Jest extenstion to simplify testing performance
npm install jest-test-performance
!GitHub
jest-test-performance is a package designed to simplify testing performance.
Performance is notoriously difficult to test in a meaningful way. It varies by network, machine, and all sorts of circumstances outside our control. And it's affected by our psychology; a page that loads something quickly feels faster even if it is just a skeleton of how the page will look.
That doesn't change the fact that performance is meaningful, and we shouldn't disregard it because it's difficult.
This package distills performance down to a single millisecond score that it expects a function to take to run. It can't take in to account every machine, browser, or network, but it provides a baseline based on an average machine, that we can test against.
I would recommend using this more in integration than unit tests, unless you are confident that you have a distinct unit that is a bottleneck.
Add to your project using npm i -D jest-test-performance
First you need to import the package during the jest setup.
``javascript`
"jest": {
"setupFilesAfterEnv": ["jest-test-performance"]
}
And then you can use the condition during assertions.
`javascript``
it('should run faster than 100ms', async () => {
const dummyFunction = () => {};
await expect(dummyFunction).toBeFasterThan(100);
});