Jasmine：当测试返回 SPEC 没有预期？

Question

i have this test that returns "SPEC HAS NOT EXPECTATION" without fails, do you have any idea? maybe i am not following the best practice;

 editComponent has been declared into the Test.bed  into the declaration[]

it('test', fakeAsync(() => {
        fixture.whenStable().then(() => {
            editComponent = component.editComponent;
            editComponent.ruleForm = new FormGroup({
                title: new FormControl('test field'),
                cause: new FormControl('test field'),
            });
            fixture.detectChanges();
            spyOn(ruleEditComponent, 'updateRule').withArgs(activeIssueId);
            component.saveRuleDetails(activeIssueId);
            expect(editComponent.createRule).toHaveBeenCalledWith(activeIssueId);
        });

    }));

When a test return SPEC HAS NOT EXPECTATION?

Answer 1

fixture.whenStable returns a Promise and it's result is handled asynchronously. Therefore the unit test ends even before any expect is invoked.

fakeAsync must be used together with tick or flush in order to simulate asynchronous processing in a synchronous way. Try to rewrite your test as follows.

it('test', fakeAsync(() => {
    fixture.whenStable().then(() => {
        editComponent = component.editComponent;
        editComponent.ruleForm = new FormGroup({
            title: new FormControl('test field'),
            cause: new FormControl('test field'),
        });
        fixture.detectChanges();
        spyOn(ruleEditComponent, 'updateRule').withArgs(activeIssueId);
        component.saveRuleDetails(activeIssueId);        
    });
    tick();
    expect(editComponent.createRule).toHaveBeenCalledWith(activeIssueId);
}));

Alternatively you can use the done function as follows.

it('test', (done) => {
    fixture.whenStable().then(() => {
        editComponent = component.editComponent;
        editComponent.ruleForm = new FormGroup({
            title: new FormControl('test field'),
            cause: new FormControl('test field'),
        });
        fixture.detectChanges();
        spyOn(ruleEditComponent, 'updateRule').withArgs(activeIssueId);
        component.saveRuleDetails(activeIssueId);        
        expect(editComponent.createRule).toHaveBeenCalledWith(activeIssueId);
        done();
    });        
}));