Added code coverage.

.gitignore

 /node_modules/
 /dist/
+/coverage/
+/.idea/

karma.conf.js

@@ -16,7 +16,7 @@ module.exports = function (config) {
       clearContext: false // leave Jasmine Spec Runner output visible in browser
     },
     coverageIstanbulReporter: {
-      dir: require('path').join(__dirname, '../../coverage/error-types'),
+      dir: __dirname + '/coverage/error-types',
       reports: ['html', 'lcovonly', 'text-summary'],
       fixWebpackSourcePaths: true
     },

package.json

@@ -17,7 +17,7 @@
   },
   "scripts": {
     "build": "ng build",
-    "test": "ng test",
+    "test": "ng test --code-coverage --no-watch --no-progress",
     "lint": "ng lint",
     "package": "ng-packagr"
   },