ERROR: 'NG0303: Can't bind to 'ngbTooltip' since it isn't a known property of 'button'.'

When I run tests locally for my Angular 12 project, I get this error, in all .spec files where ngbTooltip is used I use CUSTOM_ELEMENT_SCHEMA, it is impossible to track the line on which the error occurs. It is noteworthy that the error is absent with ng serve, but appears with ng test. Tell me how to solve this problem, I tried using CUSTOM_ELEMENT_SCHEMA in the application module, it did not help.

Console output Console output 2

ERROR: 'NG0303: Can't bind to 'ngbTooltip' since it isn't a known property of 'button'.'

When I run tests locally for my Angular 12 project, I get this error, in all .spec files where ngbTooltip is used I use CUSTOM_ELEMENT_SCHEMA, it is impossible to track the line on which the error occurs. It is noteworthy that the error is absent with ng serve, but appears with ng test. Tell me how to solve this problem, I tried using CUSTOM_ELEMENT_SCHEMA in the application module, it did not help.

Console output Console output 2

• javascript
• angular
• typescript
• unit-testing
• karma-jasmine

• Just add the CUSTOM_ELEMENT_SCHEMA in the related module.ts file – Aman Gojariya Commented Oct 13, 2021 at 20:08
• It doesn't work, I already said it – Alex Kim Commented Oct 13, 2021 at 20:15

1 Answer 1

Try adding NgbModule to imports array in TestBed.configureTestingModule({.

TestBed.configureTestingModule({
  imports: [NgbModule],
...

If you don't want to import NgbModule or it causes issues in your unit tests, you can mock the directive and provide the mock.

@Directive({
  selector: '[ngbTooltip]'
})
class MockNgbTooltip {}
...
TestBed.configureTestingModule({
  // add the mock to the declarations array
  declarations: [MockNgbTooltip],