README.md

Sample test lib with coverage report from "in-browser" test run

1. Use webpack with istanbul-instrumenter-loader resolver to instrument test bundle.

    module: {
        rules: [
            // instrument only testing sources with Istanbul
            {
                test: /\.js$/,
                use: { loader: 'istanbul-instrumenter-loader' },
                include: path.resolve('lib/')
            }
        ]
    },

See ./webpack.config.js

As for now, mocha-webdriver-runner doesn't have direct support for capturing nyc instrumentation result, but we know that its stored in global __coverage__ and has to be saved in .nyc_output*.json to be picked up by nyc report, so

2. Use -S option of mocha-driver-runner to capture globals after tests:

$ webpack -d
$ mocha-webdriver-runner --headless-chrome -S __coverage__:.nyc_output/test.json ./dist/test/index.html

See ./package.json

3. Generate report

$ npx nyc report --reporter=text
npx: installed 144 in 5.916s
----------|----------|----------|----------|----------|-------------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
----------|----------|----------|----------|----------|-------------------|
All files |    83.33 |       75 |      100 |    83.33 |                   |
 lib.js   |    83.33 |       75 |      100 |    83.33 |                 3 |
----------|----------|----------|----------|----------|-------------------|
ERROR: Coverage for lines (83.33%) does not meet global threshold (90%)

Profit!