https://github.com/launchdarkly/jest-launchdarkly-mock

Easily unit test LaunchDarkly feature flagged components with jest
https://github.com/launchdarkly/jest-launchdarkly-mock

feature feature-flags feature-toggles flags jest launchdarkly mock test unit

Last synced: 13 days ago
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Easily unit test LaunchDarkly feature flagged components with jest

• Host: GitHub
• URL: https://github.com/launchdarkly/jest-launchdarkly-mock
• Owner: launchdarkly
• License: apache-2.0
• Created: 2020-09-22T20:41:49.000Z (about 4 years ago)
• Default Branch: main
• Last Pushed: 2024-10-23T18:30:56.000Z (20 days ago)
• Last Synced: 2024-10-25T02:44:10.529Z (19 days ago)
• Topics: feature, feature-flags, feature-toggles, flags, jest, launchdarkly, mock, test, unit
• Language: TypeScript
• Homepage:
• Size: 224 MB
• Stars: 25
• Watchers: 29
• Forks: 19
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE
  • Codeowners: CODEOWNERS

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README

        
# jest-launchdarkly-mock

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> **Easily unit test LaunchDarkly feature flagged components with jest** :clap:

This package is only compatible with the react sdk.

## Installation

```bash

yarn add -D jest-launchdarkly-mock

```

or

```bash

npm install jest-launchdarkly-mock --save-dev

```

Then in `jest.config.js` add jest-launchdarkly-mock to setupFiles: 

```js

// jest.config.js

module.exports = {

  setupFiles: ['jest-launchdarkly-mock'],

}

```

## Usage

Use the only 3 apis for test cases:

* `mockFlags(flags: LDFlagSet)`: mock flags at the start of each test case. Only mocks

flags returned by the `useFlags` hook.

* `ldClientMock`: a jest mock of the [ldClient](https://launchdarkly.github.io/js-client-sdk/interfaces/_launchdarkly_js_client_sdk_.ldclient.html). All

methods of this object are jest mocks.

* `resetLDMocks` : resets both mockFlags and ldClientMock.

## Example

```tsx

import { mockFlags, ldClientMock, resetLDMocks } from 'jest-launchdarkly-mock'

describe('button', () => {

  beforeEach(() => {

    // reset before each test case

    resetLDMocks()

  })

  test('flag on', () => {

      // arrange

      // You can use the original unchanged case, kebab-case, camelCase or snake_case keys.

      mockFlags({ devTestFlag: true })

  

      // act

      const { getByTestId } = render()

      // assert

      expect(getByTestId('test-button')).toBeTruthy()

    })

  test('identify', () => {

    // arrange

    mockFlags({ 'dev-test-flag': true })

    

    // act

    const { getByTestId } = render()

    fireEvent.click(getByTestId('test-button'))

    // assert: identify gets called

    expect(ldClientMock.identify).toBeCalledWith({ key: 'aa0ceb' })

  })

})

```