Angular 5 karma unit test bug - karma-jasmine

Question

When I do karma unit test in Angular5, I have some issues.
Chrome 63.0.3239 (Windows 7 0.0.0): Executed 3 of 29 SUCCESS (0 secs /
2.516 secs) Chrome 63.0.3239 (Windows 7 0.0.0) ERROR Uncaught NetworkError: Failed to execute 'send' on 'XMLHttpRequest': Failed to
load
'ng:///DynamicTestModule/FollowersItemComponent_Host.ngfactory.js'.
Chrome 63.0.3239 (Windows 7 0.0.0) ERROR Uncaught NetworkError:
Failed to execute 'send' on 'XMLHttpRequest': Failed to load
'ng:///DynamicTestModule/FollowersItemComponent_Host.ngfactory.js'.
at http://localhost:9876/_karma_webpack_/polyfills.bundle.js:2281
Chrome 63.0.3239 (Windows 7 0.0.0): Executed 3 of 29 ERROR (0 secs /
2.516 secs) Chrome 63.0.3239 (Windows 7 0.0.0) ERROR Uncaught NetworkError: Failed to execute 'send' on 'XMLHttpRequest': Failed to
load
'ng:///DynamicTestModule/FollowersItemComponent_Host.ngfactory.js'.
Chrome 63.0.3239 (Windows 7 0.0.0): Executed 3 of 29 ERROR (2.546 secs
/ 2.516 secs)
I am not sure why this problem happened.
Please help me. Thanks.

Answer 1

I don't know if you managed this, but this errors could come from any input the component is waiting :)
If you have #Input() in your component, then you need to provide this input in your tests. Usually you can do it in beforeEach method :
beforeEach(() => {
fixture = TestBed.createComponent(YourComponent);
component = fixture.componentInstance;
component.yourInput = 'anyInput'
});