test process.env with Jest

Question

I have an app that depends on environmental variables like:

const APP_PORT = process.env.APP_PORT || 8080;

and I would like to test that fo

Answer 1

In ./package.json:

"jest": {
  "setupFiles": [
    "/jest/setEnvVars.js"
  ]
}

In ./jest/setEnvVars.js:

process.env.SOME_VAR = 'value';