javascript code coverage using Selenium + istanbul

https://github.com/alex028502/istanbulseleniumexample

I had trouble understanding that too, so I made the above example with webpack.

module.exports = {  devtool: 'source-map',  mode: 'none',  module: {    rules: [      // { test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },      {        resolve: {          extensions: ['.js'],        },        use: {          loader: 'istanbul-instrumenter-loader',          options: {esModules: true},        },        enforce: 'post',        exclude: /node_modules/,      },      {        test: /\.coffee$/,        use: [          {loader: 'coffee-loader'},        ],      },    ],  },  entry: './src/index.js',  output: {    path: __dirname + '/public/',    filename: 'index.js',  },};

and then if you are running instrumented code in the browser, you can download it like this

coverage_info = _driver.execute_script('return JSON.stringify(window.__coverage__);')# each report needs a unique name# but we don't care for this example which report corresponds# to which testtimestamp = datetime.datetime.timestamp(datetime.datetime.now())file = open("nyc_output/coverage%s.json" % timestamp, 'w')file.write(coverage_info)file.close()

and then generate a report like this

node_modules/.bin/nyc report -t nyc_output

If you are not using webpack, you just instrument your code using the command line as in the example you pasted in, and it creates a new folder with the instrumented code.

# from https://medium.com/@the1mills/front-end-javascript-test-coverage-with-istanbul-selenium-4b2be44e3e98mkdir public-coveragecp -a public/. public-coverage/   # copy all files overistanbul instrument public \     --output public-coverage \    --embed-source true

The part that I was able to do without from the link you mentioned is the istanbul middleware