Draft:Jest (framework)
Jest[1] is a JavaScript testing framework built on top of Jasmine[2] and maintained by Meta (formerly Facebook). It was designed and built by Christoph Nakazawa with a focus on simplicity and support for large web applications. It works with projects using Babel, TypeScript, Node.js, React, Angular, Vue.js and Svelte. Jest doesn't require a lot of configuration for first-time users of a testing framework.
Usage and examples
Installation
Use the JavaScript package manager npm to install Jest in Node.js:<syntaxhighlight lang="bash"> $ npm install --save-dev jest </syntaxhighlight>
Example
In this example, we will write a test case for the following module saved as sum.js:
<syntaxhighlight lang="javascript">
function sum(a, b) {
return a + b;
}
module.exports = sum; </syntaxhighlight>
Our test case will be in a file named sum.test.js for Jest to automatically pick it up as a test case for sum.js.
The contents of the file with the test case will be:
<syntaxhighlight lang="javascript"> const sum = require('./sum');
test('adds 1 + 2 to equal 3', () => {
expect(sum(1, 2)).toBe(3);
}); </syntaxhighlight>
Then, from the command line, we run this command:
<syntaxhighlight lang="bash"> $ npm run test </syntaxhighlight>
This runs the test and outputs the corresponding result on the command line.
See also
References
- ^ "Jest Website".
- ^ "jest/README.md at 88a94d5d1bc1f387317a3068bf510ab992c5dc64 · facebook/jest". GitHub. Retrieved 2022-05-31.
External links
Category:JavaScript libraries Category:JavaScript programming tools Category:Software using the MIT license Category:JavaScript web frameworks