CoverageWorkspace

🔎 Nx is a set of Extensible Dev Tools for Monorepos.

Further info on NX itself

Visit the Nx Documentation to learn more.

Running the example

Preparation

Install the packages as usual with npm install

If you haven't used nx before, you might need to run npm install @nrwl/nx as well.

Running

At least on Windows, there might be problems with locating nyc. You can solve that by either putting your node_modules/.bin on PATH (and of course restarting your terminal to make sure it's applied) or prefixing all execution commands with npx.

NX-style

NX generates a lot of commands to run the application, also with more elaborate configurations. They can be run directly in command line, being specified in nx.json.

For running e2e-Tests of the app, run

nx run cov-app-e2e:e2e

For running the Component-Tests against a Storybook-Instance, run

nx run ui-lib-e2e:e2e

Both calls take care of starting their targets themselves.

Plan B

For users preferring scripts in package.json, you could also use scripts app-e2e for the classic e2e-Test against an application or lib-e2e for Component-Tests against Storybook

In webpack.config mind the include - all correct paths to sources that shall be instrumented/you want coverage for in this e2e-Project, have to be declared correctly. If you want coverage for specs as well, remove corresponding entries from exclude.

Changes needed in your NX-Setup

This repo essentially followed the instructions of https://github.com/skylock/cypress-angular-coverage-example, but will expand on the details that took me a while to figure out, necessary to have a successful setup.

Skylock's Setup, with hints

• Install ngx-build-plus to extends the Angular CLI's build process and instrument the code. It enables adding an additional webpack-config which takes care of the instrumentation of the application when it is served.

npm i -D ngx-build-plus

• Add webpack coverage config file coverage.webpack.js to cypress folder (in this example, it's the app cov-app-e2e). In include, make sure all desired source-folders are listed, with correct paths relative to the webpack config.

module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|ts)$/,
        loader: 'istanbul-instrumenter-loader',
        options: { esModules: true },
        enforce: 'post',
        include: [
          require('path').join(__dirname, '..', 'cov-app/src'),
          require('path').join(__dirname, '../..', 'libs/ui-lib/src')
        ],
        exclude: [
          /\.(e2e|spec)\.ts$/,
          /node_modules/,
          /(ngfactory|ngstyle)\.js/
        ]
      }
    ]
  }
};

• Update angular.json to use ngx-build with extra config, it extends the previous configuration with the instrumentation step. In NX Setup, serve is called on test startup, so with this configuration both ng serve and nx run cov-app result in instrumented code.

"serve": {
          "builder": "ngx-build-plus:dev-server",
          "options": {
            "browserTarget": "cypress-angular-coverage-example:build",
            "extraWebpackConfig": "./cypress/coverage.webpack.js"
          },

• Instrument JS files with istanbul-lib-instrument for subsequent code coverage reporting

npm i -D istanbul-instrumenter-loader

• Make Istanbul understand your Typescript source files

npm i -D @istanbuljs/nyc-config-typescript source-map-support ts-node

• Make sure that Istanbul takes advantage of it by adding this configuration in your package.json or in .nycrc.json, on the same level as e.g. scripts

  "nyc": {
    "extends": "@istanbuljs/nyc-config-typescript",
    "all": true
  },

• Add cypress code coverage plugin

  npm install -D @cypress/code-coverage nyc istanbul-lib-coverage

• Then add the code below to your supportFile and pluginsFile

// cypress/support/index.js
import '@cypress/code-coverage/support'

// cypress/plugins/index.js
module.exports = (on, config) => {
  on('task', require('@cypress/code-coverage/task'))
}

Summarized setup for a regular app, i.e. cov-app + cov-app-e2e

• Install dependencies

  npm i -D ngx-build-plus
  npm i -D istanbul-instrumenter-loader
  npm i -D @istanbuljs/nyc-config-typescript source-map-support ts-node
  npm install -D @cypress/code-coverage nyc istanbul-lib-coverage

• Provide additional webpack-config coverage.webpack.js in cov-app-e2e, make sure paths are all listed and correct

module.exports = {
  module: {
    rules: [
      {
        test: /\.(js|ts)$/,
        loader: 'istanbul-instrumenter-loader',
        options: { esModules: true },
        enforce: 'post',
        include: [
          require('path').join(__dirname, '..', 'cov-app/src'),
          require('path').join(__dirname, '../..', 'libs/ui-lib/src')
        ],
        exclude: [
          /\.(e2e|spec)\.ts$/,
          /node_modules/,
          /(ngfactory|ngstyle)\.js/
        ]
      }
    ]
  }
};

• Change angular.json for cov-app

"serve": {
          "builder": "ngx-build-plus:dev-server",
          "options": {
            "browserTarget": "cypress-angular-coverage-example:build",
            "extraWebpackConfig": "./cypress/coverage.webpack.js"
          },

• Add global config to package.json (same level as e.g. scripts)

  "nyc": {
    "extends": "@istanbuljs/nyc-config-typescript",
    "all": true
  },

• Configure cypress-plugin in cov-app-e2e

// cypress/support/index.js
import '@cypress/code-coverage/support'

// cypress/plugins/index.js
module.exports = (on, config) => {
  on('task', require('@cypress/code-coverage/task'))
}

Coverage Report with Highlighting can be found after test execution in /coverage/lcov-report/index.html

Configuration for e2e-Tests against Storybook

• Install dependencies, build-plus is (probably) not necessary as there's already a webpack-configuration we can modify towards our needs.

  npm i -D istanbul-instrumenter-loader
  npm i -D @istanbuljs/nyc-config-typescript source-map-support ts-node
  npm install -D @cypress/code-coverage nyc istanbul-lib-coverage

• Add instrumentation configuration into webpack.config.js in .storybook directory inside the tested library (here: ui-lib). As Storybook already makes use of Webpack, this step replaces the additional webpack-config and the alteration of the configuration in angular.json.

const rootWebpackConfig = require('../../../.storybook/webpack.config');
// Export a function. Accept the base config as the only param.
module.exports = async ({ config, mode }) => {
  config = await rootWebpackConfig({ config, mode });
  config.module.rules.push({
    test: /\.(js|ts)$/,
    loader: 'istanbul-instrumenter-loader',
    options: { esModules: true },
    enforce: 'post',
    include: require('path').join(__dirname, '..', 'src')
  });
  // Return the altered config
  return config;
};

• Add global config to package.json (same level as e.g. scripts)

  "nyc": {
    "extends": "@istanbuljs/nyc-config-typescript",
    "all": true
  },

• Configure cypress-plugin in ui-lib-e2e

// cypress/support/index.js
import '@cypress/code-coverage/support'

// cypress/plugins/index.js
module.exports = (on, config) => {
  on('task', require('@cypress/code-coverage/task'))
}

Coverage Report with Highlighting can be found after test execution in /coverage/lcov-report/index.html.