Adding more tests to WorkflowExecutionUtils (#970)

Should cover all the following path almost 100%:
```
prettyPrintDecisions
  prettyPrintDecision
    prettyPrintObject
      prettyPrintJson
        fixStackTrace
```

Nit change: moved methods around in the source-code to group better.

src/main/java/com/uber/cadence/internal/common/WorkflowExecutionUtils.java

@@ -57,13 +57,8 @@
 import java.nio.ByteBuffer;
 import java.nio.file.Files;
 import java.time.Duration;
-import java.util.Collection;
-import java.util.Date;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.Map.Entry;
-import java.util.Optional;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
@@ -506,24 +501,6 @@ public static String prettyPrintHistory(
     return result.toString();
   }
 
-  public static String prettyPrintDecisions(Iterable<Decision> decisions) {
-    StringBuilder result = new StringBuilder();
-    result.append("{");
-    boolean first = true;
-    for (Decision decision : decisions) {
-      if (first) {
-        first = false;
-      } else {
-        result.append(",");
-      }
-      result.append("\n");
-      result.append(INDENTATION);
-      result.append(prettyPrintDecision(decision));
-    }
-    result.append("\n}");
-    return result.toString();
-  }
-
   /**
    * Returns single event in a human readable format
    *
@@ -561,6 +538,29 @@ private static Object getEventAttributes(HistoryEvent event) {
     }
   }
 
+  /**
+   * Returns decisions in a human readable format
+   *
+   * @param decisions decisions to pretty print
+   */
+  public static String prettyPrintDecisions(Iterable<Decision> decisions) {
+    StringBuilder result = new StringBuilder();
+    result.append("{");
+    boolean first = true;
+    for (Decision decision : decisions) {
+      if (first) {
+        first = false;
+      } else {
+        result.append(",");
+      }
+      result.append("\n");
+      result.append(INDENTATION);
+      result.append(prettyPrintDecision(decision));
+    }
+    result.append("\n}");
+    return result.toString();
+  }
+
   /**
    * Returns single decision in a human readable format
    *
@@ -638,7 +638,8 @@ private static String prettyPrintObject(
       result.append("{ ");
 
       String prefix = "";
-      for (Object entry : ((Map) object).entrySet()) {
+      Map<?, ?> sortedMap = new TreeMap<>((Map<?, ?>) object); // Automatically sorts by keys
+      for (Map.Entry<?, ?> entry : sortedMap.entrySet()) {
         result.append(prefix);
         prefix = ", ";
         result.append(
@@ -652,14 +653,21 @@ private static String prettyPrintObject(
     if (Collection.class.isAssignableFrom(clz)) {
       return String.valueOf(object);
     }
+
     if (!skipLevel) {
       if (printTypeName) {
         result.append(object.getClass().getSimpleName());
         result.append(" ");
       }
       result.append("{");
     }
+
+    // walk through getter methods without params and dump them as
+    // key (method-name) = value (getter-result)
+
     Method[] eventMethods = object.getClass().getDeclaredMethods();
+    Arrays.sort(eventMethods, Comparator.comparing(Method::getName));
+
     boolean first = true;
     for (Method method : eventMethods) {
       String name = method.getName();

src/test/java/com/uber/cadence/internal/common/WorkflowExecutionUtilsTest.java

@@ -17,20 +17,13 @@
 import static org.junit.Assert.*;
 import static org.mockito.Mockito.*;
 
-import com.uber.cadence.EventType;
-import com.uber.cadence.GetWorkflowExecutionHistoryResponse;
-import com.uber.cadence.History;
-import com.uber.cadence.HistoryEvent;
-import com.uber.cadence.StartChildWorkflowExecutionFailedEventAttributes;
-import com.uber.cadence.WorkflowExecution;
-import com.uber.cadence.WorkflowExecutionCloseStatus;
+import com.google.common.collect.ImmutableMap;
+import com.uber.cadence.*;
 import com.uber.cadence.client.WorkflowTerminatedException;
 import com.uber.cadence.client.WorkflowTimedOutException;
+import com.uber.cadence.internal.compatibility.ThriftObjects;
 import com.uber.cadence.serviceclient.IWorkflowService;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.Optional;
+import java.util.*;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -42,6 +35,33 @@ public class WorkflowExecutionUtilsTest {
 
   private IWorkflowService mockService;
   private WorkflowExecution workflowExecution;
+  private final String DECISIONS_PRETTY_PRINT =
+      "{\n"
+          + "  ScheduleActivityTaskDecisionAttributes {\n"
+          + "    ActivityId = activityId;\n"
+          + "    ActivityType = activityName;\n"
+          + "    Domain = domain;\n"
+          + "    Header = {\n"
+          + "      Fields = { key1=value1, key2=value2 };\n"
+          + "      FieldsSize = 2\n"
+          + "    };\n"
+          + "    HeartbeatTimeoutSeconds = 4;\n"
+          + "    Input = input;\n"
+          + "    ScheduleToCloseTimeoutSeconds = 1;\n"
+          + "    ScheduleToStartTimeoutSeconds = 2;\n"
+          + "    StartToCloseTimeoutSeconds = 3;\n"
+          + "    TaskList = taskList\n"
+          + "  },\n"
+          + "  FailWorkflowExecutionDecisionAttributes {\n"
+          + "    Details = {\n"
+          + "      \"error\": \"panic\",\n"
+          + "      \"stackTrace\": \"fn()\n"
+          + "        main()\"\n"
+          + "    };\n"
+          + "    Reason = failure reason\n"
+          + "  },\n"
+          + "  null\n"
+          + "}";
 
   @Before
   public void setUp() {
@@ -400,4 +420,53 @@ public void testGetHistoryPage_ExceptionWhileRetrievingExecutionHistory() throws
 
     assertTrue(exception.getMessage().contains(errMessage));
   }
+
+  @Test
+  public void testPrettyPrintDecisions() throws Exception {
+    final TaskList taskList =
+        new com.uber.cadence.TaskList()
+            .setName("taskList")
+            .setKind(com.uber.cadence.TaskListKind.NORMAL);
+
+    final ActivityType activityType = new ActivityType().setName("activityName");
+    final Header activityHeader =
+        new Header()
+            .setFields(
+                ImmutableMap.of(
+                    "key1", ThriftObjects.utf8("value1"),
+                    "key2", ThriftObjects.utf8("value2")));
+
+    final Decision decisionScheduleActivity =
+        new Decision()
+            .setDecisionType(DecisionType.ScheduleActivityTask)
+            .setScheduleActivityTaskDecisionAttributes(
+                new ScheduleActivityTaskDecisionAttributes()
+                    .setActivityId("activityId")
+                    .setActivityType(activityType)
+                    .setTaskList(taskList)
+                    .setInput(ThriftObjects.utf8("input"))
+                    .setScheduleToCloseTimeoutSeconds(1)
+                    .setScheduleToStartTimeoutSeconds(2)
+                    .setStartToCloseTimeoutSeconds(3)
+                    .setHeartbeatTimeoutSeconds(4)
+                    .setHeader(activityHeader)
+                    .setRequestLocalDispatch(true)
+                    .setDomain("domain"));
+
+    final Decision decisionFailWorkflow =
+        new Decision()
+            .setDecisionType(DecisionType.FailWorkflowExecution)
+            .setFailWorkflowExecutionDecisionAttributes(
+                new FailWorkflowExecutionDecisionAttributes()
+                    .setReason("failure reason")
+                    .setDetails(
+                        ThriftObjects.utf8(
+                            "{\"error\":\"panic\", \"stackTrace\":\"fn()\\nmain()\"}")));
+
+    ArrayList<Decision> decisions =
+        new ArrayList<>(Arrays.asList(decisionScheduleActivity, decisionFailWorkflow, null));
+
+    String result = WorkflowExecutionUtils.prettyPrintDecisions(decisions);
+    assertEquals(DECISIONS_PRETTY_PRINT, result);
+  }
 }