Fixing multiple events issue

Author: tomasbjerre

src/main/java/se/bjurr/prnfs/listener/PrnfsPullRequestEventListener.java

@@ -1,5 +1,9 @@
 package se.bjurr.prnfs.listener;
 
+import static com.google.common.cache.CacheBuilder.newBuilder;
+import static java.lang.Boolean.FALSE;
+import static java.lang.Boolean.TRUE;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static se.bjurr.prnfs.settings.SettingsStorage.getPrnfsSettings;
 
 import org.slf4j.Logger;
@@ -13,15 +17,18 @@
 import com.atlassian.sal.api.pluginsettings.PluginSettingsFactory;
 import com.atlassian.stash.event.pull.PullRequestEvent;
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.cache.Cache;
 
 public class PrnfsPullRequestEventListener {
 
  private UrlInvoker urlInvoker = new UrlInvoker();
  private final PluginSettingsFactory pluginSettingsFactory;
  private static final Logger logger = LoggerFactory.getLogger(PrnfsPullRequestEventListener.class);
+ private static Cache<Object, Object> duplicateEventCache;
 
  public PrnfsPullRequestEventListener(PluginSettingsFactory pluginSettingsFactory) {
   this.pluginSettingsFactory = pluginSettingsFactory;
+  duplicateEventCache = newBuilder().maximumSize(1000).expireAfterWrite(50, MILLISECONDS).build();
  }
 
  @VisibleForTesting
@@ -31,6 +38,9 @@ public void setUrlInvoker(UrlInvoker urlInvoker) {
 
  @EventListener
  public void anEvent(PullRequestEvent o) {
+  if (dublicateEventBug(o)) {
+   return;
+  }
   try {
    final PrnfsSettings settings = getPrnfsSettings(pluginSettingsFactory.createGlobalSettings());
    for (final PrnfsNotification n : settings.getNotifications()) {
@@ -42,4 +52,16 @@ public void anEvent(PullRequestEvent o) {
    logger.error("", e);
   }
  }
+
+ /**
+  * Looks like there is a bug in Stash that causes events to be fired twice.
+  */
+ public static boolean dublicateEventBug(PullRequestEvent o) {
+  final String footprint = o.getPullRequest().getId() + "_" + o.getAction().name();
+  if (duplicateEventCache.asMap().containsKey(footprint)) {
+   return TRUE;
+  }
+  duplicateEventCache.put(footprint, TRUE);
+  return FALSE;
+ }
 }

src/test/java/se/bjurr/prnfs/admin/PrnfsPullRequestEventListenerTest.java

@@ -1,11 +1,17 @@
 package se.bjurr.prnfs.admin;
 
+import static com.atlassian.stash.pull.PullRequestAction.APPROVED;
 import static com.atlassian.stash.pull.PullRequestAction.MERGED;
 import static com.atlassian.stash.pull.PullRequestAction.OPENED;
+import static java.lang.Boolean.FALSE;
+import static java.lang.Boolean.TRUE;
+import static java.lang.Thread.sleep;
+import static org.junit.Assert.assertEquals;
 import static se.bjurr.prnfs.admin.utils.NotificationBuilder.notificationBuilder;
 import static se.bjurr.prnfs.admin.utils.PrnfsTestBuilder.prnfsTestBuilder;
 import static se.bjurr.prnfs.admin.utils.PullRequestEventBuilder.pullRequestEventBuilder;
 import static se.bjurr.prnfs.admin.utils.PullRequestRefBuilder.pullRequestRefBuilder;
+import static se.bjurr.prnfs.listener.PrnfsPullRequestEventListener.dublicateEventBug;
 
 import org.junit.Test;
 import org.slf4j.Logger;
@@ -91,4 +97,18 @@ public void testThatMultipleUrlsCanBeInvoked() {
       .withToRef(pullRequestRefBuilder()) //
       .withId(10L).withPullRequestAction(MERGED).build()).invokedOnlyUrl("http://merged.se/");
  }
+
+ @Test
+ public void testThatDuplicateEventsFiredInStashAreIgnored() throws InterruptedException {
+  assertEquals(FALSE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(APPROVED).build()));
+  assertEquals(TRUE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(APPROVED).build()));
+  assertEquals(FALSE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(OPENED).build()));
+  assertEquals(FALSE, dublicateEventBug(pullRequestEventBuilder().withId(101L).withPullRequestAction(APPROVED).build()));
+  assertEquals(TRUE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(OPENED).build()));
+  assertEquals(TRUE, dublicateEventBug(pullRequestEventBuilder().withId(101L).withPullRequestAction(APPROVED).build()));
+  sleep(20);
+  assertEquals(TRUE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(APPROVED).build()));
+  sleep(100);
+  assertEquals(FALSE, dublicateEventBug(pullRequestEventBuilder().withId(100L).withPullRequestAction(APPROVED).build()));
+ }
 }