hops-msw

Please see the main Hops Readme for general information and a Getting Started Guide.

This is a preset for Hops that can be used to set up a Mock Service Worker for your Hops app. It allows to mock REST and GraphQL APIs in unit and integration tests.

This package (together with jest-preset-hops) takes care of setting up the MSW mock server already, so if you use it for unit-testing, you do not need to do this yourself.

Installation

Add this preset to your existing Hops React project:

npm install --save hops-msw

In order to use it for unit-testing, you also need to install the jest-preset-hops package.

Note: Please be aware that only one service worker can exist per scope. Therefore hops-msw does not work together with hops-pwa.

Usage

Set the environment variable ENABLE_MSW to true when running your unit tests.

Example:

import { render, waitFor } from '@testing-library/react';
import { getMockServer } from 'hops-msw/unit';
import { graphql } from 'hops-msw';
import { withApolloTestProvider } from 'hops-react-apollo';

it('loads graphql data', async () => {
  getMockServer().use(
    graphql.query('search', (req, res, ctx) => {
      return res(
        ctx.data({
          __typename: 'Query',
          user: {
            __typename: 'User',
            name: 'Something',
          },
        })
      );
    })
  );

  const { getByText } = render(withApolloTestProvider(<HomeWithData />));

  await waitFor(() => getByText('Something'));
});

Read the MSW documentation for more information on how to write mocks.

See here an example of how to write an integration test using puppeteer.

Configuration

Preset Options

Name	Type	Default	Required	Description
mockServiceWorkerHandlersFile	String	''	no	The path to your mock handlers file (which will be used during development)
mockServiceWorkerUri	String	<basePath>/sw.js	no	The path on which the mock service worker will be served from

mockServiceWorkerHandlersFile

Use this option to register an array of handlers. These will be used during development if ENABLE_MSW=true is set. See here for an example.

Note: Unfortunately the handlers must be written in ES5 (no import/export) until we can drop Node.js 12 support.

"hops": {
  "mockServiceWorkerHandlersFile": "<rootDir>/mocks.js"
}

mockServiceWorkerUri

Usually this doesn't need to be changed.