jest-performance-testing

jest-performance-testing

You can get benefit by using this lib with react-performance-testing. This lib is created to improve DX for react-performance-test users. You can write test quickly and easy.

Table of Contents

• Installation
• API
  • toBeMounted
  • toBeMountedWithin
  • toBeUpdatedWithin
  • toBeRenderedTimes
• LICENSE

Installation

npm:

npm install --save-dev jest-performance-testing

yarn:

yarn add --dev jest-performance-testing

Note: If you are using TypeScript, we are recommending to import this lib in local file like *.test.ts | *.spec.ts. This is because, we have expanded jest types, so global types are not recognized by some editors if you import this lib in setup file. If you want to import this lib in setup file, please see here testing-library/jest-dom#123 (comment).

API

toBeMounted

toBeMounted()

This matcher is to check if component is mounted.

expect(renderCount.current.Component).toBeMounted();

You can use renderTime as bellow.

expect(renderTime.current.Component).toBeMounted();

toBeMountedWithin

toBeMountedWithin(mountedTime: number)

This matcher is to check if mounted time is less than expected time.

expect(renderTime.current.Component).toBeMountedWithin(16); // ms

toBeUpdatedWithin

toBeUpdatedWithin(updatedTime: number[])

This matcher is to check if some updated time are less than expected time.

expect(renderTime.current.Component).toBeUpdatedWithin([
  10, // first render
  15, // second render
  20, // third render
]);

If you have same render time, you can write as bellow.

// All items are 16ms
expect(renderTime.current.Component).toBeUpdatedWithin(16);

toBeRenderedTimes

toBeRenderedTimes(renderedTimes: number)

This matcher is to check if number of renders are equality.

expect(renderCount.current.Component).toBeRenderedTimes(1);

LICENSE

MIT