Use istanbul to measure karma code coverage

Notes:

- browserify-istanbul is used instead of a karma-coverage preprocessor
  because of this bug:
  karma-runner/karma-coverage#16 (comment)
- karma-coverage version pinned to 0.2.6 to workaround this bug:
  karma-runner/karma-coverage#123 (comment)

.gitignore

@@ -1,4 +1,5 @@
 .idea
+coverage
 node_modules
 server/datasources.local.json
 server/model-config.local.json

karma.conf.js

@@ -1,6 +1,8 @@
 // Karma configuration
 // Generated on Sun Jan 18 2015 21:07:20 GMT-0800 (PST)
 
+var istanbul = require('browserify-istanbul');
+
 module.exports = function(config) {
   config.set({
 
@@ -32,15 +34,25 @@ module.exports = function(config) {
 
     browserify: {
       debug: true,
-      transform: ['brfs'],
+      transform: ['brfs', istanbul({
+        ignore: ['**/node_modules/**', '**/spec/**'],
+      })],
       bundleDelay: 1000
     },
 
 
     // test results reporter to use
     // possible values: 'dots', 'progress'
     // available reporters: https://npmjs.org/browse/keyword/karma-reporter
-    reporters: ['dots'],
+    reporters: ['coverage', 'dots'],
+
+
+    coverageReporter: {
+      reporters: [
+        {type: 'html'},
+        {type: 'cobertura'},
+      ],
+    },
 
 
     // web server port

package.json

@@ -39,6 +39,7 @@
     "loopback-explorer": "^1.1.0"
   },
   "devDependencies": {
+    "browserify-istanbul": "^0.1.5",
     "frisby": "git+https://github.com/vlucas/frisby.git",
     "gulp": "^3.8.10",
     "gulp-develop-server": "^0.2.5",
@@ -52,6 +53,7 @@
     "karma": "^0.12.31",
     "karma-browserify": "^2.0.0",
     "karma-chrome-launcher": "^0.1.7",
+    "karma-coverage": "^0.2.6",
     "karma-jasmine": "^0.3.5",
     "strongloop": "^2.10.2"
   }