Which @angular/* package(s) are the source of the bug?
core
Is this a regression?
Yes
Description
Trying to stub a single component with TestBed.overrideComponent seems to break imports of modules.
I think this is a regression and may have to do with the new vitest builder as I encountered this while migrating a project from jest to vitest. I.e. this used to work in the jest tests.
Or maybe I'm just doing something wrong / haven't fully understood how overrideComponent works, but it's at least unintuitive.
Reproduction
Plain, fresh generated Angular 21 project. No specific vitest configuration or similar.
// app.ts
import { Component, NgModule } from '@angular/core';
@Component({
selector: 'test-component-1',
template: '',
})
export class TestComponent1 {}
@NgModule({
imports: [TestComponent1],
exports: [TestComponent1],
})
export class TestModule1 {}
@Component({
selector: 'test-component-2',
template: '',
})
export class TestComponent2 {}
@Component({
selector: 'app-root',
imports: [TestModule1, TestComponent2],
template: `
<test-component-1></test-component-1>
<test-component-2></test-component-2>
`,
})
export class App {}// app.spec.ts
import { Component } from '@angular/core';
import { TestBed } from '@angular/core/testing';
import { App, TestComponent2 } from './app';
@Component({
selector: 'test-component-2',
template: '',
// avoid NG0912
host: { 'some-binding': 'some-value' },
})
class TestComponent2Mock {}
describe('App', () => {
beforeEach(async () => {
await TestBed.configureTestingModule({
imports: [App],
})
.overrideComponent(App, {
remove: { imports: [TestComponent2] },
add: { imports: [TestComponent2Mock] },
})
.compileComponents();
});
it('should create', () => {
expect(TestBed.createComponent(App)).toBeTruthy();
});
});Running ng test on this project will result in the error
Error: NG0304: 'test-component-1' is not a known element (used in the '_App' component template):
1. If 'test-component-1' is an Angular component, then verify that it is included in the '@Component.imports' of this component.
2. If 'test-component-1' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@Component.schemas' of this component to suppress this message.
The same error occurs when doing
.overrideComponent(App, {
set: { imports: [TestModule1, TestComponent2Mock] },
})or even just
.overrideComponent(App, {})This does not occur if App imports TestComponent1 directly instead of via the module.
Please provide a link to a minimal reproduction of the bug
No response
Please provide the exception or error you saw
Please provide the environment you discovered this bug in (run ng version)
_ _ ____ _ ___
/ \ _ __ __ _ _ _| | __ _ _ __ / ___| | |_ _|
/ △ \ | '_ \ / _` | | | | |/ _` | '__| | | | | | |
/ ___ \| | | | (_| | |_| | | (_| | | | |___| |___ | |
/_/ \_\_| |_|\__, |\__,_|_|\__,_|_| \____|_____|___|
|___/
Angular CLI : 21.2.8
Angular : 21.2.10
Node.js : 24.15.0
Package Manager : npm 10.9.4
Operating System : win32 x64
┌───────────────────────────┬───────────────────┬───────────────────┐
│ Package │ Installed Version │ Requested Version │
├───────────────────────────┼───────────────────┼───────────────────┤
│ @angular/build │ 21.2.8 │ ^21.2.7 │
│ @angular/cli │ 21.2.8 │ ^21.2.7 │
│ @angular/common │ 21.2.10 │ ^21.2.0 │
│ @angular/compiler │ 21.2.10 │ ^21.2.0 │
│ @angular/compiler-cli │ 21.2.10 │ ^21.2.0 │
│ @angular/core │ 21.2.10 │ ^21.2.0 │
│ @angular/forms │ 21.2.10 │ ^21.2.0 │
│ @angular/platform-browser │ 21.2.10 │ ^21.2.0 │
│ @angular/router │ 21.2.10 │ ^21.2.0 │
│ rxjs │ 7.8.2 │ ~7.8.0 │
│ typescript │ 5.9.3 │ ~5.9.2 │
│ vitest │ 4.1.5 │ ^4.0.8 │
└───────────────────────────┴───────────────────┴───────────────────┘
Anything else?
No response
Which @angular/* package(s) are the source of the bug?
core
Is this a regression?
Yes
Description
Trying to stub a single component with
TestBed.overrideComponentseems to break imports of modules.I think this is a regression and may have to do with the new vitest builder as I encountered this while migrating a project from jest to vitest. I.e. this used to work in the jest tests.
Or maybe I'm just doing something wrong / haven't fully understood how
overrideComponentworks, but it's at least unintuitive.Reproduction
Plain, fresh generated Angular 21 project. No specific vitest configuration or similar.
Running ng test on this project will result in the error
The same error occurs when doing
or even just
This does not occur if
AppimportsTestComponent1directly instead of via the module.Please provide a link to a minimal reproduction of the bug
No response
Please provide the exception or error you saw
Please provide the environment you discovered this bug in (run
ng version)Anything else?
No response