Do not parse partially filled changes for reviewer updates

Skip reviewer updates grouping for changes that:
- don't have messages
- don't have reviewer updates

Issue 5421

Change-Id: I3edcc3f5b1110506be5f23fcdf37a6bf40fc70c9

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser.js

@@ -24,7 +24,10 @@
   };
 
   GrReviewerUpdatesParser.parse = function(change) {
-    if (!change.messages || !change.reviewer_updates) {
+    if (!change ||
+        !change.messages ||
+        !change.reviewer_updates ||
+        !change.reviewer_updates.length) {
       return change;
     }
     var parser = new GrReviewerUpdatesParser(change);

polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-reviewer-updates-parser_test.html

@@ -39,6 +39,62 @@ limitations under the License.
       sandbox.restore();
     });
 
+    test('ignores changes without messages', function() {
+      var change = {};
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_filterRemovedMessages');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_groupUpdates');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_formatUpdates');
+      assert.strictEqual(GrReviewerUpdatesParser.parse(change), change);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._filterRemovedMessages.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._groupUpdates.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._formatUpdates.called);
+    });
+
+    test('ignores changes without reviewer updates', function() {
+      var change = {
+        messages: [],
+      };
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_filterRemovedMessages');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_groupUpdates');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_formatUpdates');
+      assert.strictEqual(GrReviewerUpdatesParser.parse(change), change);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._filterRemovedMessages.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._groupUpdates.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._formatUpdates.called);
+    });
+
+    test('ignores changes with empty reviewer updates', function() {
+      var change = {
+        messages: [],
+        reviewer_updates: [],
+      };
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_filterRemovedMessages');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_groupUpdates');
+      sandbox.stub(
+          GrReviewerUpdatesParser.prototype, '_formatUpdates');
+      assert.strictEqual(GrReviewerUpdatesParser.parse(change), change);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._filterRemovedMessages.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._groupUpdates.called);
+      assert.isFalse(
+          GrReviewerUpdatesParser.prototype._formatUpdates.called);
+    });
+
     test('filter removed messages', function() {
       var change = {
           messages: [