[TEST] Fix random test failure in GetWatchResponseTests

Author: jimczi

client/rest-high-level/src/main/java/org/elasticsearch/client/watcher/WatchStatus.java

@@ -26,6 +26,7 @@
 import org.joda.time.DateTime;
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
@@ -125,7 +126,7 @@ public static WatchStatus parse(XContentParser parser) throws IOException {
         DateTime lastChecked = null;
         DateTime lastMetCondition = null;
         Map<String, ActionStatus> actions = null;
-        Map<String, String> headers = null;
+        Map<String, String> headers = Collections.emptyMap();
         long version = -1;
 
         ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.currentToken(), parser::getTokenLocation);

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/watcher/watch/WatchStatus.java

@@ -234,6 +234,8 @@ public void readFrom(StreamInput in) throws IOException {
         }
         if (in.readBoolean()) {
             headers = in.readMap(StreamInput::readString, StreamInput::readString);
+        } else {
+            headers = Collections.emptyMap();
         }
     }
 

x-pack/plugin/core/src/test/java/org/elasticsearch/protocol/xpack/watcher/GetWatchResponseTests.java

@@ -140,12 +140,10 @@ private static WatchStatus randomWatchStatus() {
             );
             actionMap.put(randomAlphaOfLength(10), actionStatus);
         }
-        Map<String, String> headers = randomBoolean() ? new HashMap<>() : null;
-        if (headers != null) {
-            int headerSize = randomIntBetween(1, 5);
-            for (int i = 0; i < headerSize; i++) {
-                headers.put(randomAlphaOfLengthBetween(5, 10), randomAlphaOfLengthBetween(1, 10));
-            }
+        Map<String, String> headers = new HashMap<>();
+        int headerSize = randomIntBetween(0, 5);
+        for (int i = 0; i < headerSize; i++) {
+            headers.put(randomAlphaOfLengthBetween(5, 10), randomAlphaOfLengthBetween(1, 10));
         }
         return new WatchStatus(version, state, executionState, lastChecked, lastMetCondition, actionMap, headers);
     }