Question

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，它看起来像是......

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;
  }
}

现在我是一名优秀的开发人员，我必须对一些单元测试...所以我开始把文件放在一起，这里是

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＆＃34;在每个＆＃34;之前   勾选＆＃34;应修剪输入＆＃34; FAILED未捕获（承诺）：错误：   StaticInjectorError（DynamicTestModule）[TrimInputDirective]：
  StaticInjectorError（Platform：core）[TrimInputDirective]：         NullInjectorError：没有TrimInputDirective的提供者！错误：StaticInjectorError（DynamicTestModule）[TrimInputDirective]：

我不明白为什么会收到此错误，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？提供实际指令并不能解决错误？我很迷茫。如果有人能告诉我如何解决这个问题或为什么我能得到它，我将非常感激。

请注意，这是一个传统的Angular应用程序，是在之前构建的 AngularCLI可用。所以它有点不正统（例如它不使用Jasmin）。

Answer 1

1）您无需提供指令，只需在TestingModule中声明即可。然后，它将在模板中与相应的选择器一起使用。

2）您的选择器与输入中使用的选择器不对应。如果您希望将其应用于某些类型的所有输入或更改测试，请移除formControlName。

input
    :not([type=checkbox])
    :not([type=radio])
    :not([type=password])
    :not([readonly])
    :not(.ng-trim-ignore)
    [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）

@Directive({
  selector: `
    input
    :not([type=checkbox])
    :not([type=radio])
    :not([type=password])
    :not([readonly])
    :not(.ng-trim-ignore)
  `
})
export class TrimInputDirective {
  constructor(private el: ElementRef) { }

  @HostListener('blur') onLeave() {
   if (this.el.nativeElement.value)
    this.el.nativeElement.value = this.el.nativeElement.value.trim();
  }

}

测试：

describe('Trim Directive', () => {
  let fixture: ComponentFixture<TestComponent>;
  let inputDebugElement: any;
  let directive: TrimInputDirective;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [
        TestComponent,
        TrimInputDirective
      ],
      imports: [FormsModule],
      providers: []
    }).overrideComponent(TestComponent, {
      set: {
        template: '<input type="text">'
      }
    }).compileComponents().then(() => {
      fixture = TestBed.createComponent(TestComponent);
      inputDebugElement = fixture.debugElement.query(By.css('input')).nativeElement;
                                                                      ^^^^^^^^^^^^
    }); 
  }));

  it('should trim the input', () => {
    inputDebugElement.value = '     1234.56     ';
    inputDebugElement.dispatchEvent(new Event('blur'));
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    fixture.detectChanges();
    expect(inputDebugElement.value).toBe('1234.56'); 
  });
});

Answer 2

您必须在SQLExec(Req, "REQ1")// SQLInfoGene("REQ1") SI QRY_2 = Faux 1LORS Info("InfoReqerror execution de la requête : " + SQL.MesErreur) SINON Info("Nombre de colonnes : " + SQL.NbLine) FIN SQLFerme("REQ1")这样的内容中提供指令

TestComponent

角度测试错误 - NullInjectorError：没有TrimInputDirective的提供者

2 个答案: