feat: support Jest 29

[Tommy228]

Summary

This PR is my attempt at addressing #1774 and supporting Jest 29.

This migrates all ts-jest configs under globals, which is deprecated, to transformers config.

It also exposes a new defaultTransformerOptions object to allow overriding the default transformer more easily.

const { defaultTransformerOptions } = require('jest-preset-angular/presets');

Test plan

I linked it to one of my biggest projects running Angular 15 with 3000+ unit tests. The tests have passed with no warning.

Does this PR introduce a breaking change?

• Yes

Overriding the config via globals may not work:

module.exports = {
  globals: {
    'ts-jest': {
      tsconfig: '<rootDir>/src/tsconfig.spec.json',
    },
  },
};

Because the preset now provides the config via the transformer, the default configuration (like tsconfig) takes precedence over the globals configuration.

Instead, this needs to be done (unless there is a better solution?):

const { defaultTransformerOptions } = require('jest-preset-angular/presets');

module.exports = {
  ...defaultConf,
  transform: {
    '^.+\\.(ts|js|mjs|html|svg)$': [
      'jest-preset-angular',
      {
        ...defaultTransformerOptions,
        tsconfig: '<rootDir>/src/tsconfig.spec.json',
      },
    ],
  },
};

Other information

Not sure if I did this right. I'm struggling to get NgJestTransformer unit tests to work. They are working individually but they fail when ran together. I think it has to do with some caching stuff behind TsJestTransformer.

@angular-builders/jest needs to be updated as well because it passes the tsconfig via globals, which does not work anymore.

Todo

• Investigate failing TsJestTransformer tests
• Upgrade ts-jest to include this patch
• Create 13.x documentation (remove changes done to 12.x)
• Update examples

[ahnpnl]

so far it's in good direction. Using Jest transform option like this is the correct way

[Tommy228]

Thanks for having a look!

After some debugging, I think I found what's causing my tests to fail in sequence.

It was indeed a caching issue on ts-jest side. TsJestTransformer uses the globals config as cache key before it is merged with the transform config. So the tests use the cached configuration, even if transform options have changed. I'll create a PR to fix this.

[Tommy228]

Small update about the current status: I won't have time to continue working on this before the end of the week. But what's left to do (cf. the tasks):

• Upgrade ts-jest to include this patch (but this requires a release of ts-jest)
• Create a 13.x documentation (remove changes done to 12.x)
• Update the examples under /examples to use transform
• And of course, test that this didn't break anything

Help is welcome

[viceice]

Your patch was released as v29.0.4🎉

• https://github.com/kulshekhar/ts-jest/blob/HEAD/CHANGELOG.md#%E2%80%8B2904-httpsgithubcomkulshekharts-jestcomparev2903v2904-2023-01-10

[kbrilla]

@Tommy228 hey any updates on this? Is it ready for the second round of review maybe?

[ahnpnl]

done in #1937