XUnit reporter should handle exceptions during diff generation (#4068)

Author: rgroothuijsen

lib/reporters/base.js

@@ -154,14 +154,14 @@ exports.cursor = {
  }
 };
 
-function showDiff(err) {
+var showDiff = (exports.showDiff = function(err) {
  return (
  err &&
  err.showDiff !== false &&
  sameType(err.actual, err.expected) &&
  err.expected !== undefined
  );
-}
+});
 
 function stringifyDiffObjs(err) {
  if (!utils.isString(err.actual) || !utils.isString(err.expected)) {
@@ -182,9 +182,19 @@ function stringifyDiffObjs(err) {
  * @return {string} Diff
  */
 var generateDiff = (exports.generateDiff = function(actual, expected) {
- return exports.inlineDiffs
- ? inlineDiff(actual, expected)
- : unifiedDiff(actual, expected);
+ try {
+ return exports.inlineDiffs
+ ? inlineDiff(actual, expected)
+ : unifiedDiff(actual, expected);
+ } catch (err) {
+ var msg =
+ '\n ' +
+ color('diff added', '+ expected') +
+ ' ' +
+ color('diff removed', '- actual: failed to generate Mocha diff') +
+ '\n';
+ return msg;
+ }
 });
 
 /**

lib/reporters/xunit.js

@@ -163,9 +163,9 @@ XUnit.prototype.test = function(test) {
  if (test.state === STATE_FAILED) {
  var err = test.err;
  var diff =
- Base.hideDiff || !err.actual || !err.expected
- ? ''
- : '\n' + Base.generateDiff(err.actual, err.expected);
+ !Base.hideDiff && Base.showDiff(err)
+ ? '\n' + Base.generateDiff(err.actual, err.expected)
+ : '';
  this.write(
  tag(
  'testcase',

test/reporters/xunit.spec.js

@@ -350,6 +350,42 @@ describe('XUnit reporter', function() {
  '</failure></testcase>';
  expect(expectedWrite, 'to be', expectedTag);
  });
+
+ it('should handle non-string diff values', function() {
+ var runner = new EventEmitter();
+ createStatsCollector(runner);
+ var xunit = new XUnit(runner);
+
+ var expectedTest = {
+ state: STATE_FAILED,
+ title: expectedTitle,
+ parent: {
+ fullTitle: function() {
+ return expectedClassName;
+ }
+ },
+ duration: 1000,
+ err: {
+ actual: 1,
+ expected: 2,
+ message: expectedMessage,
+ stack: expectedStack
+ }
+ };
+
+ sandbox.stub(xunit, 'write').callsFake(function(str) {
+ expectedWrite += str;
+ });
+
+ runner.emit(EVENT_TEST_FAIL, expectedTest, expectedTest.err);
+ runner.emit(EVENT_RUN_END);
+ sandbox.restore();
+
+ var expectedDiff =
+ '\n + expected - actual\n\n -1\n +2\n ';
+
+ expect(expectedWrite, 'to contain', expectedDiff);
+ });
  });
 
  describe('on test pending', function() {