问题描述
ngOnChanges(): void {
if (this.isCustomer) {
let sectioncopy = [...this.sections];
this.sectionsNotFilled = sectioncopy.find(section => section.filled === false);
...
}
}
我在很多资源上都看到,为了触发ngOnChanges,我必须使用fixture.detectChanges();
,但是我仍然无法测试并在测试中得到错误的结果:
...
let component: XXX;
let fixture: ComponentFixture<XXX>;
...
const sections = [
{
key: 'SECTION1',name: 'Section 1',filled: true
},{
key: 'SECTION2',name: 'Section 2',filled: false
}
];
...
it('should do test',() => {
const sectionsMock = {...sections};
component.sections = sectionsMock;
component.isCustomer = true;
console.log(component.sections); => section are here
//trigger
fixture.detectChanges();
console.log(component.sectionsNotFilled);
expect(component.sectionsNotFilled).toBe(true); => return false :/
});
有什么想法吗?我做错什么了吗?
解决方法
ngOnChanges
是在 第一个 fixture.detectChanges()
而不是随后的那个触发的。
beforeEach(() => {
fixture = TestBed.createComponent(XXX);
component = fixture.componentInstance;
const sectionsMock = {...sections};
component.sections = sectionsMock;
component.isCustomer = true; // set isCustomer = true here
fixture.detectChanges(); // call fixture.detectChanges() here to go to ngOnChanges()
// and the line above will ensure that it goes inside of the if block
});
it('should do test',() => {
expect(component.sectionsNotFilled).toBeTruthy(); // I think you need toBeTruthy() here
// because I think sectionsNotFilled resolves into an object.
});