feat: Add support for diff output for failed tests

* currently only works with karma-mocha >= v0.2.2

Closes #26
Closes #32

Gruntfile.js

@@ -26,6 +26,9 @@ module.exports = function (grunt) {
             demo: {
                 configFile: 'demo/karma.conf.js'
             },
+            mocha: {
+                configFile: 'demo/karma.mocha.conf.js'
+            },
             fast: {
                 configFile: 'demo/karma.conf.js',
                 browsers: ['PhantomJS'],
@@ -196,6 +199,7 @@ module.exports = function (grunt) {
     grunt.registerTask('colors', ['copy:demo', 'karma:colors']);
     grunt.registerTask('duplicate', ['copy:demo', 'karma:duplicate']);
     grunt.registerTask('reload', ['copy:demo', 'karma:reload']);
+    grunt.registerTask('mocha', ['copy:demo', 'karma:mocha']);
     grunt.registerTask('demo', [
         'copy:demo',
         'karma:singleBrowser',
@@ -207,6 +211,7 @@ module.exports = function (grunt) {
         'karma:noColors',
         'karma:colors',
         'karma:duplicate',
+        'karma:mocha',
         'karma:reload'
     ]);
 

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2013-2015 Litixsoft GmbH <info@litixsoft.de>
+Copyright (C) 2013-2016 Litixsoft GmbH <info@litixsoft.de>
 Licensed under the MIT license.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy

README.md

@@ -119,6 +119,46 @@ module.exports = function(config) {
 };
 ```
 
+### showDiff
+**Type:** String | Boolean
+
+Shows a diff output. Is disabled by default. All credits to the contributors of [mocha](https://github.com/mochajs/mocha), since the diff logic is used from there and customized for this module.
+
+![screenshot](demo/diff.png)
+
+Currently only works with karma-mocha >= v0.2.2 Not supported for karma-jasmine since the additional properties needed to render the diff are not supported in jasmine yet.
+
+**Possible Values:**
+
+Value | Description
+------ | -----------
+`true` | prints each diff in its own line, same as `'unified'`
+`'unified'` | prints each diff in its own line
+`'inline'` | prints diffs inline
+
+```js
+// karma.conf.js
+module.exports = function(config) {
+  config.set({
+    frameworks: ['mocha', 'chai'],
+
+    // reporters configuration
+    reporters: ['mocha'],
+
+    // reporter options
+    mochaReporter: {
+      showDiff: true
+    },
+
+    plugins: [
+      'karma-chai',
+      'karma-mocha',
+      'karma-mocha-reporter'
+    ]
+  });
+};
+```
+
 ### divider
 **Type:** String
 
@@ -164,7 +204,7 @@ In lieu of a formal styleguide take care to maintain the existing coding style.
 
 You can preview your changes by running:
 
-    $ grunt demo --force
+    $ npm run demo
 
 ## Release History
 ### v1.1.6

demo/karma.mocha.conf.js

@@ -0,0 +1,73 @@
+module.exports = function (config) {
+    config.set({
+        // base path, that will be used to resolve files and exclude
+        basePath: '../',
+
+        frameworks: ['mocha', 'chai'],
+
+        // list of files / patterns to load in the browser
+        files: [
+            'demo/mocha.spec.js'
+        ],
+
+        mochaReporter: {
+            showDiff: true
+        },
+
+        // use dots reporter, as travis terminal does not support escaping sequences
+        // possible values: 'dots', 'progress'
+        // CLI --reporters progress
+        reporters: ['mocha'],
+
+        // web server port
+        // CLI --port 9876
+        port: 9876,
+
+        // enable / disable colors in the output (reporters and logs)
+        // CLI --colors --no-colors
+        colors: true,
+
+        // level of logging
+        // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
+        // CLI --log-level debug
+        logLevel: config.LOG_INFO,
+
+        // enable / disable watching file and executing tests whenever any file changes
+        // CLI --auto-watch --no-auto-watch
+        autoWatch: false,
+
+        // Start these browsers, currently available:
+        // - Chrome
+        // - ChromeCanary
+        // - Firefox
+        // - Opera
+        // - Safari (only Mac)
+        // - PhantomJS
+        // - IE (only Windows)
+        // CLI --browsers Chrome,Firefox,Safari
+        browsers: [process.env.TRAVIS ? 'Firefox' : 'Chrome'],
+
+        // If browser does not capture in given timeout [ms], kill it
+        // CLI --capture-timeout 5000
+        captureTimeout: 20000,
+
+        // Auto run tests on start (when browsers are captured) and exit
+        // CLI --single-run --no-single-run
+        singleRun: true,
+
+        // report which specs are slower than 500ms
+        // CLI --report-slower-than 500
+        reportSlowerThan: 500,
+
+        plugins: [
+            'karma-mocha',
+            'karma-mocha-reporter',
+            'karma-chrome-launcher',
+            'karma-firefox-launcher',
+            'karma-ie-launcher',
+            'karma-safari-launcher',
+            'karma-phantomjs-launcher',
+            'karma-chai'
+        ]
+    });
+};

demo/mocha.spec.js

@@ -0,0 +1,47 @@
+'use strict';
+
+describe('A mocha test suite', function () {
+
+    it('should work', function () {
+        var expected = 'foo';
+        var actual = 'foo';
+        expect(actual).to.equal(expected);
+    });
+
+    it('should show a string diff', function () {
+        var expected = 'foo';
+        var actual = 'foo bar';
+        expect(actual).to.equal(expected);
+    });
+
+    it('should show an array diff', function () {
+        var expected = [
+            'foo',
+            'bar'
+        ];
+        var actual = [
+            'bar',
+            'baz'
+        ];
+        expect(actual).to.deep.equal(expected);
+    });
+
+    it('should show an object diff', function () {
+        var expected = {
+            foo: 42,
+            bar: 1764,
+            baz: {
+                qux: 'bleep',
+                norf: 'bloop'
+            }
+        };
+        var actual = {
+            bar: 1764,
+            baz: {
+                norf: 'bloop'
+            },
+            random: true
+        };
+        expect(actual).to.deep.equal(expected);
+    });
+});