testing angular components with jest gives resolveComponentResources

Issue

I'm trying to test Angular components with jest via jest-preset-angular

it can run the test by karma with ng test, but running the same test by jest gives the error

AppComponent › should create the app

    Component 'AppComponent' is not resolved:
     - templateUrl: ./app.component.html
     - styleUrls: ["./app.component.scss"]
    Did you run and wait for 'resolveComponentResources()'?

reproduction

steps to create this reproduction (see the git commits for steps)

1- generate a new angular project ng new myproject 2- install jest dependencies 3- create jest config file 4- copy and modify src/app/app.component.spec.ts to app.component.spec.jest.ts

running the reproduction

to test app.component.spec.ts file by karma run npm t or ng test and then run npm run test:jest to test app.component.spec.jest.ts by jest

Solution

The problem is detailed here: https://github.com/thymikee/jest-preset-angular/issues/951

For my part it worked when I added the following in jest.config.js:

module.exports = {
  transform: {
    '^.+\\.(ts|js|html)$': 'jest-preset-angular'
  },
};

They also suggest setting up this in jest.preset.js, but that wasn't necessary for me...

const nxPreset = require('@nrwl/jest/preset');

module.exports = {
   ...nxPreset,
   testEnvironment: 'jsdom',
   transform: {
      '^.+\\.(ts|js|html)$': 'jest-preset-angular'
   }
};

Answered By - Bratt