Package Exports

@web/test-runner-mocha
@web/test-runner-mocha/dist/autorun.js

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Readme

Test Runner Mocha

Test framework implementation of Mocha for Web Test Runner

See @web/test-runner for a default implementation and CLI for the test runner.

Writing tests

Writing JS tests

Mocha relies on global variables, in any JS test file describe and it are available globally and can be used directly:

describe('my test', () => {
  it('foo is bar', () => {
    if ('foo' !== 'bar') {
      throw new Error('foo does not equal bar');
    }
  });
});

Writing HTML tests

If you're writing tests as HTML, you can import this library to run tests with mocha:

<html>
  <body>
    <script type="module">
      // after importing "@web/test-runner-mocha", describe and it will be available globally
      import { runTests } from '@web/test-runner-mocha';

      describe('my test', () => {
        it('foo is bar', () => {
          if ('foo' !== 'bar') {
            throw new Error('foo does not equal bar');
          }
        });
      });

      // you need to call runTests() when you've loaded all your tests
      runTests();
    </script>
  </body>
</html>

Configuring mocha options

You can configure mocha options using the testFramework.config option:

module.exports = {
  testFramework: {
    config: {
      ui: 'bdd',
      timeout: '2000',
    },
  },
};

The config entry accepts any of the official mocha browser options.

Libraries

@open-wc/testing is a general purpose library, including assertions via chai, HTML test fixtures, a11y tests and test helpers.

It is an opinionated implementation which brings together multiple libraries. You could also use the individual libraries together:

For stubbing and mocking, we recommend sinon which ships an es module variant out of the box:

import { stub, useFakeTimers } from 'sinon';