js-tdd-kit (JavaScript TDD Kit)

Getting started

1. Clone the repository into your "new-project" directory

   git clone git@github.com:lfurzewaddock/js-tdd-kit.git new-project && cd new-project

2. Remove the git repository, and then initialise a new one

   rm -rf .git && git init

3. Remove README and replace with your own

   rm README.md && touch README.md

4. Update package.json and install dependencies

   npm init && npm install

   Don't forget to update the description, contact details, URL's, etc. in the package.json file.

5. Test configuration

Run the various commands on the sample files included. Assuming everything works as expected feel free to delete the contents of both src and test directories, excluding files test/utils.js and test/jsdom.environment.js which are used to include jsdom. See sample files for an example implementation.

Commands

$ npm run ...	Description:
testBuildBrowser	Webpack builds test files in to the dist directory, suitable for a web browser. Open /dist/index.html in a web browser to see test results in the dev tools console.
testBuildNode	Webpack builds test files in to the dist directory, suitable for Node. In the termimal run node_modules/.bin/tape dist/jsdom.environment.js dist/app.bundle.js to see test results.
testNodeBundle	runs testBuildNode, before running tests, piping results to tap-spec CLI terminal reporter.
test	runs ES6+ Tape tests using esm (ES module loader), avoiding Babel, piping results to tap-spec CLI terminal reporter.
testCoverage	runs ES6+ Tape tests using @babel/register, using Babel, enabling NYC to instrument code, piping results to tap-spec CLI terminal reporter.
testStart	Webpack Dev Server compiles test files, opening output in default web browser. See test results in the web browser dev tools console.
testem	TDD UX: runs ES6+ Tape tests using esm (ES module loader), avoiding Babel, with fail/pass tally in the terminal and watches for changes.
debug	runs ES6+ Tape tests with inspector protocol configured to enable process debugging using esm (ES module loader), avoiding Babel.
devBuild	Webpack builds src files in to the dist directory, configured for development, suitable to open in a web browser.
devWatch	runs devBuild and watches for changes.
devStart	Webpack Dev Server compiles src files, opening output in default web browser.
prodBuild	Webpack builds src files in to the dist directory, configured for production, suitable to open in a web browser.
lint	ESLint lint files and reports issues (read only).
lintFix	ESLint lint files and attempts to fix issues automatically (write).
coverage	sets Node env to dev, NYC instruments code by running ES6+ Tape tests using Babel.
coverReport	runs coverage command before NYC generates HTML report from instrumented code, opening report in default web browser.

Further reading / Notes

MS VS Code

I develop on MS Windows 10 Pro using WSL (Windows Subsystem for Linux) and my preferred editor is MS VS Code which includes an integrated terminal for tests to run on a bash CLI provided by WSL, the ability to carry out line by line debugging and extensions to add support for ESLint, Prettier and various other tools/utilities or other functionality.

Therefore, .vscode/launch.json is included in the project to support my environment, but is optional, so can be can be edited to suit your environment or excluded from your project, by removing the relevant comment in .gitignore.

MS VS Code users, should either install current release of MS VS Code extension: WSL workspaceFolder or replace command reference in .vscode/launch.json

Webpack

This project uses Webpack v4 for bundling files with npm commands suitable for both web browser and/or Node environments.

Babel

Webpack is set to use Babel v7 configured in .babelrc to transpile ES6+ to ES5. The source files under the src directory use ESM (ECMAScript Module) syntax and are transpiled using plugins add-module-exports and transform-es2015-modules-umd to ES5 UMD (Universal Module Definition), so they can be run in Node or a web browser.

ESLint

The Webpack plugin eslint-loader runs ESLint configured in .eslintrc.json and .eslintignore automatically on files under the src directory for development and production builds, but not test code and if any issues are found, will abort, reporting these issues.

esm (ES module loader)

Tests are run directly on the ES6+ source files under the src directory avoiding Webpack and Babel transpilation to ES5 by using esm (ES module loader), greatly improving performance.

Prettier

Prettier configured in .prettierrc.json and .prettierignore is integrated into ESLint and run from the command line (See lint commands above). eslint-config-prettier (turns off all ESLint rules that conflict with Prettier) and eslint-plugin-prettier (integrates Prettier rules into ESLint rules).

Tape/TDD

• TDD the RITE Way
• Why I use Tape Instead of Mocha & So Should You
• 5 Questions Every Unit Test Must Answer
• The Outrageous Cost of Skipping TDD & Code Reviews
• Github Tape repo
• Github tape-promise repo
• Testing Express APIs with Tape and Supertest
• Unit Testing with Tape
• Move Fast and Don’t Break Things
• Learn Tape

JSDOM

jsdom is included for testing code that requires a Web Browser on the command line, such as DOM manipulation, to facilitate a fast, integrated TDD experience.

To avoid the antipattern of copying globals from a jsdom window onto the Node.js global object; https://github.com/jsdom/jsdom/wiki/Don't-stuff-jsdom-globals-onto-the-Node-global, in the file test/jsdom.environment.js, jsdom is made available on the Node.js global object under the namespace: jsTddKitLfurzewaddockComGithub which can be invoked in a fixture setup function within tests that need it.

Currently, it is not possible to bundle jsdom with Webpack jsdom/jsdom#2066, which is why test/jsdom.environment.js is written using standard ES5 CommonJS syntax, so it does not need to be included in the bundle by Webpack.

Other approaches not encouraged by jsdom which add jsdom to the node process global object include:

• https://zinserjan.github.io/mocha-webpack/docs/guides/jsdom.html

Other potential ways using npm packages;

• browser-env
• window
• jsdom-global
• shim-webpack-require-for-node-tests