HOW TO: use environment variables

Sometimes you might want your test to make use of variables on an environment-level e.g. flagging a run as CI, setting the domain of your app or pointing to a test db.

To do this you can use NodeJS's native environmental variables.

Example

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

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.

const URL = `${process.env.APP_HOST}/${process.env.APP_URI}`;
describe('Test the page loads',() { 
// tests ...