Bug fixes in models simulators

Fixed these issues:
- topics weren't started
- appc topics were reversed
- prevent appc simulator from responding to a response (i.e., infinite
  loop)

Issue-ID: POLICY-2434
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I1f43be72d35f874fec98f48f1a112c055c00eee5

5 files changed, 55 insertions, 3 deletions

diff --git a/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/AppcLegacyTopicServer.java b/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/AppcLegacyTopicServer.java
index 5ebd3bd2a..0c259783d 100644
--- a/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/AppcLegacyTopicServer.java
+++ b/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/AppcLegacyTopicServer.java
@@ -36,6 +36,15 @@ public class AppcLegacyTopicServer extends TopicServer<Request> {
 
     @Override
     protected String process(Request request) {
+        /*
+         * The request and response are on the same topic, thus this may be invoked with a
+         * request or with a response object. If the "action" is null, then we know it's a
+         * response.
+         */
+        if (request.getAction() == null) {
+            return null;
+        }
+
         String response = ResourceUtils.getResourceAsString("org/onap/policy/simulators/appc/appc.legacy.success.json");
         return response.replace("${replaceMe}", request.getCommonHeader().getSubRequestId());
     }
diff --git a/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/TopicServer.java b/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/TopicServer.java
index 0abe5f421..4c01511da 100644
--- a/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/TopicServer.java
+++ b/models-interactions/model-simulators/src/main/java/org/onap/policy/simulators/TopicServer.java
@@ -65,8 +65,17 @@ public abstract class TopicServer<Q> implements TopicListener {
             throw new IllegalArgumentException("cannot decode request from " + source.getTopic());
         }
 
-        sink.send(process(req));
+        String resp = process(req);
+        if (resp != null) {
+            sink.send(resp);
+        }
     }
 
+    /**
+     * Processes a request.
+     *
+     * @param request request to be processed
+     * @return the response, or {@code null} if no response is to be sent
+     */
     protected abstract String process(Q request);
 }
diff --git a/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/AppcLegacyTopicServerTest.java b/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/AppcLegacyTopicServerTest.java
index 57d574a0b..c3c3195df 100644
--- a/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/AppcLegacyTopicServerTest.java
+++ b/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/AppcLegacyTopicServerTest.java
@@ -22,6 +22,8 @@ package org.onap.policy.simulators;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertNotNull;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 
 import org.junit.Before;
@@ -55,7 +57,7 @@ public class AppcLegacyTopicServerTest {
     }
 
     @Test
-    public void testProcessAppcLcmDmaapWrapper() {
+    public void testProcess() {
         String request = ResourceUtils.getResourceAsString("org/onap/policy/simulators/appc/appc.legacy.request.json");
         assertNotNull(request);
 
@@ -66,4 +68,18 @@ public class AppcLegacyTopicServerTest {
 
         assertThat(respCaptor.getValue()).contains("111be3d2").doesNotContain("replaceMe");
     }
+
+    /**
+     * Tests process() when the message is a response.
+     */
+    @Test
+    public void testProcessNoResponse() {
+        // NOTE: this json file is a RESPONSE, not a request
+        String request = ResourceUtils.getResourceAsString("org/onap/policy/simulators/appc/appc.legacy.success.json");
+        assertNotNull(request);
+
+        server.onTopicEvent(CommInfrastructure.NOOP, MY_TOPIC, request);
+
+        verify(sink, never()).send(any());
+    }
 }
diff --git a/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/TopicServerTest.java b/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/TopicServerTest.java
index 6e176423e..11a5e3f81 100644
--- a/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/TopicServerTest.java
+++ b/models-interactions/model-simulators/src/test/java/org/onap/policy/simulators/TopicServerTest.java
@@ -85,6 +85,23 @@ public class TopicServerTest {
         verify(sink, never()).send(any());
     }
 
+    /**
+     * Tests onTopicEvent() when there is no response.
+     */
+    @Test
+    public void testOnTopicEventNoResponse() {
+        server = new MyServer() {
+            @Override
+            protected String process(MyRequest request) {
+                return null;
+            }
+        };
+
+        server.onTopicEvent(CommInfrastructure.NOOP, MY_TOPIC, "{\"text\": \"bye-bye\"}");
+
+        verify(sink, never()).send(any());
+    }
+
 
     private class MyRequest {
         private String text;
diff --git a/models-interactions/model-simulators/src/test/resources/org/onap/policy/simulators/appc/appc.legacy.request.json b/models-interactions/model-simulators/src/test/resources/org/onap/policy/simulators/appc/appc.legacy.request.json
index 8b3b73a88..61c2647cd 100644
--- a/models-interactions/model-simulators/src/test/resources/org/onap/policy/simulators/appc/appc.legacy.request.json
+++ b/models-interactions/model-simulators/src/test/resources/org/onap/policy/simulators/appc/appc.legacy.request.json
@@ -6,5 +6,6 @@
         "SubRequestID": "111be3d2-6c12-4f4b-a3e7-c349acced200",
         "RequestTrack": [],
         "Flags": []
-    }
+    },
+    "Action": "ModifyConfig"
 }