Angular + Jest: Can't resolve all parameters for AppComponent: (?)

Question

I am operating inside a Typescript Monorepo. I want to add an Angular 8 frontend with Jest testing to the Monorepo. But I am encountering some issues.

I am using

Angular CLI: 8.3.5

What I did

I will use this repository as a starting point!

1. Create Angular Application

Then in <root>/services I ran:

ng new frontend

After the Angular application was created I was able to run ng test with the following result:

Everything works fine.

2. Add Jest

I am using https://github.com/briebug/jest-schematic to easily add Jest to my Angular application

yarn global add @briebug/jest-schematic
ng add @briebug/jest-schematic

This results in the following changes

Running jest results in the following error:

$ jest
 FAIL  src/app/app.component.spec.ts
  ● Test suite failed to run

    File not found: <rootDir>/src/tsconfig.spec.json (resolved as: /home/flo/Desktop/stackoverflow-monorepo-angular-jest/services/frontend/src/tsconfig.spec.json)

      at ConfigSet.resolvePath (node_modules/ts-jest/dist/config/config-set.js:712:19)
      at ConfigSet.get (node_modules/ts-jest/dist/config/config-set.js:202:67)
      at ConfigSet.tsJest (node_modules/ts-jest/dist/util/memoize.js:43:24)
      at ConfigSet.get (node_modules/ts-jest/dist/config/config-set.js:297:41)
      at ConfigSet.versions (node_modules/ts-jest/dist/util/memoize.js:43:24)
      at ConfigSet.get (node_modules/ts-jest/dist/config/config-set.js:583:32)
      at ConfigSet.jsonValue (node_modules/ts-jest/dist/util/memoize.js:43:24)
      at ConfigSet.get [as cacheKey] (node_modules/ts-jest/dist/config/config-set.js:598:25)
      at TsJestTransformer.getCacheKey (node_modules/ts-jest/dist/ts-jest-transformer.js:126:36)
      at ScriptTransformer._getCacheKey (node_modules/@jest/transform/build/ScriptTransformer.js:266:23)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        1.267s
Ran all test suites.

3. Fixing Errors

Jest tries to find the tsconfig.spec.json in the wrong folder. Fortunately, I found a fix. I needed to change the jest.config.js

module.exports = {
  preset: 'jest-preset-angular',
  setupFilesAfterEnv: ['<rootDir>/src/setup-jest.ts'],
  globals: {
    'ts-jest': {
      tsConfig: '<rootDir>/tsconfig.spec.json',
      diagnostics: false,
      stringifyContentPathRegex: '\\.html$',
      astTransformers: [require.resolve('jest-preset-angular/InlineHtmlStripStylesTransformer')],
    },
  },
};

Now when I run jest it works:

4. My Issue

I've now added the Angular HttClient to my AppComponent:

// app.component.ts

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
})
export class AppComponent {
  title = 'frontend';
  constructor(private http: HttpClient) {}
}

I've also added the HttpClientModule to app.module.ts and to the imports in the app.component.spec.ts.

// app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpClientModule } from '@angular/common/http';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [AppComponent],
  imports: [BrowserModule, AppRoutingModule, HttpClientModule],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {}

// app.component.spec.ts

import { TestBed, async } from '@angular/core/testing';
import { RouterTestingModule } from '@angular/router/testing';
import { AppComponent } from './app.component';
import { HttpClientModule, HttpClient } from '@angular/common/http';

describe('AppComponent', () => {
  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [RouterTestingModule, HttpClientModule],
      declarations: [AppComponent],
    }).compileComponents();
  }));

  it('should create the app', () => {
    const fixture = TestBed.createComponent(AppComponent);
    const app = fixture.debugElement.componentInstance;
    expect(app).toBeTruthy();
  });

  it(`should have as title 'frontend'`, () => {
    const fixture = TestBed.createComponent(AppComponent);
    const app = fixture.debugElement.componentInstance;
    expect(app.title).toEqual('frontend');
  });

  it('should render title', () => {
    const fixture = TestBed.createComponent(AppComponent);
    fixture.detectChanges();
    const compiled = fixture.debugElement.nativeElement;
    expect(compiled.querySelector('.content span').textContent).toContain('frontend app is running!');
  });
});

However, when running jest, I get the following errors:

$ jest
 FAIL  src/app/app.component.spec.ts
  AppComponent
    ✕ should create the app (449ms)
    ✕ should have as title 'frontend' (10ms)
    ✕ should render title (10ms)

  ● AppComponent › should create the app

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsAsync (../../../packages/compiler/src/jit/compiler.ts:69:33)
      at CompilerImpl.compileModuleAndAllComponentsAsync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:69:27)
      at TestingCompilerImpl.compileModuleAndAllComponentsAsync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:57:27)
      at TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:362:27)
      at Function.TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:160:66)
      at testing_1.async (src/app/app.component.spec.ts:11:8)

  ● AppComponent › should create the app

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsSync (../../../packages/compiler/src/jit/compiler.ts:65:38)
      at CompilerImpl.compileModuleAndAllComponentsSync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:61:35)
      at TestingCompilerImpl.compileModuleAndAllComponentsSync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:52:27)
      at TestBedViewEngine._initIfNeeded (../../../../packages/core/testing/src/test_bed.ts:376:28)
      at TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:570:10)
      at Function.TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:232:36)
      at it (src/app/app.component.spec.ts:15:29)

  ● AppComponent › should have as title 'frontend'

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsAsync (../../../packages/compiler/src/jit/compiler.ts:69:33)
      at CompilerImpl.compileModuleAndAllComponentsAsync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:69:27)
      at TestingCompilerImpl.compileModuleAndAllComponentsAsync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:57:27)
      at TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:362:27)
      at Function.TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:160:66)
      at testing_1.async (src/app/app.component.spec.ts:11:8)

  ● AppComponent › should have as title 'frontend'

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsSync (../../../packages/compiler/src/jit/compiler.ts:65:38)
      at CompilerImpl.compileModuleAndAllComponentsSync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:61:35)
      at TestingCompilerImpl.compileModuleAndAllComponentsSync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:52:27)
      at TestBedViewEngine._initIfNeeded (../../../../packages/core/testing/src/test_bed.ts:376:28)
      at TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:570:10)
      at Function.TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:232:36)
      at it (src/app/app.component.spec.ts:21:29)

  ● AppComponent › should render title

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsAsync (../../../packages/compiler/src/jit/compiler.ts:69:33)
      at CompilerImpl.compileModuleAndAllComponentsAsync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:69:27)
      at TestingCompilerImpl.compileModuleAndAllComponentsAsync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:57:27)
      at TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:362:27)
      at Function.TestBedViewEngine.compileComponents (../../../../packages/core/testing/src/test_bed.ts:160:66)
      at testing_1.async (src/app/app.component.spec.ts:11:8)

  ● AppComponent › should render title

    Can't resolve all parameters for AppComponent: (?).

      at syntaxError (../../../packages/compiler/src/util.ts:100:17)
      at CompileMetadataResolver._getDependenciesMetadata (../../../packages/compiler/src/metadata_resolver.ts:957:27)
      at CompileMetadataResolver._getTypeMetadata (../../../packages/compiler/src/metadata_resolver.ts:836:20)
      at CompileMetadataResolver.getNonNormalizedDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:377:18)
      at CompileMetadataResolver.loadDirectiveMetadata (../../../packages/compiler/src/metadata_resolver.ts:224:11)
      at ../../../packages/compiler/src/jit/compiler.ts:135:36
          at Array.forEach (<anonymous>)
      at ../../../packages/compiler/src/jit/compiler.ts:133:65
          at Array.forEach (<anonymous>)
      at JitCompiler._loadModules (../../../packages/compiler/src/jit/compiler.ts:130:71)
      at JitCompiler._compileModuleAndAllComponents (../../../packages/compiler/src/jit/compiler.ts:115:32)
      at JitCompiler.compileModuleAndAllComponentsSync (../../../packages/compiler/src/jit/compiler.ts:65:38)
      at CompilerImpl.compileModuleAndAllComponentsSync (../../../packages/platform-browser-dynamic/src/compiler_factory.ts:61:35)
      at TestingCompilerImpl.compileModuleAndAllComponentsSync (../../../../packages/platform-browser-dynamic/testing/src/compiler_factory.ts:52:27)
      at TestBedViewEngine._initIfNeeded (../../../../packages/core/testing/src/test_bed.ts:376:28)
      at TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:570:10)
      at Function.TestBedViewEngine.createComponent (../../../../packages/core/testing/src/test_bed.ts:232:36)
      at it (src/app/app.component.spec.ts:27:29)

Test Suites: 1 failed, 1 total
Tests:       3 failed, 3 total
Snapshots:   0 total
Time:        1.682s, estimated 2s
Ran all test suites.
error Command failed with exit code 1.

The tests run just fine when using Jasmine + Karma. It seems like something went wrong with the dependency injection when using jest for testing.

You can find the repository here: https://github.com/flolude/stackoverflow-monorepo-angular-jest/commit/9a2d8cac0dfa25a5f6620f38238c3f577b2acb63 to try it yourself.

Try mocking your dependency instead of importing the exact same one. You also have the testing implementation of that service. — user4676340, Commented Sep 24, 2019 at 7:50
Mocking wouldn't change anything, because I haven't created my own Service (the issue is caused by something else)... The HttpClientTestingModule doesn't work, either... The strange thing is that is works fine when I follow the same steps in a standard Karma-Jasmine testing environment — Florian Ludewig, Commented Sep 24, 2019 at 9:37
You can't say that mocking wouldn't change anything. That's the basics of unit testing. For all I know, you didn't import the HTTP module in your test, hence resulting in that error. By the way, it would be great if you could post your code, because we can't tell you what's wrong with it if we don't see it ... — user4676340, Commented Sep 24, 2019 at 9:43
(And no, I do not want to browse your github to find the code, and you're supposed to post your code on your question in case the external link doesn't work) — user4676340, Commented Sep 24, 2019 at 9:44
@Maryannah you are totally right! My fault. I've added the code snippets now :) — Florian Ludewig, Commented Sep 24, 2019 at 10:03

Dima Mamchur · Accepted Answer · 2019-09-26 10:38:17Z

48

+100

Just set the emitDecoratorMetadata to true in your tsconfig.spec.json.

This allows the ts-jest not to lose the metadata during the TypeScript transpilation. This issue came unexpected for jest-preset-angular developer after the Angular updated to version 8.1

Here's the issue on jest-preset-angular GitHub: https://github.com/thymikee/jest-preset-angular/issues/288

edited Sep 26, 2019 at 10:38

answered Sep 26, 2019 at 10:31

Dima Mamchur

1,1149 silver badges8 bronze badges

perfect. had exactly the same issue today and this solved it.
– Markus Dresch
Commented Sep 26, 2019 at 10:42
1

Interestingly enough, I had this set on the tsconfig.json file, which my tsconfig.spec.json inherited from, but I still had to set this option in the tsconfig.spec.json file. Thanks!
– Matt
Commented Nov 5, 2019 at 14:54
1

Also interesting: I had it only in the tsconfig.spec.json first and it had not effect, so I moved the property into tsconfig.json (from which tsconfig.spec.json inherits) and only then it worked. Kind of the opposite of what Matt experienced. Bottom Line: Before you give up, try all combinations :-)
– Till Kuhn
Commented May 19, 2021 at 13:46

Add a comment |

Collectives™ on Stack Overflow

Angular + Jest: Can't resolve all parameters for AppComponent: (?)

What I did

1. Create Angular Application

2. Add Jest

3. Fixing Errors

4. My Issue

1 Answer 1

Your Answer

Not the answer you're looking for? Browse other questions tagged
angular
typescript
jestjs
angular8
monorepo
or ask your own question.

Linked

Hot Network Questions

Collectives™ on Stack Overflow

What I did

1. Create Angular Application

2. Add Jest

3. Fixing Errors

4. My Issue

1 Answer 1

Your Answer

Sign up or log in

Post as a guest

Not the answer you're looking for? Browse other questions tagged angulartypescriptjestjsangular8monorepo or ask your own question.

Linked

Related

Not the answer you're looking for? Browse other questions tagged
angular
typescript
jestjs
angular8
monorepo
or ask your own question.