Add replay test to calculation workflow

Author: longquanzheng

src/test/java/com/uber/cadence/samples/calculation/ReplayTest.java

@@ -0,0 +1,36 @@
+/*
+ *  Copyright 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ *  Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"). You may not
+ *  use this file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file is distributed on
+ *  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ *  express or implied. See the License for the specific language governing
+ *  permissions and limitations under the License.
+ */
+
+package com.uber.cadence.samples.calculation;
+
+import com.uber.cadence.testing.WorkflowReplayer;
+import org.junit.Test;
+
+// This replay test is the recommended way to make sure changing workflow code is backward
+// compatible without non-deterministic errors.
+// "HelloActivity.json" can be downloaded from cadence CLI:
+//      cadence --do samples-domain wf show -w helloworld_d002cd3a-aeee-4a11-aa30-1c62385b4d87
+// --output_filename ~/tmp/HelloActivity.json
+// Or from Cadence Web UI. (You may need to put history file in resources folder; and change
+// workflowType in the first event of history).
+public class ReplayTest {
+  @Test
+  public void testReplay() throws Exception {
+    WorkflowReplayer.replayWorkflowExecutionFromResource(
+        "calculation.workflow.history.json", WorkflowMethodsImpl.class);
+  }
+}