angular-docs-cn/packages/common/test/directives/ng_if_spec.ts

287 lines
11 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {CommonModule, ɵgetDOM as getDOM} from '@angular/common';
import {Component} from '@angular/core';
import {ComponentFixture, TestBed, async} from '@angular/core/testing';
import {By} from '@angular/platform-browser/src/dom/debug/by';
import {expect} from '@angular/platform-browser/testing/src/matchers';
{
describe('ngIf directive', () => {
let fixture: ComponentFixture<any>;
function getComponent(): TestComponent { return fixture.componentInstance; }
afterEach(() => { fixture = null !; });
beforeEach(() => {
TestBed.configureTestingModule({
declarations: [TestComponent],
imports: [CommonModule],
});
});
it('should work in a template attribute', async(() => {
const template = '<span *ngIf="booleanCondition">hello</span>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('hello');
}));
it('should work on a template element', async(() => {
const template = '<ng-template [ngIf]="booleanCondition">hello2</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('hello2');
}));
it('should toggle node when condition changes', async(() => {
const template = '<span *ngIf="booleanCondition">hello</span>';
fixture = createTestComponent(template);
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(0);
expect(fixture.nativeElement).toHaveText('');
getComponent().booleanCondition = true;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('hello');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(0);
expect(fixture.nativeElement).toHaveText('');
}));
it('should handle nested if correctly', async(() => {
const template =
'<div *ngIf="booleanCondition"><span *ngIf="nestedBooleanCondition">hello</span></div>';
fixture = createTestComponent(template);
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(0);
expect(fixture.nativeElement).toHaveText('');
getComponent().booleanCondition = true;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('hello');
getComponent().nestedBooleanCondition = false;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(0);
expect(fixture.nativeElement).toHaveText('');
getComponent().nestedBooleanCondition = true;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('hello');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(0);
expect(fixture.nativeElement).toHaveText('');
}));
it('should update several nodes with if', async(() => {
const template = '<span *ngIf="numberCondition + 1 >= 2">helloNumber</span>' +
'<span *ngIf="stringCondition == \'foo\'">helloString</span>' +
'<span *ngIf="functionCondition(stringCondition, numberCondition)">helloFunction</span>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(3);
expect(fixture.nativeElement.textContent).toEqual('helloNumberhelloStringhelloFunction');
getComponent().numberCondition = 0;
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('helloString');
getComponent().numberCondition = 1;
getComponent().stringCondition = 'bar';
fixture.detectChanges();
expect(fixture.debugElement.queryAll(By.css('span')).length).toEqual(1);
expect(fixture.nativeElement).toHaveText('helloNumber');
}));
it('should not add the element twice if the condition goes from truthy to truthy', async(() => {
const template = '<span *ngIf="numberCondition">hello</span>';
fixture = createTestComponent(template);
fixture.detectChanges();
let els = fixture.debugElement.queryAll(By.css('span'));
expect(els.length).toEqual(1);
getDOM().addClass(els[0].nativeElement, 'marker');
expect(fixture.nativeElement).toHaveText('hello');
getComponent().numberCondition = 2;
fixture.detectChanges();
els = fixture.debugElement.queryAll(By.css('span'));
expect(els.length).toEqual(1);
expect(els[0].nativeElement.classList.contains('marker')).toBe(true);
expect(fixture.nativeElement).toHaveText('hello');
}));
describe('then/else templates', () => {
it('should support else', async(() => {
const template = '<span *ngIf="booleanCondition; else elseBlock">TRUE</span>' +
'<ng-template #elseBlock>FALSE</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('TRUE');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('FALSE');
}));
it('should support then and else', async(() => {
const template =
'<span *ngIf="booleanCondition; then thenBlock; else elseBlock">IGNORE</span>' +
'<ng-template #thenBlock>THEN</ng-template>' +
'<ng-template #elseBlock>ELSE</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('THEN');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('ELSE');
}));
it('should support removing the then/else templates', () => {
const template = `<span *ngIf="booleanCondition;
then nestedBooleanCondition ? tplRef : null;
else nestedBooleanCondition ? tplRef : null"></span>
<ng-template #tplRef>Template</ng-template>`;
fixture = createTestComponent(template);
const comp = fixture.componentInstance;
// then template
comp.booleanCondition = true;
comp.nestedBooleanCondition = true;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('Template');
comp.nestedBooleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('');
// else template
comp.booleanCondition = true;
comp.nestedBooleanCondition = true;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('Template');
comp.nestedBooleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('');
});
it('should support dynamic else', async(() => {
const template =
'<span *ngIf="booleanCondition; else nestedBooleanCondition ? b1 : b2">TRUE</span>' +
'<ng-template #b1>FALSE1</ng-template>' +
'<ng-template #b2>FALSE2</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('TRUE');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('FALSE1');
getComponent().nestedBooleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('FALSE2');
}));
it('should support binding to variable using let', async(() => {
const template = '<span *ngIf="booleanCondition; else elseBlock; let v">{{v}}</span>' +
'<ng-template #elseBlock let-v>{{v}}</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('true');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('false');
}));
it('should support binding to variable using as', async(() => {
const template = '<span *ngIf="booleanCondition as v; else elseBlock">{{v}}</span>' +
'<ng-template #elseBlock let-v>{{v}}</ng-template>';
fixture = createTestComponent(template);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('true');
getComponent().booleanCondition = false;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('false');
}));
});
describe('Type guarding', () => {
it('should throw when then block is not template', async(() => {
const template = '<span *ngIf="booleanCondition; then thenBlock">IGNORE</span>' +
'<div #thenBlock>THEN</div>';
fixture = createTestComponent(template);
expect(() => fixture.detectChanges())
.toThrowError(/ngIfThen must be a TemplateRef, but received/);
}));
it('should throw when else block is not template', async(() => {
const template = '<span *ngIf="booleanCondition; else elseBlock">IGNORE</span>' +
'<div #elseBlock>ELSE</div>';
fixture = createTestComponent(template);
expect(() => fixture.detectChanges())
.toThrowError(/ngIfElse must be a TemplateRef, but received/);
}));
});
});
}
@Component({selector: 'test-cmp', template: ''})
class TestComponent {
booleanCondition: boolean = true;
nestedBooleanCondition: boolean = true;
numberCondition: number = 1;
stringCondition: string = 'foo';
functionCondition: Function = (s: any, n: any): boolean => s == 'foo' && n == 1;
}
function createTestComponent(template: string): ComponentFixture<TestComponent> {
return TestBed.overrideComponent(TestComponent, {set: {template: template}})
.createComponent(TestComponent);
}