Add junit coverage to drools-pdp

Change-Id: I253d3e85a08b893e7a9b168d92752205bcc459f6
Issue-ID: POLICY-1772
Signed-off-by: Jim Hahn <jrh3@att.com>

3 files changed, 246 insertions, 17 deletions

diff --git a/feature-simulators/src/main/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRs.java b/feature-simulators/src/main/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRs.java
index 5e7861d2..8b653aae 100644
--- a/feature-simulators/src/main/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRs.java
+++ b/feature-simulators/src/main/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRs.java
@@ -1,8 +1,8 @@
-/*
+/*-
  * ============LICENSE_START=======================================================
  * feature-simulators
  * ================================================================================
- * Copyright (C) 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright (C) 2017-2019 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.
@@ -43,14 +43,16 @@ import org.slf4j.LoggerFactory;
 
 @Path("/events")
 public class DMaaPSimulatorJaxRs {
-    private static final String NO_DATA_MSG = "No Data";
+    public static final String NO_TOPIC_MSG = "No topic";
+    public static final String NO_DATA_MSG = "No Data";
+
     private static final Map<String, BlockingQueue<String>> queues = new ConcurrentHashMap<>();
     private static final Logger logger = LoggerFactory.getLogger(DMaaPSimulatorJaxRs.class);
     private static int responseCode = 200;
 
     /**
      * Get consumer ID.
-     * 
+     *
      * @param timeout timeout value
      * @param topicName the dmaap topic
      * @param httpResponse http response object
@@ -58,7 +60,7 @@ public class DMaaPSimulatorJaxRs {
      */
     @GET
     @Path("/{topicName}/{consumeGroup}/{consumerId}")
-    public String subscribe(@DefaultValue("0") @QueryParam("timeout") int timeout, @PathParam("topicName") 
+    public String subscribe(@DefaultValue("0") @QueryParam("timeout") int timeout, @PathParam("topicName")
             String topicName, @Context final HttpServletResponse httpResponse) {
         int currentRespCode = responseCode;
         httpResponse.setStatus(currentRespCode);
@@ -79,14 +81,14 @@ public class DMaaPSimulatorJaxRs {
         else if (timeout > 0) {
             return waitForNextMessageFromQueue(timeout, topicName);
         }
-        return "No topic";
+        return NO_TOPIC_MSG;
     }
 
     private String getNextMessageFromQueue(final int timeout, final String topicName) {
         BlockingQueue<String> queue = queues.get(topicName);
         String response = NO_DATA_MSG;
         try {
-            response = queue.poll(timeout, TimeUnit.MILLISECONDS);
+            response = poll(queue, timeout);
         } catch (InterruptedException e) {
             logger.debug("error in DMaaP simulator", e);
             Thread.currentThread().interrupt();
@@ -99,7 +101,7 @@ public class DMaaPSimulatorJaxRs {
 
     private String waitForNextMessageFromQueue(int timeout, String topicName) {
         try {
-            Thread.sleep(timeout);
+            sleep(timeout);
             if (queues.containsKey(topicName)) {
                 BlockingQueue<String> queue = queues.get(topicName);
                 String response = queue.poll();
@@ -112,12 +114,12 @@ public class DMaaPSimulatorJaxRs {
             logger.debug("error in DMaaP simulator", e);
             Thread.currentThread().interrupt();
         }
-        return "No topic";
+        return NO_TOPIC_MSG;
     }
 
     /**
      * Post to a topic.
-     * 
+     *
      * @param topicName name of the topic
      * @param body message
      * @return empty string
@@ -142,12 +144,30 @@ public class DMaaPSimulatorJaxRs {
         return "Status code set";
     }
 
+    // the following non-static methods may be overridden by junit tests
+
+    protected String poll(BlockingQueue<String> queue, final int timeout) throws InterruptedException {
+        return queue.poll(timeout, TimeUnit.MILLISECONDS);
+    }
+
+    protected void sleep(int timeout) throws InterruptedException {
+        Thread.sleep(timeout);
+    }
+
     /**
      * Static method to set static response code, synchronized for multiple possible uses.
-     * 
+     *
      * @param incomingResponseCode the response code to set
      */
     private static synchronized void setResponseCode(final int incomingResponseCode) {
-        responseCode = incomingResponseCode; 
+        responseCode = incomingResponseCode;
+    }
+
+    /**
+     * Used only by junit tests to reset the simulator.
+     */
+    protected static void reset() {
+        responseCode = 200;
+        queues.clear();
     }
 }
diff --git a/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRsTest.java b/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRsTest.java
new file mode 100644
index 00000000..7200bdce
--- /dev/null
+++ b/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorJaxRsTest.java
@@ -0,0 +1,207 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * 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.simulators;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.doThrow;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.LinkedBlockingQueue;
+import javax.servlet.http.HttpServletResponse;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+public class DMaaPSimulatorJaxRsTest {
+    private static final String MESSAGE = "hello";
+    private static final String MESSAGE2 = "world";
+    private static final String EXPECTED_EXCEPTION = "expected exception";
+    private static final String TOPIC = "my-topic";
+    private static final int TIMEOUT_MS = 10;
+    private static final int LONG_TIMEOUT_MS = 250;
+
+    @Mock
+    private HttpServletResponse resp;
+
+    private DMaaPSimulatorJaxRs sim;
+
+    /**
+     * Initializes objects and creates the simulator.
+     */
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        sim = new DMaaPSimulatorJaxRs();
+    }
+
+    @After
+    public void tearDown() {
+        DMaaPSimulatorJaxRs.reset();
+    }
+
+    @Test
+    public void testSubscribe() {
+        sim.publish(TOPIC, MESSAGE);
+
+        assertEquals(MESSAGE, sim.subscribe(0, TOPIC, resp));
+    }
+
+    @Test
+    public void testSubscribe_FlushEx() throws IOException {
+        doThrow(new IOException(EXPECTED_EXCEPTION)).when(resp).flushBuffer();
+
+        assertEquals("Got an error", sim.subscribe(TIMEOUT_MS, TOPIC, resp));
+    }
+
+    @Test
+    public void testSubscribe_BadStatus_testSetResponseCode() {
+        sim.setStatus(199);
+        assertEquals("You got response code: 199", sim.subscribe(TIMEOUT_MS, TOPIC, resp));
+
+        sim.setStatus(300);
+        assertEquals("You got response code: 300", sim.subscribe(TIMEOUT_MS, TOPIC, resp));
+    }
+
+    @Test
+    public void testSubscribe_UnknownTopic_ZeroTimeout() {
+        assertEquals(DMaaPSimulatorJaxRs.NO_TOPIC_MSG, sim.subscribe(0, TOPIC, resp));
+    }
+
+    @Test
+    public void testSubscribe_UnknownTopic_NonZeroTimeout() {
+        assertEquals(DMaaPSimulatorJaxRs.NO_TOPIC_MSG, sim.subscribe(TIMEOUT_MS, TOPIC, resp));
+    }
+
+    @Test
+    public void testGetNextMessageFromQueue() {
+        sim.publish(TOPIC, MESSAGE);
+        sim.publish(TOPIC, MESSAGE2);
+
+        assertEquals(MESSAGE, sim.subscribe(0, TOPIC, resp));
+        assertEquals(MESSAGE2, sim.subscribe(0, TOPIC, resp));
+
+        // repeat - no message
+        assertEquals(DMaaPSimulatorJaxRs.NO_DATA_MSG, sim.subscribe(0, TOPIC, resp));
+    }
+
+    @Test
+    public void testGetNextMessageFromQueue_Interrupted() throws InterruptedException {
+        sim = new DMaaPSimulatorJaxRs() {
+            @Override
+            protected String poll(BlockingQueue<String> queue, int timeout) throws InterruptedException {
+                throw new InterruptedException(EXPECTED_EXCEPTION);
+            }
+        };
+
+        sim.publish(TOPIC, MESSAGE);
+
+        // put it in the background so we don't interrupt the test thread
+        BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+        backgroundSubscribe(queue);
+
+        assertEquals(DMaaPSimulatorJaxRs.NO_DATA_MSG, queue.take());
+    }
+
+    @Test
+    public void testWaitForNextMessageFromQueue() throws InterruptedException {
+        BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+
+        CountDownLatch latch1 = backgroundSubscribe(queue);
+        CountDownLatch latch2 = backgroundSubscribe(queue);
+
+        // wait for both threads to start
+        latch1.await();
+        latch2.await();
+
+        /*
+         * Must pause to prevent the topic from being created before subscribe() is
+         * invoked.
+         */
+        Thread.sleep(LONG_TIMEOUT_MS / 3);
+
+        // only publish one message
+        sim.publish(TOPIC, MESSAGE);
+
+        // wait for both subscribers to add their messages to the queue
+        List<String> messages = new ArrayList<>();
+        messages.add(queue.take());
+        messages.add(queue.take());
+
+        // sort them so the order is consistent
+        Collections.sort(messages);
+
+        assertEquals("[No Data, hello]", messages.toString());
+    }
+
+    @Test
+    public void testWaitForNextMessageFromQueue_Interrupted() throws InterruptedException {
+        sim = new DMaaPSimulatorJaxRs() {
+            @Override
+            protected void sleep(int timeout) throws InterruptedException {
+                throw new InterruptedException(EXPECTED_EXCEPTION);
+            }
+        };
+
+        // put it in the background so we don't interrupt the test thread
+        BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+        backgroundSubscribe(queue);
+
+        assertEquals(DMaaPSimulatorJaxRs.NO_TOPIC_MSG, queue.take());
+    }
+
+    @Test
+    public void testPublish() {
+        assertEquals("", sim.publish(TOPIC, MESSAGE));
+        assertEquals(MESSAGE, sim.subscribe(0, TOPIC, resp));
+    }
+
+    @Test
+    public void testSetStatus() {
+        assertEquals("Status code set", sim.setStatus(500));
+        assertEquals("You got response code: 500", sim.subscribe(TIMEOUT_MS, TOPIC, resp));
+    }
+
+    /**
+     * Invokes subscribe() in a background thread.
+     *
+     * @param queue where to place the returned result
+     * @return a latch that will be counted down just before the background thread invokes
+     *         subscribe()
+     */
+    private CountDownLatch backgroundSubscribe(BlockingQueue<String> queue) {
+        CountDownLatch latch = new CountDownLatch(1);
+
+        new Thread(() -> {
+            latch.countDown();
+            queue.add(sim.subscribe(LONG_TIMEOUT_MS, TOPIC, resp));
+        }).start();
+
+        return latch;
+    }
+}
diff --git a/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorTest.java b/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorTest.java
index 9740ac6d..bb1b1cb9 100644
--- a/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorTest.java
+++ b/feature-simulators/src/test/java/org/onap/policy/drools/simulators/DMaaPSimulatorTest.java
@@ -43,15 +43,17 @@ import org.onap.policy.drools.utils.logging.LoggerUtil;
 
 public class DMaaPSimulatorTest {
 
-    private static final int DMAAPSIM_SERVER_PORT = 6670;
+    private static int DMAAPSIM_SERVER_PORT;
 
     /**
      * Setup the simulator.
+     * @throws IOException if a server port cannot be allocated
      */
     @BeforeClass
-    public static void setUpSimulator() {
+    public static void setUpSimulator() throws IOException {
         LoggerUtil.setLevel("ROOT", "INFO");
         LoggerUtil.setLevel("org.eclipse.jetty", "WARN");
+        DMAAPSIM_SERVER_PORT = NetworkUtil.allocPort();
         try {
             final HttpServletServer testServer = HttpServletServerFactoryInstance.getServerFactory().build("dmaapSim",
                             "localhost", DMAAPSIM_SERVER_PORT, "/", false, true);
@@ -76,7 +78,7 @@ public class DMaaPSimulatorTest {
         Pair<Integer, String> response = dmaapGet("myTopicNoData", timeout);
         assertNotNull(response);
         assertNotNull(response.first);
-        assertEquals("No topic", response.second);
+        assertEquals(DMaaPSimulatorJaxRs.NO_TOPIC_MSG, response.second);
     }
 
     @Test
@@ -148,7 +150,7 @@ public class DMaaPSimulatorTest {
         response = dmaapGet(topics[1], 1000);
         assertNotNull(response);
         assertNotNull(response.first);
-        assertEquals("No topic", response.second);
+        assertEquals(DMaaPSimulatorJaxRs.NO_TOPIC_MSG, response.second);
 
         response = dmaapPost(topics[1], data[1][0]);
         assertNotNull(response);
@@ -183,7 +185,7 @@ public class DMaaPSimulatorTest {
         response = dmaapGet(topics[0], 1000);
         assertNotNull(response);
         assertNotNull(response.first);
-        assertEquals("No Data", response.second);
+        assertEquals(DMaaPSimulatorJaxRs.NO_DATA_MSG, response.second);
     }
 
     @Test