我创建了一个Angular Directive,它使用CSS选择器自动修剪我的应用程序中的输入,它看起来像......
import { Directive, HostListener, forwardRef } from '@angular/core';
import { DefaultValueAccessor, NG_VALUE_ACCESSOR } from '@angular/forms';
export const TRIM_VALUE_ACCESSOR: any = {
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => TrimInputDirective),
multi: true
};
/**
* The trim accessor for writing trimmed value and listening to changes that is
* used by the {@link NgModel}, {@link FormControlDirective}, and
* {@link FormControlName} directives.
*/
/* tslint:disable */
@Directive({
selector: `
input
:not([type=checkbox])
:not([type=radio])
:not([type=password])
:not([readonly])
:not(.ng-trim-ignore)
[formControlName],
input
:not([type=checkbox])
:not([type=radio])
:not([type=password])
:not([readonly])
:not(.ng-trim-ignore)
[formControl],
input
:not([type=checkbox])
:not([type=radio])
:not([type=password])
:not([readonly])
:not(.ng-trim-ignore)
[ngModel],
textarea
:not([readonly])
:not(.ng-trim-ignore)
[formControlName],
textarea
:not([readonly])
:not(.ng-trim-ignore)
[formControl],
textarea
:not([readonly])
:not(.ng-trim-ignore)[ngModel],
:not([readonly])
:not(.ng-trim-ignore)
[ngDefaultControl]'
`,
providers: [ TRIM_VALUE_ACCESSOR ]
})
/* tslint:enable */
export class TrimInputDirective extends DefaultValueAccessor {
protected _onTouched: any;
/**
* ngOnChange - Lifecycle hook that is called when any data-bound property of a directive changes.
* @param {string} val - trim value onChange.
*/
@HostListener('input', ['$event.target.value'])
public ngOnChange = (val: string) => {
this.onChange(val.trim());
}
/**
* applyTrim - trims the passed value
* @param {string} val - passed value.
*/
@HostListener('blur', ['$event.target.value'])
public applyTrim(val: string) {
this.writeValue(val.trim());
this._onTouched();
}
/**
* writeValue - trims the passed value
* @param {any} value - passed value.
*/
public writeValue(value: any): void {
if (typeof value === 'string') {
value = value.trim();
}
super.writeValue(value);
}
/**
* registerOnTouched Registers a callback function that should be called when the control receives a blur event.
* @param {function} fn - The user information.
*/
public registerOnTouched(fn: any): void {
this._onTouched = fn;
}
}
现在做一个好的开发人员我必须对一些单元测试...所以我开始把文件放在一起,就在这里
import {Component} from '@angular/core';
import {async, ComponentFixture, TestBed} from '@angular/core/testing';
import {By} from '@angular/platform-browser';
import {TrimInputDirective} from './trim-input.directive';
import {expect} from 'chai';
@Component({
selector: 'my-directive-test-component',
template: ''
})
class TestComponent {
}
describe('Trim Directive', () => {
let fixture: ComponentFixture<TestComponent>;
let inputDebugElement: any;
let directive: TrimInputDirective;
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [
TestComponent,
TrimInputDirective
],
providers: []
}).overrideComponent(TestComponent, {
set: {
template: '<input type="text">'
}
}).compileComponents().then(() => {
fixture = TestBed.createComponent(TestComponent);
fixture.detectChanges();
inputDebugElement = fixture.debugElement.query(By.css('input'));
directive = inputDebugElement.injector.get(TrimInputDirective);
});
}));
it('should trim the input', () => {
directive.ngOnChange(' 1234.56 ')
expect('1234.56').to.be('1234.56'); // I know this isn't the correct test... I will amend this
});
});
现在我希望运行我的测试只是为了确保spec文件中的设置是正确的,但是我收到以下错误:
HeadlessChrome 0.0.0(Mac OS X 10.12.6)修剪指令“在每个”挂钩之前“应修剪输入”FAILED未捕获(在承诺中):错误:StaticInjectorError(DynamicTestModule)[TrimInputDirective]:StaticInjectorError(Platform:core) [TrimInputDirective]:NullInjectorError:没有TrimInputDirective的提供者!错误:StaticInjectorError(DynamicTestModule)[TrimInputDirective]:
我不明白为什么我得到这个错误,为什么我必须提供指令?我不认为这是必要的,如果我必须提供我提供的内容吗?提供实际指令不起作用/解决错误?我很迷茫 . 如果有人能告诉我如何解决问题或为什么我得到它,我将非常感激 .
请注意,这是一个传统的Angular应用程序,是在AngularCLI可用之前构建的 . 所以它有点不正统(例如它不使用Jasmin) .
2 回答
1)您不需要提供您的指令,您只需要在
TestingModule
中声明它 . 然后,它将在具有相应选择器的模板中使用 .2)您的选择器与输入中使用的选择器不对应 . 如果要将其应用于某些类型的所有输入或更改测试,请删除
formControlName
.3)指令在某些事件中被触发 . 您需要模拟这些事件才能看到效果 . 看看这个简化的例子 . (Stackblitz)
而且测试:
您必须在
TestComponent
中提供类似的指令