JTBDOS uses Vitest for unit testing. It’s a fast and lightweight testing framework that’s compatible with Jest’s API. Unit tests are run automatically as part of the build task in Turborepo.

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Running Tests

To run tests, simply execute:
Terminal
pnpm test
This will run all tests in the __tests__ folder in each app, however we’ve only written a couple of tests for app project so far.

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Adding Tests

We use Testing Library for our tests. It’s a great library that allows you to test your components in a way that’s close to how a user would interact with them. In the __tests__ folder, create a new file called [page].test.tsx (where [page] is the name of the page you want to test). Here’s an example of a test for the home page:
apps/app/__tests__/home.test.tsx
import { render, screen } from '@testing-library/react';
import { expect, test } from 'vitest';
import Page from '../app/(unauthenticated)/home/page';

test('Home Page', () => {
  render(<Page />);
  expect(
    screen.getByRole('heading', {
      level: 1,
      name: 'Hello, world!',
    })
  ).toBeDefined();
});

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Adding Vitest to other apps

To add Vitest to another app, you’ll need to install the dependencies:
Terminal
pnpm install -D vitest @testing-library/react @testing-library/dom --filter [app]
as well as adding the @repo/testing package to the devDependencies section of the package.json file:
apps/[app]/package.json
"devDependencies": {
  "@repo/testing": "workspace:*"
}
Create a new file called vitest.config.ts in the root of the app and add the following:
apps/[app]/vitest.config.ts
export { default } from '@repo/testing';
Then, create a new file in the __tests__ folder in the relevant app and add a test command to the package.json file:
apps/[app]/package.json
{
  "scripts": {
    "test": "vitest"
  }
}
Turborepo will automatically pick up on the new test script and run the tests. Then, just follow the instructions above to write tests.