angular-cn/modules/@angular/common/test/directives/ng_for_spec.ts

388 lines
15 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} from '@angular/common';
import {Component, ContentChild, TemplateRef} 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/matchers';
let thisArg: any;
export function main() {
describe('ngFor', () => {
let fixture: ComponentFixture<any>;
function getComponent(): TestComponent { return fixture.componentInstance; }
function detectChangesAndExpectText(text: string): void {
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText(text);
}
afterEach(() => { fixture = null; });
beforeEach(() => {
TestBed.configureTestingModule({
declarations: [
TestComponent,
ComponentUsingTestComponent,
],
imports: [CommonModule],
});
});
it('should reflect initial elements', async(() => {
fixture = createTestComponent();
detectChangesAndExpectText('1;2;');
}));
it('should reflect added elements', async(() => {
fixture = createTestComponent();
fixture.detectChanges();
getComponent().items.push(3);
detectChangesAndExpectText('1;2;3;');
}));
it('should reflect removed elements', async(() => {
fixture = createTestComponent();
fixture.detectChanges();
getComponent().items.splice(1, 1);
detectChangesAndExpectText('1;');
}));
it('should reflect moved elements', async(() => {
fixture = createTestComponent();
fixture.detectChanges();
getComponent().items.splice(0, 1);
getComponent().items.push(1);
detectChangesAndExpectText('2;1;');
}));
it('should reflect a mix of all changes (additions/removals/moves)', async(() => {
fixture = createTestComponent();
getComponent().items = [0, 1, 2, 3, 4, 5];
fixture.detectChanges();
getComponent().items = [6, 2, 7, 0, 4, 8];
detectChangesAndExpectText('6;2;7;0;4;8;');
}));
it('should iterate over an array of objects', async(() => {
const template = '<ul><li template="ngFor let item of items">{{item["name"]}};</li></ul>';
fixture = createTestComponent(template);
// INIT
getComponent().items = [{'name': 'misko'}, {'name': 'shyam'}];
detectChangesAndExpectText('misko;shyam;');
// GROW
getComponent().items.push({'name': 'adam'});
detectChangesAndExpectText('misko;shyam;adam;');
// SHRINK
getComponent().items.splice(2, 1);
getComponent().items.splice(0, 1);
detectChangesAndExpectText('shyam;');
}));
it('should gracefully handle nulls', async(() => {
const template = '<ul><li template="ngFor let item of null">{{item}};</li></ul>';
fixture = createTestComponent(template);
detectChangesAndExpectText('');
}));
it('should gracefully handle ref changing to null and back', async(() => {
fixture = createTestComponent();
detectChangesAndExpectText('1;2;');
getComponent().items = null;
detectChangesAndExpectText('');
getComponent().items = [1, 2, 3];
detectChangesAndExpectText('1;2;3;');
}));
it('should throw on non-iterable ref and suggest using an array', async(() => {
fixture = createTestComponent();
getComponent().items = <any>'whaaa';
expect(() => fixture.detectChanges())
.toThrowError(
/Cannot find a differ supporting object 'whaaa' of type 'string'. NgFor only supports binding to Iterables such as Arrays/);
}));
it('should throw on ref changing to string', async(() => {
fixture = createTestComponent();
detectChangesAndExpectText('1;2;');
getComponent().items = <any>'whaaa';
expect(() => fixture.detectChanges()).toThrowError();
}));
it('should works with duplicates', async(() => {
fixture = createTestComponent();
const a = new Foo();
getComponent().items = [a, a];
detectChangesAndExpectText('foo;foo;');
}));
it('should repeat over nested arrays', async(() => {
const template = '<div>' +
'<div template="ngFor let item of items">' +
'<div template="ngFor let subitem of item">' +
'{{subitem}}-{{item.length}};' +
'</div>|' +
'</div>' +
'</div>';
fixture = createTestComponent(template);
getComponent().items = [['a', 'b'], ['c']];
detectChangesAndExpectText('a-2;b-2;|c-1;|');
getComponent().items = [['e'], ['f', 'g']];
detectChangesAndExpectText('e-1;|f-2;g-2;|');
}));
it('should repeat over nested arrays with no intermediate element', async(() => {
const template = '<div><template ngFor let-item [ngForOf]="items">' +
'<div template="ngFor let subitem of item">' +
'{{subitem}}-{{item.length}};' +
'</div></template></div>';
fixture = createTestComponent(template);
getComponent().items = [['a', 'b'], ['c']];
detectChangesAndExpectText('a-2;b-2;c-1;');
getComponent().items = [['e'], ['f', 'g']];
detectChangesAndExpectText('e-1;f-2;g-2;');
}));
it('should repeat over nested ngIf that are the last node in the ngFor temlate', async(() => {
const template =
`<div><template ngFor let-item [ngForOf]="items" let-i="index"><div>{{i}}|</div>` +
`<div *ngIf="i % 2 == 0">even|</div></template></div>`;
fixture = createTestComponent(template);
const items = [1];
getComponent().items = items;
detectChangesAndExpectText('0|even|');
items.push(1);
detectChangesAndExpectText('0|even|1|');
items.push(1);
detectChangesAndExpectText('0|even|1|2|even|');
}));
it('should display indices correctly', async(() => {
const template =
'<div><span template="ngFor: let item of items; let i=index">{{i.toString()}}</span></div>';
fixture = createTestComponent(template);
getComponent().items = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
detectChangesAndExpectText('0123456789');
getComponent().items = [1, 2, 6, 7, 4, 3, 5, 8, 9, 0];
detectChangesAndExpectText('0123456789');
}));
it('should display first item correctly', async(() => {
const template =
'<div><span template="ngFor: let item of items; let isFirst=first">{{isFirst.toString()}}</span></div>';
fixture = createTestComponent(template);
getComponent().items = [0, 1, 2];
detectChangesAndExpectText('truefalsefalse');
getComponent().items = [2, 1];
detectChangesAndExpectText('truefalse');
}));
it('should display last item correctly', async(() => {
const template =
'<div><span template="ngFor: let item of items; let isLast=last">{{isLast.toString()}}</span></div>';
fixture = createTestComponent(template);
getComponent().items = [0, 1, 2];
detectChangesAndExpectText('falsefalsetrue');
getComponent().items = [2, 1];
detectChangesAndExpectText('falsetrue');
}));
it('should display even items correctly', async(() => {
const template =
'<div><span template="ngFor: let item of items; let isEven=even">{{isEven.toString()}}</span></div>';
fixture = createTestComponent(template);
getComponent().items = [0, 1, 2];
detectChangesAndExpectText('truefalsetrue');
getComponent().items = [2, 1];
detectChangesAndExpectText('truefalse');
}));
it('should display odd items correctly', async(() => {
const template =
'<div><span template="ngFor: let item of items; let isOdd=odd">{{isOdd.toString()}}</span></div>';
fixture = createTestComponent(template);
getComponent().items = [0, 1, 2, 3];
detectChangesAndExpectText('falsetruefalsetrue');
getComponent().items = [2, 1];
detectChangesAndExpectText('falsetrue');
}));
it('should allow to use a custom template', async(() => {
const tcTemplate =
'<ul><template ngFor [ngForOf]="items" [ngForTemplate]="contentTpl"></template></ul>';
TestBed.overrideComponent(TestComponent, {set: {template: tcTemplate}});
const cutTemplate =
'<test-cmp><li template="let item; let i=index">{{i}}: {{item}};</li></test-cmp>';
TestBed.overrideComponent(ComponentUsingTestComponent, {set: {template: cutTemplate}});
fixture = TestBed.createComponent(ComponentUsingTestComponent);
const testComponent = fixture.debugElement.children[0];
testComponent.componentInstance.items = ['a', 'b', 'c'];
fixture.detectChanges();
expect(testComponent.nativeElement).toHaveText('0: a;1: b;2: c;');
}));
it('should use a default template if a custom one is null', async(() => {
const testTemplate = `<ul><template ngFor let-item [ngForOf]="items"
[ngForTemplate]="contentTpl" let-i="index">{{i}}: {{item}};</template></ul>`;
TestBed.overrideComponent(TestComponent, {set: {template: testTemplate}});
const cutTemplate =
'<test-cmp><li template="let item; let i=index">{{i}}: {{item}};</li></test-cmp>';
TestBed.overrideComponent(ComponentUsingTestComponent, {set: {template: cutTemplate}});
fixture = TestBed.createComponent(ComponentUsingTestComponent);
const testComponent = fixture.debugElement.children[0];
testComponent.componentInstance.items = ['a', 'b', 'c'];
fixture.detectChanges();
expect(testComponent.nativeElement).toHaveText('0: a;1: b;2: c;');
}));
it('should use a custom template when both default and a custom one are present', async(() => {
const testTemplate = `<ul><template ngFor let-item [ngForOf]="items"
[ngForTemplate]="contentTpl" let-i="index">{{i}}=> {{item}};</template></ul>`;
TestBed.overrideComponent(TestComponent, {set: {template: testTemplate}});
const cutTemplate =
'<test-cmp><li template="let item; let i=index">{{i}}: {{item}};</li></test-cmp>';
TestBed.overrideComponent(ComponentUsingTestComponent, {set: {template: cutTemplate}});
fixture = TestBed.createComponent(ComponentUsingTestComponent);
const testComponent = fixture.debugElement.children[0];
testComponent.componentInstance.items = ['a', 'b', 'c'];
fixture.detectChanges();
expect(testComponent.nativeElement).toHaveText('0: a;1: b;2: c;');
}));
describe('track by', () => {
it('should set the context to the component instance', async(() => {
const template =
`<template ngFor let-item [ngForOf]="items" [ngForTrackBy]="trackByContext.bind(this)"></template>`;
fixture = createTestComponent(template);
thisArg = null;
fixture.detectChanges();
expect(thisArg).toBe(getComponent());
}));
it('should not replace tracked items', async(() => {
const template =
`<template ngFor let-item [ngForOf]="items" [ngForTrackBy]="trackById" let-i="index">
<p>{{items[i]}}</p>
</template>`;
fixture = createTestComponent(template);
const buildItemList = () => {
getComponent().items = [{'id': 'a'}];
fixture.detectChanges();
return fixture.debugElement.queryAll(By.css('p'))[0];
};
const firstP = buildItemList();
const finalP = buildItemList();
expect(finalP.nativeElement).toBe(firstP.nativeElement);
}));
it('should update implicit local variable on view', async(() => {
const template =
`<div><template ngFor let-item [ngForOf]="items" [ngForTrackBy]="trackById">{{item['color']}}</template></div>`;
fixture = createTestComponent(template);
getComponent().items = [{'id': 'a', 'color': 'blue'}];
detectChangesAndExpectText('blue');
getComponent().items = [{'id': 'a', 'color': 'red'}];
detectChangesAndExpectText('red');
}));
it('should move items around and keep them updated ', async(() => {
const template =
`<div><template ngFor let-item [ngForOf]="items" [ngForTrackBy]="trackById">{{item['color']}}</template></div>`;
fixture = createTestComponent(template);
getComponent().items = [{'id': 'a', 'color': 'blue'}, {'id': 'b', 'color': 'yellow'}];
detectChangesAndExpectText('blueyellow');
getComponent().items = [{'id': 'b', 'color': 'orange'}, {'id': 'a', 'color': 'red'}];
detectChangesAndExpectText('orangered');
}));
it('should handle added and removed items properly when tracking by index', async(() => {
const template =
`<div><template ngFor let-item [ngForOf]="items" [ngForTrackBy]="trackByIndex">{{item}}</template></div>`;
fixture = createTestComponent(template);
getComponent().items = ['a', 'b', 'c', 'd'];
fixture.detectChanges();
getComponent().items = ['e', 'f', 'g', 'h'];
fixture.detectChanges();
getComponent().items = ['e', 'f', 'h'];
detectChangesAndExpectText('efh');
}));
});
});
}
class Foo {
toString() { return 'foo'; }
}
@Component({selector: 'test-cmp', template: ''})
class TestComponent {
@ContentChild(TemplateRef) contentTpl: TemplateRef<Object>;
items: any[] = [1, 2];
trackById(index: number, item: any): string { return item['id']; }
trackByIndex(index: number, item: any): number { return index; }
trackByContext(): void { thisArg = this; }
}
@Component({selector: 'outer-cmp', template: ''})
class ComponentUsingTestComponent {
items: any = [1, 2];
}
const TEMPLATE = '<div><span template="ngFor let item of items">{{item.toString()}};</span></div>';
function createTestComponent(template: string = TEMPLATE): ComponentFixture<TestComponent> {
return TestBed.overrideComponent(TestComponent, {set: {template: template}})
.createComponent(TestComponent);
}