NODE_ENV with Jest

Question

I am migrating from Mocha to Jest. My test imports the config package, which selects a configuration file or another depending on the NODE_ENV environment variable. However, it looks like NODE_ENV is found while running the test from Jest

Next line does not work (that is, NODE_ENV is ignored):

 NODE_ENV=test jest test/*.js --notify --config jest.config.json

As a consequence the config package reports:

console.error node_modules/config/lib/config.js:1727
WARNING: NODE_ENV value of 'test' did not match any deployment config file names. 

Do you know how to include NODE_ENV?

Answer 1

Jest automatically defines environment variable NODE_ENV as test(see https://jestjs.io/docs/environment-variables), as you can confirm from your error message:

console.error node_modules/config/lib/config.js:1727
WARNING: NODE_ENV value of 'test' did not match any deployment config file names. 

What you can do is simply create config/test.json and include the contents {}, which is an empty valid JSON object.

See https://github.com/lorenwest/node-config/wiki/Strict-Mode

Note: the aforementioned error occurs when you use the config package, and meanwhile you don't have the test.json file in the config directory.