Replace try/catch with assertj - apex-pdp

Replaced try/catch blocks apex-pdp with assertj assertions. Part III of
changes.

Issue-ID: POLICY-2451
Change-Id: I77ee4140cdfc2066f463459f92163677c3e34ef2
Signed-off-by: waynedunican <wayne.dunican@est.tech>

12 files changed, 264 insertions, 722 deletions

diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
index 3d0d377bf..19828f6e2 100644
--- a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/context/ApexInternalContextTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2019 Nordix Foundation.
+ *  Modifications Copyright (C) 2019-2020 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,6 @@ package org.onap.policy.apex.core.engine.context;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
 
 import org.junit.After;
 import org.junit.Before;
@@ -128,13 +127,8 @@ public class ApexInternalContextTest {
 
     @Test
     public void testAlbumInit() throws ContextException {
-        try {
-            new ApexInternalContext(null);
-            fail("test should throw an exception");
-        } catch (ContextException ce) {
-            assertEquals("internal context update failed, supplied model is null", ce.getMessage());
-        }
-
+        assertThatThrownBy(() -> new ApexInternalContext(null))
+            .hasMessage("internal context update failed, supplied model is null");
         ApexInternalContext context = new ApexInternalContext(policyModel);
 
         assertEquals(policyModel.getKey(), context.getKey());
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
index b066e45c1..e539750e6 100644
--- 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
@@ -28,7 +28,6 @@ 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;
@@ -175,10 +174,10 @@ public class ApexEngineImplTest {
         assertNotNull(engine);
         assertEquals(engineKey, engine.getKey());
 
-        assertThatThrownBy(() -> engine.start()).hasMessage("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
+        assertThatThrownBy(engine::start).hasMessage("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
                             + "engine has not been initialized, its model is not loaded");
 
-        assertThatThrownBy(() -> engine.stop())
+        assertThatThrownBy(engine::stop)
             .hasMessage("stop()<-Engine:0.0.1,STOPPED, cannot stop engine, " + "engine is already stopped");
 
         assertEquals(AxEngineState.STOPPED, engine.getState());
@@ -222,10 +221,10 @@ public class ApexEngineImplTest {
         engine.start();
         assertEquals(AxEngineState.READY, engine.getState());
 
-        assertThatThrownBy(() -> engine.start())
+        assertThatThrownBy(engine::start)
             .hasMessage("start()<-Engine:0.0.1,READY, cannot start engine, engine not in state STOPPED");
 
-        assertThatThrownBy(() -> engine.clear())
+        assertThatThrownBy(engine::clear)
             .hasMessage("clear()<-Engine:0.0.1,READY, cannot clear engine, engine is not stopped");
 
         engine.stop();
@@ -234,7 +233,7 @@ public class ApexEngineImplTest {
         engine.clear();
         assertEquals(AxEngineState.STOPPED, engine.getState());
 
-        assertThatThrownBy(() -> engine.start()).hasMessage("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
+        assertThatThrownBy(engine::start).hasMessage("start()<-Engine:0.0.1,STOPPED,  cannot start engine, "
             + "engine has not been initialized, its model is not loaded");
 
         engine.updateModel(policyModel, false);
@@ -320,19 +319,11 @@ public class ApexEngineImplTest {
         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");
-        }
+        engine.stop();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
 
-        try {
-            engine.start();
-            assertEquals(AxEngineState.READY, engine.getState());
-        } catch (ApexException ae) {
-            fail("test should not throw an exception");
-        }
+        engine.start();
+        assertEquals(AxEngineState.READY, engine.getState());
 
         // 4 seconds is more than the 3 second wait on engine stopping
         slowListener.setWaitTime(4000);
@@ -346,20 +337,11 @@ public class ApexEngineImplTest {
 
         await().atLeast(50, TimeUnit.MILLISECONDS).until(() -> engine.getState().equals(AxEngineState.EXECUTING));
         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");
-        }
+        assertThatThrownBy(engine::stop)
+            .hasMessage("stop()<-Engine:0.0.1,STOPPED, error stopping engine, engine stop timed out");
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+        engine.clear();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
     }
 
     @Test
@@ -390,32 +372,16 @@ public class ApexEngineImplTest {
         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());
-        }
-
+        engine.stop();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+        Mockito.doThrow(new StateMachineException("mocked state machine exception",
+                new IOException("nexted exception"))).when(smHandlerMock).start();
+        assertThatThrownBy(engine::start).hasMessage("updateModel()<-Engine:0.0.1, error starting the engine state "
+                + "machines \"Engine:0.0.1\"");
         assertEquals(AxEngineState.STOPPED, engine.getState());
 
-        try {
-            engine.clear();
-            assertEquals(AxEngineState.STOPPED, engine.getState());
-        } catch (ApexException e) {
-            fail("test should not throw an exception");
-        }
+        engine.clear();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
     }
 
     @Test
@@ -463,54 +429,28 @@ public class ApexEngineImplTest {
         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());
-        }
+        ApexInternalContext internalContext = new ApexInternalContext(policyModelWithStates);
+        assertThatThrownBy(() -> dummyExecutor.setContext(null, null, internalContext))
+            .isInstanceOf(NullPointerException.class);
+
+        engine.stop();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
 
+        assertThatThrownBy(engine::start).hasMessageContaining("updateModel()<-Engine:0.0.1, error starting the "
+                    + "engine state machines \"Engine:0.0.1\"");
         assertEquals(AxEngineState.STOPPED, engine.getState());
 
-        try {
-            engine.start();
-            assertEquals(AxEngineState.READY, engine.getState());
-        } catch (ApexException ae) {
-            fail("test should not throw an exception");
-        }
+        engine.start();
+        assertEquals(AxEngineState.READY, engine.getState());
 
         // 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");
-        }
+        engine.stop();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
+
+        engine.clear();
+        assertEquals(AxEngineState.STOPPED, engine.getState());
     }
 }
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
index 225e1853f..6ac0d2e33 100644
--- a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnEventTest.java
@@ -1,7 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2020 Nordix Foundation.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,12 +21,12 @@
 
 package org.onap.policy.apex.core.engine.event;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 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.util.HashMap;
 import java.util.LinkedHashMap;
@@ -34,7 +34,6 @@ import java.util.Map;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.onap.policy.apex.context.ContextRuntimeException;
 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;
@@ -75,20 +74,10 @@ public class EnEventTest {
     @Test
     public void testEnEvent() {
         AxArtifactKey eventKey = new AxArtifactKey("Event:0.0.1");
-        try {
-            new EnEvent(eventKey);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("event definition is null or was not found in model service", ee.getMessage());
-        }
-
-        try {
-            new EnEvent((AxEvent) null);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("event definition is null or was not found in model service", ee.getMessage());
-        }
-
+        assertThatThrownBy(() -> new EnEvent(eventKey))
+            .hasMessage("event definition is null or was not found in model service");
+        assertThatThrownBy(() -> new EnEvent((AxEvent) null))
+            .hasMessage("event definition is null or was not found in model service");
         AxEvent axEvent = new AxEvent(eventKey, "a.name.space", "some source", "some target");
         ModelService.getModel(AxEvents.class).getEventMap().put(eventKey, axEvent);
 
@@ -108,20 +97,10 @@ public class EnEventTest {
         assertEquals("EnEvent [axEvent=AxEvent:(key=AxArtifactKey:(name=Event,version=0.0.1),nameSpace=a.name.space,"
                         + "source=some source,target=some target,parameter={}), "
                         + "userArtifactStack=[AxArtifactKey:(name=Event,version=0.0.1)], map={}]", event.toString());
-        try {
-            event.put(null, null);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("null keys are illegal on method parameter \"key\"", ee.getMessage());
-        }
-
-        try {
-            event.put("NonField", null);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("parameter with key \"NonField\" not defined on event \"Event\"", ee.getMessage());
-        }
-
+        assertThatThrownBy(() -> event.put(null, null))
+            .hasMessage("null keys are illegal on method parameter \"key\"");
+        assertThatThrownBy(() -> event.put("NonField", null))
+            .hasMessage("parameter with key \"NonField\" not defined on event \"Event\"");
         AxReferenceKey fieldKey = new AxReferenceKey("Parent", "0.0.1", "MyParent", "MyField");
         AxArtifactKey fieldSchemaKey = new AxArtifactKey("FieldSchema:0.0.1");
         AxField axField = new AxField(fieldKey, fieldSchemaKey);
@@ -137,21 +116,12 @@ public class EnEventTest {
         parameterMap.put("MyField", axField);
         ModelService.getModel(AxEvents.class).get(eventKey).setParameterMap(parameterMap);
 
-        try {
-            event.put("MyField", null);
-        } catch (ContextRuntimeException cre) {
-            fail("test should throw an exception here");
-        }
+        event.put("MyField", null);
         assertNull(event.get("MyField"));
 
-        try {
-            event.put("MyField", "Hello");
-            fail("test should throw an exception here");
-        } catch (ContextRuntimeException cre) {
-            assertEquals("Parent:0.0.1:MyParent:MyField: object \"Hello\" of class \"java.lang.String\" "
-                            + "not compatible with class \"java.lang.Integer\"", cre.getMessage());
-        }
-
+        assertThatThrownBy(() -> event.put("MyField", "Hello"))
+            .hasMessage("Parent:0.0.1:MyParent:MyField: object \"Hello\" of class \"java.lang.String\" "
+                            + "not compatible with class \"java.lang.Integer\"");
         event.put("MyField", 123);
         assertEquals(123, event.get("MyField"));
 
@@ -161,34 +131,14 @@ public class EnEventTest {
 
         event.putAll(event);
 
-        try {
-            event.get(null);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("null values are illegal on method parameter \"key\"", ee.getMessage());
-        }
-
-        try {
-            event.get("NonField");
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("parameter with key NonField not defined on this event", ee.getMessage());
-        }
-
-        try {
-            event.remove(null);
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("null keys are illegal on method parameter \"key\"", ee.getMessage());
-        }
-
-        try {
-            event.remove("NonField");
-            fail("test should throw an exception here");
-        } catch (EnException ee) {
-            assertEquals("parameter with key NonField not defined on this event", ee.getMessage());
-        }
-
+        assertThatThrownBy(() -> event.get(null))
+            .hasMessage("null values are illegal on method parameter \"key\"");
+        assertThatThrownBy(() -> event.get("NonField"))
+            .hasMessage("parameter with key NonField not defined on this event");
+        assertThatThrownBy(() -> event.remove(null))
+            .hasMessage("null keys are illegal on method parameter \"key\"");
+        assertThatThrownBy(() -> event.remove("NonField"))
+            .hasMessage("parameter with key NonField not defined on this event");
         event.remove("MyField");
         assertNull(event.get("MyField"));
 
diff --git a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
index 9fd26f191..168ab1d78 100644
--- a/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
+++ b/core/core-engine/src/test/java/org/onap/policy/apex/core/engine/event/EnFieldTest.java
@@ -1,25 +1,27 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * 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.event;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -67,14 +69,9 @@ public class EnFieldTest {
         AxArtifactKey fieldSchemaKey = new AxArtifactKey("FieldSchema:0.0.1");
         AxField axField = new AxField(fieldKey, fieldSchemaKey);
 
-        try {
-            new EnField(axField, null);
-            fail("test should throw an exception");
-        } catch (EnException ee) {
-            assertEquals("schema helper cannot be created for parameter with key \"Parent:0.0.1:MyParent:MyField\" "
-                            + "with schema \"AxArtifactKey:(name=FieldSchema,version=0.0.1)\"", ee.getMessage());
-        }
-
+        assertThatThrownBy(() -> new EnField(axField, null))
+            .hasMessage("schema helper cannot be created for parameter with key \"Parent:0.0.1:MyParent:My"
+                            + "Field\" with schema \"AxArtifactKey:(name=FieldSchema,version=0.0.1)\"");
         AxContextSchema schema = new AxContextSchema(fieldSchemaKey, "Java", "java.lang.Integer");
         ModelService.getModel(AxContextSchemas.class).getSchemasMap().put(fieldSchemaKey, schema);
         EnField field = new EnField(axField, 123);
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
index ed5f9135c..f3e12cc1f 100644
--- 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
@@ -1,6 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,8 +21,8 @@
 
 package org.onap.policy.apex.core.engine.executor;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -79,18 +80,9 @@ public class StateExecutorTest {
         executor.setNext(null);
         assertEquals(null, executor.getNext());
 
-        try {
-            executor.executePre(0, null, 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());
-        }
+        assertThatThrownBy(() -> executor.executePre(0, null, null))
+            .hasMessage("execution pre work not implemented on class");
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessage("execution post work not implemented on class");
     }
 }
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
index 30c7403ce..8f6544497 100644
--- 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
@@ -23,7 +23,6 @@ package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
 
 import java.util.Map;
 import java.util.Properties;
@@ -32,6 +31,7 @@ import org.junit.Test;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.ContextException;
 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;
@@ -75,7 +75,7 @@ public class StateFinalizerExecutorTest {
     }
 
     @Test
-    public void testStateFinalizerExecutor() {
+    public void testStateFinalizerExecutor() throws StateMachineException, ContextException {
         DummyStateFinalizerExecutor executor = new DummyStateFinalizerExecutor();
 
         executor.setContext(parentMock, stateFinalizerLogicMock, internalContextMock);
@@ -94,112 +94,46 @@ public class StateFinalizerExecutorTest {
         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());
-        }
-
+        assertThatThrownBy(executor::cleanUp)
+            .hasMessage("cleanUp() not implemented on class");
         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());
-        }
-
+        assertThatThrownBy(executor::prepare)
+            .hasMessage("state finalizer logic cannot be null.");
         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, new Properties(), incomingEvent);
-        } catch (Exception ex) {
-            assertEquals("task input fields \"[InField0]\" are missing for task \"Task0:0.0.1\"", ex.getMessage());
-        }
+        executor.prepare();
 
+        executor.executePre(0, new Properties(), incomingEvent);
         assertThatThrownBy(() -> executor.executePre(0, null, incomingEvent))
             .hasMessageMatching("^executionProperties is marked .*on.*ull but is null$");
 
-        try {
-            executor.executePre(0, new Properties(), incomingEvent);
-        } catch (Exception e) {
-            fail("test should not throw an exception");
-        }
-
-        try {
-            executor.execute(0, new Properties(), 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.executePre(0, new Properties(), incomingEvent);
 
+        assertThatThrownBy(() -> executor.execute(0, new Properties(), incomingEvent))
+            .hasMessage("execute() not implemented on abstract StateFinalizerExecutionContext class, "
+                + "only on its subclasses");
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessage("execute-post: state finalizer logic execution failure on state \"NULL:0.0.0:"
+                + "NULL:NULL\" on finalizer logic null");
         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, new Properties(), 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, new Properties(), incomingEvent);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessage("execute-post: state finalizer logic execution failure on state \"NULL:0.0.0:"
+                + "NULL:NULL\" on finalizer logic null, user message: Execution message");
+        executor.executePre(0, new Properties(), incomingEvent);
+
+        assertThatThrownBy(() -> executor.executePost(true))
+            .hasMessage("execute-post: state finalizer logic \"null\" did not select an output state");
+        executor.executePre(0, new Properties(), incomingEvent);
 
         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, new Properties(), incomingEvent);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        assertThatThrownBy(() -> executor.executePost(true))
+            .hasMessage("execute-post: state finalizer logic \"null\" selected output state "
+                    + "\"ThisOutputDoesNotExist\" that does not exsist on state \"NULL:0.0.0:NULL:NULL\"");
+        executor.executePre(0, new Properties(), incomingEvent);
 
         executor.getExecutionContext().setSelectedStateOutputName("ValidOutput");
-        try {
-            executor.executePost(true);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.executePost(true);
+
     }
 }
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
index d968691f6..2acb57681 100644
--- 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
@@ -21,10 +21,9 @@
 
 package org.onap.policy.apex.core.engine.executor;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -34,10 +33,12 @@ import org.junit.Test;
 import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
+import org.onap.policy.apex.context.ContextException;
 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;
@@ -182,17 +183,12 @@ public class StateMachineExecutorTest {
     }
 
     @Test
-    public void testStateMachineExecutor() {
+    public void testStateMachineExecutor() throws StateMachineException, ContextException {
         StateMachineExecutor executor =
             new StateMachineExecutor(executorFactoryMock, new AxArtifactKey("OwnerKey:0.0.1"));
 
-        try {
-            executor.execute(0, null, incomingEventMock);
-            fail("test should throw an exception");
-        } catch (Exception ex) {
-            assertEquals("no states defined on state machine", ex.getMessage());
-        }
-
+        assertThatThrownBy(() -> executor.execute(0, null, incomingEventMock))
+            .hasMessage("no states defined on state machine");
         executor.setContext(null, axPolicy, internalContextMock);
         assertEquals("Policy:0.0.1", executor.getKey().getId());
         assertEquals(null, executor.getParent());
@@ -208,213 +204,109 @@ public class StateMachineExecutorTest {
         executor.setNext(null);
         assertEquals(null, executor.getNext());
 
-        try {
-            executor.executePre(0, null, 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();
-            fail("test should throw an exception");
-        } catch (Exception e) {
-            assertTrue(e instanceof NullPointerException);
-        }
-
+        assertThatThrownBy(() -> executor.executePre(0, null, null))
+            .hasMessage("execution pre work not implemented on class");
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessage("execution post work not implemented on class");
+        assertThatThrownBy(executor::prepare)
+            .isInstanceOf(NullPointerException.class);
         axPolicy.setFirstState("BadState");
         executor.setContext(null, axPolicy, internalContextMock);
-        try {
-            executor.execute(0, null, incomingEventMock);
-            fail("test should throw an exception");
-        } catch (Exception ex) {
-            assertEquals("first state not defined on state machine", ex.getMessage());
-        }
-
+        assertThatThrownBy(() -> executor.execute(0, null, incomingEventMock))
+            .hasMessage("first state not defined on state machine");
         axPolicy.setFirstState("state0");
         executor.setContext(null, axPolicy, internalContextMock);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         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, null, 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());
-        }
-
+        assertThatThrownBy(() -> executor.execute(0, null, incomingEventMock))
+            .hasMessage("state execution failed, next state \"Policy:0.0.1:PName:BadState\" not found");
         axPolicy.getStateMap().get("State1").getStateOutputs().get("stateOutput1")
             .setNextState(AxReferenceKey.getNullKey());
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         axPolicy.getStateMap().get("State1").setTrigger(new AxArtifactKey("BadTrigger:0.0.1"));
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, 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());
-        }
-
+        assertThatThrownBy(() -> executor.execute(0, null, incomingEventMock))
+            .hasMessage("incoming event \"Event1:0.0.1\" does not match trigger \"BadTrigger:0.0.1\" "
+                + "of state \"Policy:0.0.1:NULL:state1\"");
         axPolicy.getStateMap().get("State1").setTrigger(new AxArtifactKey("Event1:0.0.1"));
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         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 "
+        assertThatThrownBy(() -> executor.setContext(null, axPolicy, internalContextMock))
+            .hasMessage("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());
-        }
-
+                + "parentLocalName=state1,localName=sfl))\" on state \"Policy:0.0.1:NULL:state1\" " + "does not exist");
         axPolicy.getStateMap().get("State1").getStateFinalizerLogicMap().put("sfl", savedSfl);
         executor.setContext(null, axPolicy, internalContextMock);
 
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         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),"
+        axPolicy.getStateMap().get("State1").getTaskReferences().get(task1Key)
+            .setStateTaskOutputType(AxStateTaskOutputType.UNDEFINED);
+        assertThatThrownBy(() -> executor.setContext(null, axPolicy, internalContextMock))
+            .hasMessage("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());
-        }
-
+                + "on state \"Policy:0.0.1:NULL:state1\"");
         axPolicy.getStateMap().get("State1").getTaskReferences().get(task1Key)
             .setStateTaskOutputType(AxStateTaskOutputType.LOGIC);
         executor.setContext(null, axPolicy, internalContextMock);
 
         dummyTsle.setTaskNo(0);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        executor.execute(0, null, incomingEventMock);
 
         dummyTsle.setTaskNo(0);
         dummySfle.setReturnBad(true);
-        try {
-            executor.execute(0, null, 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());
-        }
-
+        assertThatThrownBy(() -> executor.execute(0, null, incomingEventMock))
+            .hasMessage("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\"");
         dummyTsle.setTaskNo(0);
         dummySfle.setReturnBad(false);
-        try {
-            executor.execute(0, null, incomingEventMock);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
-
-        try {
-            executor.cleanUp();
-            fail("test should throw an exception");
-        } catch (Exception ex) {
-            assertEquals("cleanUp() not implemented on class", ex.getMessage());
-        }
+        executor.execute(0, null, incomingEventMock);
+
+        assertThatThrownBy(executor::cleanUp)
+            .hasMessage("cleanUp() not implemented on class");
     }
 
     @Test
-    public void testStateOutput() {
-        StateOutput output =
+    public void testStateOutput() throws StateMachineException {
+        final 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());
-        }
-
+        assertThatThrownBy(() -> output.setEventFields(null, null))
+            .hasMessage("incomingFieldDefinitionMap may not be null");
         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());
-        }
-
+        assertThatThrownBy(() -> output.setEventFields(incomingFieldDefinitionMap, null))
+            .hasMessage("eventFieldMap may not be null");
         Map<String, Object> eventFieldMap = new LinkedHashMap<>();
-        try {
-            output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
-        } catch (Exception ex) {
-            fail("test should not throw an exception");
-        }
+        output.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
 
         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());
-        }
-
+        assertThatThrownBy(() -> output.setEventFields(incomingFieldDefinitionMap, eventFieldMap))
+            .hasMessage("field definitions and values do not match for event Event1:0.0.1\n[]\n[key]");
         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());
-        }
-
+        assertThatThrownBy(() -> output.setEventFields(incomingFieldDefinitionMap, eventFieldMap))
+            .hasMessage("field \"key\" does not exist on event \"Event1:0.0.1\"");
         incomingFieldDefinitionMap.clear();
         eventFieldMap.clear();
         AxArtifactKey stringSchemaKey = new AxArtifactKey("StringSchema:0.0.1");
@@ -422,18 +314,15 @@ public class StateMachineExecutorTest {
         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.setEventFields(incomingFieldDefinitionMap, eventFieldMap);
 
-        output = new StateOutput(axPolicy.getStateMap().get("State0").getStateOutputs().get("stateOutput0"));
+        StateOutput outputCopy = new StateOutput(axPolicy.getStateMap().get("State0")
+                .getStateOutputs().get("stateOutput0"));
 
         EnEvent incomingEvent = new EnEvent(new AxArtifactKey("Event0:0.0.1"));
-        output.copyUnsetFields(incomingEvent);
+        outputCopy.copyUnsetFields(incomingEvent);
 
         incomingEvent.put("Event1Field0", "Hello");
-        output.copyUnsetFields(incomingEvent);
+        outputCopy.copyUnsetFields(incomingEvent);
     }
 }
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
index edfbcf20f..613d1ae01 100644
--- 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
@@ -23,7 +23,6 @@ package org.onap.policy.apex.core.engine.executor;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -85,7 +84,7 @@ public class TaskSelectExecutorTest {
     }
 
     @Test
-    public void testTaskSelectionExecutor() {
+    public void testTaskSelectionExecutor() throws StateMachineException {
         DummyTaskSelectExecutor executor = new DummyTaskSelectExecutor();
 
         executor.setContext(null, axStateMock, internalContextMock);
@@ -104,102 +103,44 @@ public class TaskSelectExecutorTest {
         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());
-        }
-
+        assertThatThrownBy(executor::cleanUp)
+            .hasMessage("cleanUp() not implemented on class");
         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());
-        }
-
+        assertThatThrownBy(executor::prepare)
+            .hasMessage("task selection logic cannot be null.");
         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, new Properties(), incomingEvent);
-        } catch (Exception e) {
-            fail("test should not throw an exception");
-        }
-
-        try {
-            executor.execute(0, new Properties(), 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.prepare();
+
+        executor.executePre(0, new Properties(), incomingEvent);
+
+        assertThatThrownBy(() -> executor.execute(0, new Properties(), incomingEvent))
+            .hasMessage("execute() not implemented on class");
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessage("execute-post: task selection logic failed on state \"State0Parent:0.0.1:Parent:State0\"");
 
         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, new Properties(), 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, new Properties(), incomingEvent);
-        } catch (Exception e) {
-            fail("test should not throw an exception");
-        }
+        assertThatThrownBy(() -> executor.executePost(false))
+            .hasMessageContaining("execute-post: task selection logic failed on state \""
+                + "State0Parent:0.0.1:Parent:State0\", user message: Execution message");
+        executor.executePre(0, new Properties(), incomingEvent);
+
+        executor.executePost(true);
+        assertEquals("Task1", executor.getOutgoing().getName());
+
+        executor.executePre(0, new Properties(), incomingEvent);
 
         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, new Properties(), incomingEvent);
-        } catch (Exception e) {
-            fail("test should not throw an exception");
-        }
+        assertThatThrownBy(() -> executor.executePost(true))
+            .hasMessageContaining("task \"IDontExist:0.0.0\" returned by task selection logic not defined "
+                + "on state \"State0Parent:0.0.1:Parent:State0\"");
+        executor.executePre(0, new Properties(), incomingEvent);
 
         executor.getOutgoing().setName("Task0");
 
-        try {
-            executor.executePost(true);
-            assertEquals("Task0", executor.getOutgoing().getName());
-        } catch (Exception e) {
-            fail("test should not throw an exception");
-        }
+        executor.executePost(true);
+        assertEquals("Task0", executor.getOutgoing().getName());
 
         assertThatThrownBy(() -> executor.executePre(0, null, incomingEvent))
             .hasMessageMatching("^executionProperties is marked .*on.*ull but is null$");
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
index cfa43ecf6..8ef78efe9 100644
--- 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
@@ -1,28 +1,29 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * 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.assertj.core.api.Assertions.assertThatThrownBy;
 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;
@@ -115,40 +116,20 @@ public class AxTaskFacadeTest {
         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());
-        }
-
+        assertThatThrownBy(() -> taskFacade.getInFieldSchemaHelper("InFieldDoesntExist"))
+            .hasMessage("no incoming field with name \"InFieldDoesntExist\" " + "defined on task "
+                    + "\"Task0:0.0.1\"");
+        assertThatThrownBy(() -> taskFacade.getOutFieldSchemaHelper("OutFieldDoesntExist"))
+            .hasMessage("no outgoing field with name \"OutFieldDoesntExist\" " + "defined on task "
+                    + "\"Task0:0.0.1\"");
         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());
-        }
-
+        assertThatThrownBy(() -> taskFacade.getInFieldSchemaHelper("InFieldBad"))
+            .hasMessage("schema helper cannot be created for task field \"InFieldBad\" "
+                    + "with key \"null\" with schema \"null\"");
+        assertThatThrownBy(() -> taskFacade.getOutFieldSchemaHelper("OutFieldBad"))
+            .hasMessage("schema helper cannot be created for task field \"OutFieldBad\" "
+                    + "with key \"null\" with schema \"null\"");
     }
 }
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
index bbd86ed54..c540f51ad 100644
--- 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
@@ -1,6 +1,7 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,9 +21,9 @@
 
 package org.onap.policy.apex.core.engine.executor.context;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 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;
@@ -101,12 +102,8 @@ public class StateFinalizerExecutionContextTest {
         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());
-        }
+        assertThatThrownBy(() -> sfec.getContextAlbum("AlbumKeyNonExistant"))
+            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistant\" "
+                            + "on state \"Parent:0.0.1:ParentName:StateName\"");
     }
 }
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
index 2f8b91ecc..5857e0513 100644
--- 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
@@ -1,28 +1,29 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * 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.assertj.core.api.Assertions.assertThatThrownBy;
 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;
@@ -101,12 +102,8 @@ public class TaskSelectionExecutionContextTest {
         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());
-        }
+        assertThatThrownBy(() -> tsec.getContextAlbum("AlbumKeyNonExistant"))
+            .hasMessage("cannot find definition of context album \"AlbumKeyNonExistant\" "
+                            + "on state \"Parent:0.0.1:ParentName:StateName\"");
     }
 }
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
index 7fe394758..5957ff347 100644
--- 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
@@ -1,29 +1,29 @@
 /*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2020 Nordix Foundation
  * ================================================================================
  * 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.assertj.core.api.Assertions.assertThatThrownBy;
 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;
@@ -93,16 +93,12 @@ public class ExceutorFactoryImplTest {
     }
 
     @Test
-    public void testExecutorFactoryImplGood() {
+    public void testExecutorFactoryImplGood() throws StateMachineException {
         setGoodPars();
 
         ExecutorFactoryImpl factory = null;
 
-        try {
-            factory = new ExecutorFactoryImpl();
-        } catch (StateMachineException e) {
-            fail("test should not throw an exception");
-        }
+        factory = new ExecutorFactoryImpl();
 
         Mockito.doReturn(true).when(stateMock).checkSetTaskSelectionLogic();
         assertNotNull(factory.getTaskSelectionExecutor(null, stateMock, internalContextMock));
@@ -118,142 +114,76 @@ public class ExceutorFactoryImplTest {
     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());
-        }
-
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Apex executor class not found for executor plugin "
+                            + "\"org.onap.policy.apex.core.engine.executor.BadTaskExecutor\"");
         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());
-        }
-
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Apex executor class not found for executor plugin "
+                    + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
         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());
-        }
-
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Apex executor class not found for executor plugin "
+                    + "\"org.onap.policy.apex.core.engine.executor.BadTaskSelectExecutor\"");
         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());
-        }
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Apex executor class not found for executor plugin "
+                    + "\"org.onap.policy.apex.core.engine.executor.BadStateFinalizerExecutor\"");
     }
 
     @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());
-        }
-
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
+                    + "does not implment the Executor interface");
         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());
-        }
-
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
+                    + "does not implment the Executor interface");
         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());
-        }
+        assertThatThrownBy(() -> new ExecutorFactoryImpl())
+            .hasMessage("Specified Apex executor plugin class \"java.lang.String\" "
+                    + "does not implment the Executor interface");
     }
 
     @Test
-    public void testExecutorFactoryCreateErrors() {
+    public void testExecutorFactoryCreateErrors() throws StateMachineException {
         setGoodPars();
 
         executorPars.setTaskExecutorPluginClass(null);
 
-        ExecutorFactoryImpl factory = null;
-
-        try {
-            factory = new ExecutorFactoryImpl();
-        } catch (StateMachineException e) {
-            fail("test should not throw an exception");
-        }
+        final ExecutorFactoryImpl factory = new ExecutorFactoryImpl();
 
         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());
-        }
-
+        assertThatThrownBy(() -> factory.getTaskExecutor(null, taskMock, internalContextMock))
+            .hasMessage("Executor plugin class not defined for \"Dummy\" executor of type "
+                    + "\"org.onap.policy.apex.core.engine.executor.TaskExecutor\"");
         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());
-        }
+        ExecutorFactoryImpl factoryInitError = new ExecutorFactoryImpl();
 
+        assertThatThrownBy(() -> factoryInitError.getTaskExecutor(null, taskMock, internalContextMock))
+            .hasMessage("Instantiation error on \"Dummy\" executor of type "
+                    + "\"org.onap.policy.apex.core.engine.executor.DummyFailingTaskExecutor\"");
         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());
-        }
+        ExecutorFactoryImpl factoryDummyError = new ExecutorFactoryImpl();
+
+        assertThatThrownBy(() -> factoryDummyError.getTaskExecutor(null, taskMock, internalContextMock))
+            .hasMessage("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\"");
     }
 
     /**