Running Jest (namely jest-circus) outside of Node

🚀 Feature Proposal

I am looking at running jest-circus outside of Node and it mostly works but there are some transitive dependencies on Node built-ins like fs that don’t make a lot of sense in non-Node environments. This is a proposal to make jest-circus run outside of Node and add a test to keep it running.

Motivation

The motivation is to run Jest tests fully outside of Node to test running in an authentic environment as opposed to the use case for more pure JS.

Example

E.g. use Webpack to create a bundle with jest-circus.

Pitch

This change needs to be made to jest-circus itself. One concrete suggestion is to split jest-util into two packages, jest-util and jest-pure-utils/jest-universal-utils (no dependencies on non-pure modules) and for jest-circus to use jest-pure-utils.

[ide]

I ended up using Jasmine for now so I probably won’t work on this soon.

[ide]

I was trying to run jest-circus on a phone (web & Expo) to run tests on a real device like expect(someDeviceApi()).toBe(...). jest-circus used to run outside of Node when it was first in beta but as @aaronabramov mentioned some more dependencies were added.