[Bug]: Class constructor FormControl cannot be invoked without 'new'

[GeorgeKnap]

Version

27.2.3

Steps to reproduce

here is the public repo with the issue

The issue is in the workspace jest-error-repo it uses NX workspace with Jest. Run the test of the library inside with nx test test-this-lib

in the native angular repo which uses Karma test passes.
I also put the issue in ng-stack/forms

Expected behavior

no error

Actual behavior

jest throws following error:

TypeError: Class constructor FormControl cannot be invoked without 'new'

       8 | })
       9 | export class TestThisComponentComponent {
    > 10 |   control = new FormControl<string>('init value');
         |             ^
      11 | }
      12 |

Additional context

No response

Environment

System:
    OS: Windows 10 10.0.22000
    CPU: (16) x64 Intel(R) Core(TM) i9-10885H CPU @ 2.40GHz
  Binaries:
    Node: 16.10.0 - C:\Program Files\nodejs\node.EXE
    npm: 8.3.0 - C:\Program Files\nodejs\npm.CMD

[GeorgeKnap]

after importing NgStackFormsModule in the test module the error changes to
https://user-images.githubusercontent.com/11920691/151941714-18c6dca3-076b-42aa-902d-f009cfab1e72.png

[SimenB]

Neither of these errors are thrown by Jest, your issue probably lies with a transformer or custom wrapping code

[GeorgeKnap]

@SimenB In there repo there are just files scaffolded during generating project, nothing custom, nothing special.

[SimenB]

That might be, that still doesn't mean it's a bug in Jest. I've not used Angular since v1, so I have zero frame of reference to know what's going on, and I'm not gonna spend the time to try to understand how projects using it are structured. It's 99.999% certain the issue is due to a transformer though (Jest only runs JS, and since there is TS in your snippet, that means there's a transformer between the source code and the TypeError, which is a runtime error).

Just like projects created using create-react-app aren't minimal reproductions, ones created with Nx aren't. If you can strip away all the abstractions added on top of Jest I can take a look (so you're left with pretty much just the transformer and some setup code, maybe some other bits and bobs), but I assume that by the time you've done that you'll discover the source of the error yourself 🙂 https://github.com/GeorgeKnap/jest-ng-stack-forms-error/blob/f5daeddcca25b9d383f5d4fd25848c2f6f9a9f24/jest-error-repo/package.json#L13-L56 is not minimal even though a tool generated most of it

[GeorgeKnap]

@SimenB I have created pure Angular 13 + Jest repo (taken mostly from jest-preset-angular example)
https://github.com/GeorgeKnap/angular-jest-ng-stack-forms
is it better repo to investigate?
the error that jest is throwing now is Unexpected value 'NgStackFormsModule' imported by the module 'DynamicTestModule'. Please add an @NgModule annotation.

[SimenB]

Better, definitely! That error is still an Angular specific one, though, not from Jest. I'd rip out the preset and as much typescript as you can.

Seeing as I don't think this is a bug in Jest, I'll close this issue. We recommend using StackOverflow or our discord channel for questions.

If after you've gotten an answer from those forums, you still think it's a bug in Jest, I'm happy to take a look. But I'm almost entirely certain your issue is a configuration errors. If with Jest, probably a transformer. I have no frame of reference to say if the @angular/testing stuff is used correctly. But in the end, all the errors you're getting is runtime errors when executing your code, which Jest has little to do with directly

[GeorgeKnap]

After including ngcc in postinstall script as suggested here angular#35805 I'm back with the
Class constructor FormControl cannot be invoked without 'new'

[github-actions]

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