Unit Tests

Electrode Component Archetype supports Karma and Jest as its javascript unit tests runners. It allows Karma and Jest unit tests to coexist, and will automatically detect and run both. Component Archetype offers developers with different options for the productive testing environments.


Component Archetype supports Karma as its Javascript test runner with the Mocha testing framework. It has two options for the headless website testing: Chrome and PhantomJS. Headless Chrome is the default option. You can specify the browser by setting the KARMA_BROWSER env to chrome or phantomjs.

Disabling Karma

If you prefer Jest only for writing your unit tests, then you can explicitly turn off Karma support and skip installing the dependencies required. To do that, create a file archetype/config/index.js in your component packages/[component], and add the following code to it:

module.exports = {
options: {
karma: false

You have to do this for every component you have under your lerna packages structure.

Run your karma tests

To run your karma unit tests, simply place your component tests inside packages/[component]/test folder. And run npm run test.


The Component Archetype also takes Jest as its delightful javascript testing option. It has a built-in Jest configuration, and you can also extend it from your app level. Jest parallelizes test runs across workers to maximize performance.

Run your jest tests

To run your jest unit tests, simply place your tests in the packages/[component]/__test__ folder, or name your test files with a .spec.js or .test.js extension along with your packages/[component]/src folder. Whatever you prefer, Jest will find and run your tests.

Extend your jest config

The Component Archetype also takes customized Jest config from your component level. To do that, create a file packages/[component]/archetype/config/index.js, and put the contents below:

module.exports = {
jest: {
// sepcify your jest config here