Error while running Jest tests in @nrwl/nx workspace

Issue

I recently started to convert my Angular apps and libs into an @nrwl/nx workspace. The apps are running fine, however when it comes to my Jest tests I get some strange errors.

The workspace is a standard NX workspace created with

npx create-nx-workspace

No changes to the generated jest config files.

When starting my tests for one of my libs with

nx test my-lib-name

simple tests run fine. However when a test imports some external modules like e.g. @ngx-translate/core/TranslateModule or different ngx-bootstrap modules I get the following error:

Unexpected value 'TranslateModule' imported by the module 'DynamicTestModule'. Please add an @NgModule annotation.

My test looks like this:

import { ComponentFixture, waitForAsync, TestBed } from '@angular/core/testing';
import { TranslateModule } from '@ngx-translate/core';
import { BsModalRef, ModalModule } from 'ngx-bootstrap/modal';

import { ErrorDialogComponent } from './error-dialog.component';

describe('ErrorDialogComponent', () => {
  let comp: ErrorDialogComponent;
  let fixture: ComponentFixture<ErrorDialogComponent>;

  beforeEach(waitForAsync(() => {
    TestBed.configureTestingModule({
      declarations: [
        ErrorDialogComponent,
      ],
      imports: [
        TranslateModule.forRoot(),
        ModalModule.forRoot()
      ],
      providers: [
        BsModalRef
      ]
    }).compileComponents()
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(ErrorDialogComponent);
    comp = fixture.componentInstance;

    fixture.detectChanges();
  });

  it('should create component', () => {
    expect.assertions(1);

    expect(comp).toBeTruthy();
  });
});

And my jest.config.js inside the lib like this:

module.exports = {
  displayName: 'my-lib-name',
  preset: '../../jest.preset.js',
  setupFilesAfterEnv: ['<rootDir>/src/test-setup.ts'],
  globals: {
    'ts-jest': {
      tsconfig: '<rootDir>/tsconfig.spec.json',
      stringifyContentPathRegex: '\\.(html|svg)$',
    },
  },
  coverageDirectory: '../../coverage/libs/my-lib-name',
  transform: {
    '^.+\\.(ts|mjs|js|html)$': 'jest-preset-angular',
  },
  snapshotSerializers: [
    'jest-preset-angular/build/serializers/no-ng-attributes',
    'jest-preset-angular/build/serializers/ng-snapshot',
    'jest-preset-angular/build/serializers/html-comment',
  ]
};

Global jest.presets.js and jest.config.js (both unchanged since generation):

// jest.presets.js

const nxPreset = require('@nrwl/jest/preset');
module.exports = { ...nxPreset };



// jest.config.js

const { getJestProjects } = require('@nrwl/jest');
module.exports = {
  projects: getJestProjects(),
};

I already searched a lot but couldn't find any answer. I hope any one could help. If you need more information please let me know.

Solution

It turned out that a dependency (I don't know which one) was broken or buggy. A clean reinstallation of all dependencies fixed the error message.

Answered By - Gerry