fixed tests

Author: bachuv

client/src/main/java/com/microsoft/durabletask/DurableTaskGrpcClient.java

@@ -425,6 +425,10 @@ public void rewindInstance(String instanceId, @Nullable String reason) {
         try {
             this.sidecarClient.rewindInstance(rewindRequestBuilder.build());
         } catch (StatusRuntimeException e) {
+            if (e.getStatus().getCode() == Status.Code.NOT_FOUND) {
+                throw new IllegalArgumentException(
+                        "No orchestration instance with ID '" + instanceId + "' was found.", e);
+            }
             if (e.getStatus().getCode() == Status.Code.FAILED_PRECONDITION) {
                 throw new IllegalStateException(
                         "Orchestration instance '" + instanceId + "' is not in a failed state and cannot be rewound.", e);

client/src/test/java/com/microsoft/durabletask/DurableTaskGrpcClientTest.java

@@ -424,7 +424,7 @@ public void rewindInstance(RewindInstanceRequest request, StreamObserver<RewindI
     }
 
     @Test
-    void rewindInstance_notFound_throwsIllegalArgumentExceptionThroughHelper() throws IOException {
+    void rewindInstance_notFound_throwsIllegalArgumentExceptionWithCustomMessage() throws IOException {
         DurableTaskClient client = createClientWithFakeService(new TaskHubSidecarServiceGrpc.TaskHubSidecarServiceImplBase() {
             @Override
             public void rewindInstance(RewindInstanceRequest request, StreamObserver<RewindInstanceResponse> responseObserver) {
@@ -437,8 +437,9 @@ public void rewindInstance(RewindInstanceRequest request, StreamObserver<RewindI
                 client.rewindInstance("test-instance", null));
 
         assertGrpcCause(ex, Status.Code.NOT_FOUND);
-        // Now goes through the helper, so message contains the operation name
-        assertTrue(ex.getMessage().contains("rewindInstance"));
+        // rewindInstance has its own custom message for NOT_FOUND
+        assertTrue(ex.getMessage().contains("No orchestration instance with ID"));
+        assertTrue(ex.getMessage().contains("was found"));
     }
 
     // -----------------------------------------------------------------------