angular - 如何对以 HTMLInputElement 作为参数的角度方法进行单元测试？

Question

下面是我的代码片段

代码

applyFilter(event: Event): void {
        const filterValue = (event.target as HTMLInputElement).value;
        this.filterBy = filterValue.trim().toLowerCase();
        this.dataSource.filter = filterValue.trim().toLowerCase();
    }

测试用例

 fit('applyFilter', () => {
        const event = new Event('click');
        component.applyFilter(event);
    });

我得到的错误是“TypeError：无法读取null的属性'值'”，而此转换“（event.target as HTMLInputElement）.value;” 发生提到的错误

标签： angularunit-testingjasmine

Answer 1

I would just mock the object.

it('should change filterBy and dataSource.filter', () => {
  const event = { target: { value: 'hello' } } as any;
  component.applyFilter(event);
  expect(component.filterBy).toBe('hello');
  expect(component.dataSource.filter).toBe('hello');
});