https://github.com/sebinsua/test-react-shallow-equal

🐢💨💨💨 Unit test against performance problems.
https://github.com/sebinsua/test-react-shallow-equal

jasmine jest matchers performance react redux render shallow-compare shallow-equal test unit-testing

Last synced: about 2 months ago
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🐢💨💨💨 Unit test against performance problems.

• Host: GitHub
• URL: https://github.com/sebinsua/test-react-shallow-equal
• Owner: sebinsua
• Created: 2017-09-12T07:54:10.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2017-09-25T09:21:29.000Z (over 7 years ago)
• Last Synced: 2024-10-18T08:35:38.976Z (3 months ago)
• Topics: jasmine, jest, matchers, performance, react, redux, render, shallow-compare, shallow-equal, test, unit-testing
• Language: JavaScript
• Homepage:
• Size: 131 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# `test-react-shallow-equal`

> Unit test against inadvertent performance problems.

Provides a `toShallowEqual` matcher for `jest` and `jasmine`. This matcher can aid in writing performant code as it allows you to write unit tests which [ensure that `shallowEqual` always returns `true` when the underlying values tested have not changed](https://medium.com/@esamatti/react-js-pure-render-performance-anti-pattern-fb88c101332f).

## Usage

The tests give examples of how to use this to test [`mapStateToProps`](./packages/jest-react-shallow-equal/src/__tests__/mapStateToProps.js), [higher-order components (HOCs)](./packages/jest-react-shallow-equal/src/__tests__/HOC.js) and normal [component renders](./packages/test-react-shallow-equal/src/__tests__/ensureInternalPropsAreShallowEqual.js).

## Install

### Installing `jest` matchers

```sh

npm install --save-dev jest-react-shallow-equal

```

```js

import installShallowEqualMatcher from 'jest-react-shallow-equal'

installShallowEqualMatcher()

test('should x when y', () => {

  // ...

})

```

### Installing `jasmine` matchers

```sh

npm install --save-dev jasmine-react-shallow-equal

```

The `installShallowEqualMatcher` function must be called within a spec's `beforeEach` or `beforeAll` and must be run before testing code.

```js

import installShallowEqualMatcher from 'jasmine-react-shallow-equal'

describe('some suite', () => {

  beforeAll(() => installShallowEqualMatcher())

  it('some test', () => {

    // ...

  })

})

```