Bug: RangeError: Maximum call stack size exceeded when encountering circular reference in component imported using forwardRef

[alexciesielski]

Description of the bug

I am trying to write a test for a recursive standalone component, which imports a parent component, which imports this component, using forwardRef(() => ParentComponent) in the imports: [] array of the Component decorator declaration, like below

@Component({
  selector: 'y42-parent',
  standalone: true,
  imports: [
    CommonModule,
    ChildComponent,
  ],
})
export class ParentComponent {}

@Component({
  selector: 'y42-child',
  standalone: true,
  imports: [
    CommonModule,
    forwardRef(() => ParentComponent),
  ],
})
export class ChildComponent {}

beforeEach(() => MockBuilder(ChildComponent));

RangeError: Maximum call stack size exceeded

at queueTypesFromModulesArrayRecur (../../node_modules/@angular/core/fesm2015/testing.mjs:23577:49)
at ../../node_modules/@angular/core/fesm2015/testing.mjs:23608:29
    at Array.forEach (<anonymous>)
at queueTypesFromModulesArrayRecur (../../node_modules/@angular/core/fesm2015/testing.mjs:23602:34)
at ../../node_modules/@angular/core/fesm2015/testing.mjs:23608:29
    at Array.forEach (<anonymous>)
at queueTypesFromModulesArrayRecur (../../node_modules/@angular/core/fesm2015/testing.mjs:23602:34)
at ../../node_modules/@angular/core/fesm2015/testing.mjs:23608:29
    at Array.forEach (<anonymous>)
at queueTypesFromModulesArrayRecur (../../node_modules/@angular/core/fesm2015/testing.mjs:23602:34)
at ../../node_modules/@angular/core/fesm2015/testing.mjs:23608:29
    at Array.forEach (<anonymous>)

If I comment out the import of the forwardRef the test correctly instantiates the component so it's definitely because of that.
I tried every possible way using .mock, .replace, .keep - but everything results in the above error.

I'm on ng-mocks 14.7.1 and angular 15.2.0

[alexciesielski]

I just updated to latest ng-mocks 14.11.0 and I still get the error

[satanTime]

Hi @alexciesielski,

thank you for reporting the issue.
It looks like an angular issue.

I tested on ng-mocks@14.11.0 and angular@15.2.10 and it works correctly.

Could you confirm it still fails on your side?
The test I'm using is:

import {CommonModule} from '@angular/common';
import {Component, forwardRef,} from '@angular/core';
import {MockBuilder, MockRender, ngMocks} from 'ng-mocks';

@Component({
  selector: 'y42-child',
  standalone: true,
  imports: [
    CommonModule,
    forwardRef(() => ParentComponent),
  ],
  template: 'ChildComponent'
})
export class ChildComponent {}

@Component({
  selector: 'y42-parent',
  standalone: true,
  imports: [
    CommonModule,
    ChildComponent,
  ],
  template: 'ParentComponent',
})
export class ParentComponent {}

describe('my sandbox', () => {
  describe('ChildComponent', () => {
    beforeEach(() => MockBuilder(ChildComponent));

    it('should render ChildComponent', () => {
      const fixture = MockRender(ChildComponent);

      // Asserting it got the right paramId.
      expect(ngMocks.formatText(fixture)).toEqual('ChildComponent');
    });
  });

  describe('ParentComponent',() => {
    beforeEach(() => MockBuilder(ParentComponent));

    it('should render ParentComponent', () => {
      const fixture = MockRender(ParentComponent);

      // Asserting it got the right paramId.
      expect(ngMocks.formatText(fixture)).toEqual('ParentComponent');
    });
  });
});

the result:

> ng test --ts-config ./tsconfig.json --progress=false

15 11 2023 14:37:43.200:INFO [karma-server]: Karma v6.4.2 server started at http://localhost:9877/
15 11 2023 14:37:43.202:INFO [launcher]: Launching browsers ChromeCi with concurrency unlimited
15 11 2023 14:37:43.205:INFO [launcher]: Starting browser ChromeHeadless
15 11 2023 14:37:47.090:INFO [Chrome Headless 101.0.4950.0 (Mac OS 10.15.7)]: Connected on socket 9TlMSNuu1kSnwDp7AAAB with id 90245406
TOTAL: 4 SUCCESS

> jest --config jest.config.ts

jest-haste-map: Haste module naming collision: a15
  The following files share their name; please adjust your hasteImpl:
    * <rootDir>/package.json
    * <rootDir>/dist/lib/package.json

 PASS  src/app/app.component.spec.ts (5.507 s)
 PASS  src/issue/test.spec.ts

Test Suites: 2 passed, 2 total
Tests:       4 passed, 4 total
Snapshots:   0 total
Time:        7.466 s
Ran all test suites.