How can i coverage a promise response with Jasmine and Karma - unit-testing

Question

I have a function that returns and treats a promise, I need to cover the return that is inside then but I don't know how I can do this, I'm currently trying as follows:
confirmRemoveUser(user: IUser) {
this.modalService
.open('Confirma a exclusão do usuário selecionado?', {
titleText: 'Confirmando exclusão',
confirmButtonText: 'Sim',
cancelButtonText: 'Cancelar',
closeButtonText: 'Fechar',
buttonType: 'danger'
})
.result.then(
(result: BentoModalConfirmationCloseReason) => {
if (result === BentoModalConfirmationCloseReason.Confirm) {
if (this.removeUser(user)) {
this.toastService.open('Usuário excluído com sucesso!', { type: 'success', close: true });
} else {
this.toastService.open('Falha ao excluir o usuário!', { type: 'warning', close: true, duration: 0 });
}
}
}
);
}
I'm currently using callthrough () and imagine that with some parameter I can get the promise but I don't know how:
it('Given_ConfirmRemoveUser_When_UserStepIsCalled_Then_UserIsRemoved', (done) => {
component.selectedJob = {
};
component.selectedArea = {
};
component.users = [{
}];
spyOn(modalService, 'open').withArgs('This is modal msg').and.callThrough();
component.confirmRemoveUser(component.users[0]);
expect(modalService.open).toHaveBeenCalled();
done();
});
And my coverage is like the image below:
Image here!
UPDATE
New Error

Answer 1

Your test should work when it is rewritten as follows:
it('Given_ConfirmRemoveUser_When_UserStepIsCalled_Then_UserIsRemoved', (done) => {
spyOn(modalService, 'open').and.returnValue(Promise.resolve(BentoModalConfirmationCloseReason.Confirm));
spyOn(toastService, 'open').and.stub();
component.confirmRemoveUser(component.users[0])
.then(r => {
expect(toastService.open).toHaveBeenCalled();
done();
})
.catch(e => fail(e));
});
You probably also want to know what will be displayed in the toast. Therefore it makes sense to rather use expect(toastService.open).toHaveBeenCalledWith(?);.
UPDATE
Above solution only works if confirmRemoveUser would return a Promise.
confirmRemoveUser(user: IUser) {
return this.modalService
...
In your case, the use of the done function does not make sense. You need to use async and await.
it('Given_ConfirmRemoveUser_When_UserStepIsCalled_Then_UserIsRemoved', async () => {
spyOn(modalService, 'open').and.returnValue(Promise.resolve(BentoModalConfirmationCloseReason.Confirm));
spyOn(toastService, 'open').and.stub();
await component.confirmRemoveUser(component.users[0]);
expect(toastService.open).toHaveBeenCalled();
});
The same can be achieved with fakeAsync and flush.
import { fakeAsync, flush } from '#angular/core/testing';
...
it('Given_ConfirmRemoveUser_When_UserStepIsCalled_Then_UserIsRemoved', fakeAsync(() => {
spyOn(modalService, 'open').and.returnValue(Promise.resolve(BentoModalConfirmationCloseReason.Confirm));
spyOn(toastService, 'open').and.stub();
component.confirmRemoveUser(component.users[0]);
flush();
expect(toastService.open).toHaveBeenCalled();
}));