Generate complete jest config for angular libraries

Expected Behavior

When generating a new angular library, a complete jest.config.js file should be generated, including everything needed for jest-preset-angular.

This would allow using the jest CLI directly which has a few benefits:

• easier integration of vscode-jest
• ability to run a single unit test file without specifying the library first
• ability to run all unit tests in one go

Current Behavior

The jest.config.js does not include all necessary config properties required to run the tests. Instead, those are patched by the nx jest builder, preventing configuration by the user.

Steps to Reproduce

1. Create nx workspace
2. Generate a new angular library
3. Try to run unit tests using the Jest CLI (cd <path_to_library_root> && jest)
4. See failing tests

Solution

I would solve this by renaming skipSerializers to something like useAngularPreset, controlling all required properties for jest-preset-angular.

I’m happy to do a PR for this if that’s the way to go.

Related

#2768 #2377 #2314 #1506 #1091

[FERNman]

For us it’s been resolved with the new jest.preset.js - thanks @Nx-team! 😄

[FERNman]

@wrslatz @jeserkin I just wanted to add the solution we are using to run tests using VSCode-Jest. This issue is somewhat of a requirement for it though (at least without touching generated libs), as all libs must have a working jest config.

I’ve uploaded the script on gist: https://gist.github.com/FERNman/14e3fe4086d6040cbb1f8e6174c9f0c6

What it does is pretty much a simplified version of nx affected:test combined with the Jest CLI. For some jest parameters (mainly arrays), the method parseJestArgs must probably be adapted.

Also, it may require maintenance from time to time if the nx workspace interface changes, but that should not happen too often.