Jasmine Angular 9 test failing because 'unreachable' stack trace at injectableDefOrInjectorDefFactory

Question

I created an Angular application under 4. I have migrated from version to version and am currently latest version 9. I was reviewing my tests. I have a Login component th

Answer 1

providers: [
    ...
    { provide: UserService, useClass: userServiceSpy }
]

Should be changed to:

providers: [
    ...
    { provide: UserService, useValue: userServiceSpy }
]