From 49eb9b44e9382628459edbbabd84cc8daf395450 Mon Sep 17 00:00:00 2001
From: Capacitor Set <CapacitorSet@users.noreply.github.com>
Date: Thu, 13 Oct 2016 09:00:16 +0200
Subject: [PATCH] Add --no-diff option (fixes mochajs/mocha#2514)

---
 bin/_mocha                                   |  7 +++++++
 lib/mocha.js                                 | 15 +++++++++++++++
 lib/reporters/base.js                        |  3 ++-
 test/integration/fixtures/no-diff.fixture.js |  8 ++++++++
 test/integration/no-diff.spec.js             | 14 ++++++++++++++
 test/reporters/base.spec.js                  | 15 +++++++++++++++
 6 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 test/integration/fixtures/no-diff.fixture.js
 create mode 100644 test/integration/no-diff.spec.js

diff --git a/bin/_mocha b/bin/_mocha
index 6cfc094ba1..b3f8d2f505 100755
--- a/bin/_mocha
+++ b/bin/_mocha
@@ -90,6 +90,7 @@ program
   .option('--preserve-symlinks', 'Instructs the module loader to preserve symbolic links when resolving and caching modules')
   .option('--icu-data-dir', 'include ICU data')
   .option('--inline-diffs', 'display actual/expected differences inline within each string')
+  .option('--no-diff', 'do not show a diff on failure')
   .option('--interfaces', 'display available interfaces')
   .option('--no-deprecation', 'silence deprecation warnings')
   .option('--no-exit', 'require a clean shutdown of the event loop: mocha will not call process.exit')
@@ -242,6 +243,12 @@ if (program.inlineDiffs) {
   mocha.useInlineDiffs(true);
 }
 
+// --no-diff
+
+if (process.argv.indexOf('--no-diff') !== -1) {
+  mocha.hideDiff(true);
+}
+
 // --slow <ms>
 
 if (program.slow) {
diff --git a/lib/mocha.js b/lib/mocha.js
index dcc1492f5a..378c5ddbd3 100644
--- a/lib/mocha.js
+++ b/lib/mocha.js
@@ -380,6 +380,20 @@ Mocha.prototype.useInlineDiffs = function (inlineDiffs) {
   return this;
 };
 
+/**
+ * Do not show diffs at all.
+ *
+ * @param {Boolean} hideDiff
+ * @return {Mocha}
+ * @api public
+ * @param {boolean} hideDiff
+ * @return {Mocha}
+ */
+Mocha.prototype.hideDiff = function (hideDiff) {
+  this.options.hideDiff = hideDiff !== undefined && hideDiff;
+  return this;
+};
+
 /**
  * Set the timeout in milliseconds.
  *
@@ -509,6 +523,7 @@ Mocha.prototype.run = function (fn) {
     exports.reporters.Base.useColors = options.useColors;
   }
   exports.reporters.Base.inlineDiffs = options.useInlineDiffs;
+  exports.reporters.Base.hideDiff = options.hideDiff;
 
   function done (failures) {
     if (reporter.done) {
diff --git a/lib/reporters/base.js b/lib/reporters/base.js
index 205488426a..961c07e449 100644
--- a/lib/reporters/base.js
+++ b/lib/reporters/base.js
@@ -200,8 +200,9 @@ exports.list = function (failures) {
     if (err.uncaught) {
       msg = 'Uncaught ' + msg;
     }
+
     // explicitly show diff
-    if (err.showDiff !== false && sameType(actual, expected) && expected !== undefined) {
+    if (exports.hideDiff !== true && err.showDiff !== false && sameType(actual, expected) && expected !== undefined) {
       escape = false;
       if (!(utils.isString(actual) && utils.isString(expected))) {
         err.actual = actual = utils.stringify(actual);
diff --git a/test/integration/fixtures/no-diff.fixture.js b/test/integration/fixtures/no-diff.fixture.js
new file mode 100644
index 0000000000..22b80ae86e
--- /dev/null
+++ b/test/integration/fixtures/no-diff.fixture.js
@@ -0,0 +1,8 @@
+'use strict';
+var assert = require('assert');
+
+describe('Example test', function () {
+  it('should fail', function () {
+    assert.deepEqual([1, 2, 3], ['foo', 'bar', 'baz']);
+  });
+});
diff --git a/test/integration/no-diff.spec.js b/test/integration/no-diff.spec.js
new file mode 100644
index 0000000000..5766abce51
--- /dev/null
+++ b/test/integration/no-diff.spec.js
@@ -0,0 +1,14 @@
+'use strict';
+
+var helpers = require('./helpers');
+var run = helpers.runMocha;
+
+describe('no-diff', function () {
+  it('should be honoured', function (done) {
+    run('no-diff.fixture.js', ['--no-diff'], function (err, res) {
+      res.output.should.not.match(/\+ expected/);
+      res.output.should.not.match(/- actual/);
+      done(err);
+    });
+  });
+});
diff --git a/test/reporters/base.spec.js b/test/reporters/base.spec.js
index 6282d882ff..9bcbaf561a 100644
--- a/test/reporters/base.spec.js
+++ b/test/reporters/base.spec.js
@@ -88,6 +88,21 @@ describe('Base reporter', function () {
       errOut.should.not.match(/\- actual/);
       errOut.should.not.match(/\+ expected/);
     });
+
+    it('should not show diffs when hideDiff is set', function () {
+      var err = new Assert({ actual: 'foo', expected: 'bar' });
+      var errOut;
+
+      var test = makeTest(err);
+
+      Base.hideDiff = true;
+      Base.list([test]);
+      Base.hideDiff = false; // Revert to original value
+
+      errOut = stdout.join('\n');
+      errOut.should.not.match(/\- actual/);
+      errOut.should.not.match(/\+ expected/);
+    });
   });
 
   describe('Getting two strings', function () {