Let's say i have an angular 6 component with a method test
which returns some value:
import { doSomething } from './helper';
@Component({
...
})
export class AppComponent {
test() {
const data = doSomething(1);
return data.something ? 1: 2;
}
}
doSomething
is just a simple helper function:
export function doSomething() {
return { something: 1 };
}
Is it possible to mock or spy this function in a unit test (so i can control its returnValue)? Or do i have to change my approach in the component?
Please note: doSomething()
can be a lodash function, a const, a class etc. I just tried to keep the example as simple as possible.
Things i've tried:
SpyOn
doesn't work because function is not attached to anything
Importing an mock-function into the imports
array of TestBed.configureTestingModule
gives Unexpected value 'doSomething' imported by the module 'DynamicTestModule'. Please add a @NgModule annotation.
Creating a service for it works but it feels silly to have to create services for each imported function
In your spec file import the helper this way:
import * as helper from './helper';
And in your it() you can spy on the helper object and return the requested value:
spyOn(helper, 'doSomething').and.returnValue({});