1 files changed, 19 insertions, 0 deletions
diff --git a/config/karma.config.js b/config/karma.config.js
index 44229e2ee88..2f3cc932413 100644
--- a/config/karma.config.js
+++ b/config/karma.config.js
@@ -2,8 +2,20 @@ var path = require('path');
 var webpackConfig = require('./webpack.config.js');
 var ROOT_PATH = path.resolve(__dirname, '..');
 
+// add coverage instrumentation to babel config
+if (webpackConfig && webpackConfig.module && webpackConfig.module.rules) {
+  var babelConfig = webpackConfig.module.rules.find(function (rule) {
+    return rule.loader === 'babel-loader';
+  });
+
+  babelConfig.options = babelConfig.options || {};
+  babelConfig.options.plugins = babelConfig.options.plugins || [];
+  babelConfig.options.plugins.push('istanbul');
+}
+
 // Karma configuration
 module.exports = function(config) {
+  var progressReporter = process.env.CI ? 'mocha' : 'progress';
   config.set({
     basePath: ROOT_PATH,
     browsers: ['PhantomJS'],
@@ -15,6 +27,13 @@ module.exports = function(config) {
     preprocessors: {
       'spec/javascripts/**/*.js?(.es6)': ['webpack', 'sourcemap'],
     },
+    reporters: [progressReporter, 'coverage-istanbul'],
+    coverageIstanbulReporter: {
+      reports: ['html', 'text-summary'],
+      dir: 'coverage-javascript/',
+      subdir: '.',
+      fixWebpackSourcePaths: true
+    },
     webpack: webpackConfig,
     webpackMiddleware: { stats: 'errors-only' },
   });