Support feature flags in java client

Author: demirkayaender

src/main/idls

@@ -19,6 +19,7 @@
 
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableMap;
+import com.uber.cadence.FeatureFlags;
 import com.uber.cadence.internal.metrics.NoopScope;
 import com.uber.m3.tally.Scope;
 import java.util.Map;
@@ -76,6 +77,9 @@ public class ClientOptions {
 
   private static final ClientOptions DEFAULT_INSTANCE;
 
+  /** Optional Feature flags to turn on/off some Cadence features */
+  private final FeatureFlags featureFlags;
+
   static {
     DEFAULT_INSTANCE = new Builder().build();
   }
@@ -123,6 +127,8 @@ private ClientOptions(Builder builder) {
       this.transportHeaders = ImmutableMap.of();
     }
 
+    this.featureFlags = builder.featureFlags;
+
     if (builder.headers != null) {
       this.headers = ImmutableMap.copyOf(builder.headers);
     } else {
@@ -179,6 +185,10 @@ public Map<String, String> getHeaders() {
     return headers;
   }
 
+  public FeatureFlags getFeatureFlags() {
+    return this.featureFlags;
+  }
+
   /**
    * Builder is the builder for ClientOptions.
    *
@@ -197,6 +207,7 @@ public static class Builder {
     private Scope metricsScope;
     private Map<String, String> transportHeaders;
     private Map<String, String> headers;
+    private FeatureFlags featureFlags;
 
     private Builder() {}
 
@@ -252,6 +263,22 @@ public Builder setListArchivedWorkflowRpcTimeout(long timeoutMillis) {
       return this;
     }
 
+    /**
+     * Sets the feature flags to turn on/off some Cadence features By default, all features under
+     * FeatureFlags are turned off.
+     *
+     * @param featureFlags FeatureFlags
+     */
+    public Builder setFeatureFlags(FeatureFlags featureFlags) {
+      this.featureFlags = featureFlags;
+      return this;
+    }
+
+    /** Returns the feature flags defined in ClientOptions */
+    public FeatureFlags getFeatureFlags() {
+      return this.featureFlags;
+    }
+
     /**
      * Sets the client application name.
      *

src/main/java/com/uber/cadence/serviceclient/ClientOptions.java

@@ -18,6 +18,8 @@
 package com.uber.cadence.serviceclient;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
 import com.uber.cadence.BadRequestError;
 import com.uber.cadence.ClientVersionNotSupportedError;
 import com.uber.cadence.ClusterInfo;
@@ -203,6 +205,13 @@ private static Map<String, String> getThriftHeaders(ClientOptions options) {
       }
     }
 
+    if (options.getFeatureFlags() != null) {
+      GsonBuilder gsonBuilder = new GsonBuilder();
+      Gson gson = gsonBuilder.create();
+      String serialized = gson.toJson(options.getFeatureFlags());
+      builder.put("cadence-client-feature-flags", serialized);
+    }
+
     return builder.build();
   }
 

src/main/java/com/uber/cadence/serviceclient/WorkflowServiceTChannel.java

@@ -35,6 +35,7 @@
 import com.uber.cadence.DomainAlreadyExistsError;
 import com.uber.cadence.DomainNotActiveError;
 import com.uber.cadence.EntityNotExistsError;
+import com.uber.cadence.FeatureFlags;
 import com.uber.cadence.GetWorkflowExecutionHistoryResponse;
 import com.uber.cadence.HistoryEvent;
 import com.uber.cadence.Memo;
@@ -205,7 +206,11 @@ protected void failed(Throwable e, Description description) {
   private ScheduledExecutorService scheduledExecutor;
   private List<ScheduledFuture<?>> delayedCallbacks = new ArrayList<>();
   private static final IWorkflowService service =
-      new WorkflowServiceTChannel(ClientOptions.defaultInstance());
+      new WorkflowServiceTChannel(
+          ClientOptions.newBuilder()
+              .setFeatureFlags(
+                  new FeatureFlags().setWorkflowExecutionAlreadyCompletedErrorEnabled(true))
+              .build());
 
   @AfterClass
   public static void closeService() {
@@ -2500,12 +2505,7 @@ public void testSignalingCompletedWorkflow() {
       client.mySignal("Hello!");
       assert (false); // Signal call should throw an exception, so fail if it doesn't
     } catch (Exception e) {
-      if (e.getCause().getClass() != WorkflowExecutionAlreadyCompletedError.class
-          && e.getCause().getClass() != EntityNotExistsError.class // only for legacy servers
-      ) {
-        // Using assertEquals to output the actual error
-        assertEquals(WorkflowExecutionAlreadyCompletedError.class, e.getCause().getClass());
-      }
+      assertEquals(WorkflowExecutionAlreadyCompletedError.class, e.getCause().getClass());
     }
   }