Provide a way to trigger Drools rules when an update occurs

An instance of 'DroolsInitFeature.Init' is inserted into a Drools
session when it is initialized, updated, or restored from
persistent data. This provides an opportunity to catch more
initialization scenarios than you can with an empty 'when' clause.

Updates:

1) Change 'DroolsInitFeature' to use Policy Engine scheduled executor

2) Add new test to 'DroolsInitFeatureTest' to verify that the 'Init'
   object is inserted into and deleted from Drools memory

3) Remove trailing spaces

Issue-ID: POLICY-1948
Change-Id: I4748c2415c4563e98b4a53d573c9ebe1e96e8e34
Signed-off-by: Straubs, Ralph (rs8887) <rs8887@att.com>

1 files changed, 110 insertions, 0 deletions

diff --git a/feature-drools-init/src/test/java/org/onap/policy/drools/droolsinit/DroolsInitFeatureTest.java b/feature-drools-init/src/test/java/org/onap/policy/drools/droolsinit/DroolsInitFeatureTest.java
new file mode 100644
index 00000000..36e64960
--- /dev/null
+++ b/feature-drools-init/src/test/java/org/onap/policy/drools/droolsinit/DroolsInitFeatureTest.java
@@ -0,0 +1,110 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * feature-drools-init
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.drools.droolsinit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.kie.api.runtime.KieSession;
+import org.kie.api.runtime.rule.FactHandle;
+import org.onap.policy.drools.core.PolicySession;
+import org.onap.policy.drools.system.PolicyEngineConstants;
+import org.powermock.reflect.Whitebox;
+
+public class DroolsInitFeatureTest {
+    private static final String POLICY_ENGINE_EXECUTOR_FIELD = "executorService";
+    private static ScheduledExecutorService saveExec;
+    private static PolicySession policySession;
+    private static KieSession kieSession;
+
+    private DroolsInitFeature feature;
+
+    /**
+     * Class-level initialization.
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        saveExec = Whitebox.getInternalState(PolicyEngineConstants.getManager(), POLICY_ENGINE_EXECUTOR_FIELD);
+
+        policySession = mock(PolicySession.class);
+        kieSession = mock(KieSession.class);
+        when(policySession.getKieSession()).thenReturn(kieSession);
+    }
+
+    /**
+     * Restore 'PolicyEngineConstants.manager'.
+     */
+    @AfterClass
+    public static void cleanup() {
+        Whitebox.setInternalState(PolicyEngineConstants.getManager(), POLICY_ENGINE_EXECUTOR_FIELD, saveExec);
+    }
+
+    @Before
+    public void setUp() {
+        feature = new DroolsInitFeature();
+    }
+
+    @Test
+    public void getSequenceNumberTest() {
+        assertEquals(0, feature.getSequenceNumber());
+    }
+
+    @Test
+    public void selectThreadModelTest() {
+        assertNull(feature.selectThreadModel(policySession));
+    }
+
+    @Test
+    public void initTest() {
+        FactHandle factHandle = mock(FactHandle.class);
+        when(kieSession.insert(any())).thenReturn(factHandle);
+        when(kieSession.getObject(factHandle)).thenReturn(new Object());
+
+        // dummy 'ScheduledExecutorService' -- 'schedule' runs immediately
+        ScheduledExecutorService executorService = new ScheduledThreadPoolExecutor(3) {
+            @Override
+            public ScheduledFuture<?> schedule(Runnable runnable, long delay, TimeUnit unit) {
+                runnable.run();
+                return null;
+            }
+        };
+
+        Whitebox.setInternalState(PolicyEngineConstants.getManager(), POLICY_ENGINE_EXECUTOR_FIELD, executorService);
+
+        // triggers creation of 'DroolsInitFeature.Init'
+        feature.selectThreadModel(policySession);
+
+        // prove that the 'delete' code ran
+        verify(kieSession).delete(factHandle);
+    }
+}