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Mocha

Environment variables

Sometimes you might want your test to make use of variables set on an environment level. Common reasons for this include:

  • Flagging a run as CI
  • Setting the domain of an application
  • Pointing to a test database
  • Setting a key which you want to remain secure

The best way to do this is to use NodeJS’s native environment variables.

Example

In your package.json or directly in a terminal set your variable name and value.

Terminal window
env CI=STAGE mocha

Then in your test or code reference it via process.env.CI. e.g.

if (process.env.CI === "STAGE") // do something

The value is available from anywhere in a spec file allowing you to set values from it before the tests run. e.g.

import { equal } from "assert";
import { loadPage } from "your-code";
const URL = `${process.env.APP_HOST}/${process.env.APP_URI}`;
describe('Test the page loads', () {
  it('goes to URL', () => {
    const page = loadPage(URL);
    equal(page.url, URL);
  });
});