginClass("java.lang.String");
+
+        EngineParameters enginePars = new EngineParameters();
+        enginePars.getExecutorParameterMap().put("Dummy", executorPars);
+
+        ParameterService.register(enginePars, true);
+        ParameterService.register(executorPars, true);
+    }
+}
diff --git a/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineServiceImplTest.java b/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineServiceImplTest.java
index 582e61948..f68a4872b 100644
--- a/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineServiceImplTest.java
+++ b/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineServiceImplTest.java
@@ -171,7 +171,13 @@ public class EngineServiceImplTest {
         esImpl.registerActionListener(null, new DummyApexEventListener());
 
         esImpl.registerActionListener("DummyListener", new DummyApexEventListener());
-        esImpl.deregisterActionListener(null);
+        try {
+            esImpl.deregisterActionListener(null);
+            fail("test should throw an exception");
+        } catch (Exception apEx) {
+            assertEquals("removeEventListener()<-Engine-0:0.0.1,STOPPED, listenerName is null", apEx.getMessage());
+        }
+            
         esImpl.deregisterActionListener("DummyListener");
 
         assertEquals(esImpl, esImpl.getEngineServiceEventInterface());
diff --git a/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineWorkerTest.java b/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineWorkerTest.java
index 5ffda6ed6..1f8052d4a 100644
--- a/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineWorkerTest.java
+++ b/services/services-engine/src/test/java/org/onap/policy/apex/service/engine/runtime/impl/EngineWorkerTest.java
@@ -143,7 +143,7 @@ public class EngineWorkerTest {
         ParameterService.deregister(ContextParameterConstants.MAIN_GROUP_NAME);
         ParameterService.deregister(EngineParameterConstants.MAIN_GROUP_NAME);
     }
-    
+
     @After
     public void cleardownTest() {
         ModelService.clear();
@@ -155,12 +155,31 @@ public class EngineWorkerTest {
 
         EngineWorker worker = new EngineWorker(new AxArtifactKey("Worker", "0.0.1"), eventQueue, atFactory);
 
-        worker.registerActionListener(null, null);
+        try {
+            worker.registerActionListener(null, null);
+            fail("test should throw an exception");
+        } catch (Exception apEx) {
+            assertEquals("addEventListener()<-Worker:0.0.1,STOPPED, listenerName is null", apEx.getMessage());
+        }
+        
         worker.registerActionListener("DummyListener", null);
-        worker.registerActionListener(null, new DummyApexEventListener());
+        
+        try {
+            worker.registerActionListener(null, new DummyApexEventListener());
+            fail("test should throw an exception");
+        } catch (Exception apEx) {
+            assertEquals("addEventListener()<-Worker:0.0.1,STOPPED, listenerName is null", apEx.getMessage());
+        }
 
         worker.registerActionListener("DummyListener", new DummyApexEventListener());
-        worker.deregisterActionListener(null);
+        
+        try {
+            worker.deregisterActionListener(null);
+            fail("test should throw an exception");
+        } catch (Exception apEx) {
+            assertEquals("removeEventListener()<-Worker:0.0.1,STOPPED, listenerName is null", apEx.getMessage());
+        }
+
         worker.deregisterActionListener("DummyListener");
 
         try {
@@ -308,7 +327,6 @@ public class EngineWorkerTest {
                             apEx.getMessage());
         }
     }
-    
 
     @Test
     public void testApexImplModelWIthModel() throws ApexException {
@@ -322,7 +340,7 @@ public class EngineWorkerTest {
         } catch (ApexException apEx) {
             fail("test should not throw an exception");
         }
-        
+
         eventQueue.add(new ApexEvent("SomeEvent", "0.0.1", "the.event.namespace", "EventSource", "EventTarget"));
 
         try {
@@ -352,7 +370,7 @@ public class EngineWorkerTest {
 
         assertEquals(AxEngineState.STOPPED, worker.getState());
         worker.startAll();
-        
+
         assertEquals(AxEngineState.READY, worker.getState());
 
         String status = worker.getStatus(worker.getEngineKeys().iterator().next());
@@ -425,7 +443,7 @@ public class EngineWorkerTest {
         } catch (ApexException apEx) {
             fail("test should not throw an exception");
         }
-        
+
         assertNotNull(worker.getApexModelKey());
     }
 }