How do I add code coverage to Typescript + Webpack + Karma w/ Istanbul-Instrumenter

Question

I have created a simple Webpack + Typescript + Karma app but I am having trouble getting the code coverage to work properly. Per projects like this and the other info provided here you can see I tried...

// In test bundle
const componentsContext = require.context('../src/', true, /\.js$/);
componentsContext.keys().forEach(componentsContext);

// In webpack config
const helpers = require('./helpers.js')
const webpackMerge = require('webpack-merge'); // used to merge webpack configs
const commonConfig = require('./webpack.common.js'); // the settings that are common to prod and dev
const HtmlWebpackPlugin = require('html-webpack-plugin');
module.exports = function () {
  return webpackMerge(commonConfig(), {
    devtool: 'inline-source-map',
    output: {
        path: helpers.root("dist"),
        filename: '[name].bundle.js',
    },
    module: {
      postLoaders: [
        {
          test: /^((?!\.spec\.ts).)*.ts$/,
          exclude: /(node_modules|bower_components)/,
          loader: 'istanbul-instrumenter'
        }
      ]
    }
  })
};

but when I run karma start test/karma.conf.js I see 100% and no files listed. What am I missing?

Answer 1

Seems fixed on this branch https://github.com/jrgleason/webpack-karma-coverage-demo/tree/fixed . Not exactly sure what fixed it though.