Jest Expect Standalone
Jest Expect Standalone Library. Use the expect package from the facebook/jest project in the browser without any troubles.
What and why
Previously, the expect library was maintained over at
mjackson/expect. However, the author decided
to donate the project over to facebook/jest. See more information about this
process in
facebook/jest/issues/1679.
Before the donation, the expect library was hosted on various CDNs, and you
could easily include it as a script tag in some HTML file. It was usually done
for quick testing/prototyping of code in online tools such as
JSFiddle, JS Bin, or
Plunker. One good example of expect usage for educational
purposes is in the series of lectures
Getting Started with Redux - Egghead
by Dan Abramov.
After the handover of expect library, it became almost impossible to quickly
include it in HTML code as a script tag. One possibility of how it can be achieved
is illustrated in the JS Bin sample
jsbin/nucimeceve. However, the
method is cumbersome, and the result is slow. This is partly because
facebook/jest uses expect as an internal dependency, and does not
bundle it as a standalone UMD module.
This project intends to make available expect library as a standalone library
for easy inclusion inside the browser via a script tag. jest-expect-standalone
will be made available via CDN, and updated each time facebook/jest project
updates their internal expect library.
Usage
Include jest-expect-standalone as a script tag, and you will have the library
available via window.expect.
<script src="https://unpkg.com/jest-expect-standalone@latest/dist/expect.min.js"></script>
See sample JS Bin jsbin/wapokahaxe.
Or copy and paste the following HTML code in your editor, and hack away:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>Running jest-expect-standalone</title>
<script src="https://unpkg.com/jest-expect-standalone@latest/dist/expect.min.js"></script>
<script>
try {
expect(true).toEqual(false);
console.log('Test #1 passed!');
} catch (err) {
console.log(err);
console.log('Test #1 failed!');
}
try {
expect(2).toEqual(2);
console.log('Test #2 passed!');
} catch (err) {
console.log(err);
console.log('Test #2 failed!');
}
</script>
</head>
<body>
</body>
</html>
Building & running tests
To hack away on this project, clone this repository and change to it's root directory.
After installing NPM modules with npm install, you have the following commands available:
npm run build
npm run test
License
This project is licensed under the MIT License. See LICENSE for more details.