revertable-globals

Sets globals in a JavaScript environment that can be easily reverted to restore the original environment; useful for testing code that relies on the presence of certain globals.

Setup

To install with npm, run:

npm install revertable-globals --save-dev

API

Table of contents

• function revertableGlobals

function revertableGlobals

Sets globals that can be easily reverted to restore the original environment.

Returns: Function — Reverts the globals.

Examples

How to import.

import revertableGlobals from 'revertable-globals';

How to set and revert fetch related globals for a test.

import fetch, { Request, Response } from 'node-fetch';
import revertableGlobals from 'revertable-globals';

const revertGlobals = revertableGlobals({
  fetch,
  Request,
  Response,
});

try {
  // Test assertions here…
} finally {
  revertGlobals();
}

How to set and revert an environment variable at runtime for a test.

import revertableGlobals from 'revertable-globals';

const revertEnv = revertableGlobals({ FORCE_COLOR: '1' }, process.env);

try {
  // Test assertions here…
} finally {
  revertEnv();
}