Report each plugin once in worker heartbeats (#3150)

Author: patbeqo

CHANGELOG.md

@@ -79,6 +79,8 @@ to docs, or any other relevant information.
   behavior during replay.
 - Test server now honors retry expiration deadlines that fall exactly on a whole second. Previously such deadlines were
   ignored and retries were scheduled past them instead of failing with `RETRY_STATE_TIMEOUT`.
+- Worker heartbeats now list each plugin name once. Previously a plugin registered on both the
+  `WorkflowClient` and the `WorkerFactory` was listed twice.
 
 ## Previous releases
 

temporal-sdk/src/main/java/io/temporal/worker/Worker.java

@@ -775,10 +775,12 @@ Supplier<WorkerHeartbeat> buildHeartbeatCallback(
         hb.setTotalStickyCacheMiss(cache.getCacheMisses());
         hb.setCurrentStickyCacheSize(cache.getCurrentCacheSize());
 
-        // Plugins
-        for (WorkerPlugin plugin : plugins) {
-          hb.addPlugins(PluginInfo.newBuilder().setName(plugin.getName()).build());
-        }
+        // A plugin can be registered on both the client and the worker factory, so report each
+        // name once.
+        plugins.stream()
+            .map(WorkerPlugin::getName)
+            .distinct()
+            .forEach(name -> hb.addPlugins(PluginInfo.newBuilder().setName(name).build()));
 
         return hb.build();
       }

temporal-sdk/src/test/java/io/temporal/worker/WorkerHeartbeatPluginsTest.java

@@ -0,0 +1,49 @@
+package io.temporal.worker;
+
+import static org.junit.Assert.assertEquals;
+
+import io.temporal.api.worker.v1.PluginInfo;
+import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowClientOptions;
+import io.temporal.common.SimplePlugin;
+import io.temporal.testing.CloudTestExclusion.RequiresLocalServer;
+import io.temporal.testing.CloudTestExclusionNote;
+import io.temporal.testing.TestWorkflowEnvironment;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@CloudTestExclusionNote("This test directly creates and controls a local test service.")
+@Category(RequiresLocalServer.class)
+public class WorkerHeartbeatPluginsTest {
+
+  @Test
+  public void pluginRegisteredOnClientAndFactoryIsReportedOnce() {
+    SimplePlugin plugin = SimplePlugin.newBuilder("test-plugin").build();
+
+    try (TestWorkflowEnvironment env = TestWorkflowEnvironment.newInstance()) {
+      WorkflowClient client =
+          WorkflowClient.newInstance(
+              env.getWorkflowServiceStubs(),
+              WorkflowClientOptions.newBuilder()
+                  .setNamespace(env.getNamespace())
+                  .setPlugins(plugin)
+                  .build());
+      WorkerFactory factory =
+          WorkerFactory.newInstance(
+              client, WorkerFactoryOptions.newBuilder().setPlugins(plugin).build());
+      Worker worker = factory.newWorker("test-queue");
+      factory.start();
+
+      List<String> reportedPlugins =
+          worker.buildHeartbeatCallback("test-worker-group", null).get().getPluginsList().stream()
+              .map(PluginInfo::getName)
+              .collect(Collectors.toList());
+      assertEquals(Collections.singletonList("test-plugin"), reportedPlugins);
+
+      factory.shutdownNow();
+    }
+  }
+}