angular-docs-cn/packages/core/test/acceptance/pipe_spec.ts

852 lines
26 KiB
TypeScript

/**
* @license
* Copyright Google LLC 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 {ChangeDetectionStrategy, ChangeDetectorRef, Component, Directive, Inject, Injectable, InjectionToken, Input, NgModule, OnChanges, OnDestroy, Pipe, PipeTransform, SimpleChanges, ViewChild, WrappedValue} from '@angular/core';
import {TestBed} from '@angular/core/testing';
import {expect} from '@angular/platform-browser/testing/src/matchers';
import {ivyEnabled} from '@angular/private/testing';
describe('pipe', () => {
@Pipe({name: 'countingPipe'})
class CountingPipe implements PipeTransform {
state: number = 0;
transform(value: any) {
return `${value} state:${this.state++}`;
}
}
@Pipe({name: 'multiArgPipe'})
class MultiArgPipe implements PipeTransform {
transform(value: any, arg1: any, arg2: any, arg3 = 'default') {
return `${value} ${arg1} ${arg2} ${arg3}`;
}
}
it('should support interpolation', () => {
@Component({
template: '{{person.name | countingPipe}}',
})
class App {
person = {name: 'bob'};
}
TestBed.configureTestingModule({declarations: [App, CountingPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('bob state:0');
});
it('should throw if pipe is not found', () => {
@Component({
template: '{{1 | randomPipeName}}',
})
class App {
}
TestBed.configureTestingModule({declarations: [App]});
expect(() => {
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
}).toThrowError(/The pipe 'randomPipeName' could not be found/);
});
it('should support bindings', () => {
@Directive({selector: '[my-dir]'})
class Dir {
@Input() dirProp: string = '';
}
@Pipe({name: 'double'})
class DoublePipe implements PipeTransform {
transform(value: any) {
return `${value}${value}`;
}
}
@Component({
template: `<div my-dir [dirProp]="'a'|double"></div>`,
})
class App {
@ViewChild(Dir) directive!: Dir;
}
TestBed.configureTestingModule({declarations: [App, DoublePipe, Dir]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.componentInstance.directive.dirProp).toBe('aa');
});
it('should support arguments in pipes', () => {
@Component({
template: `{{person.name | multiArgPipe:'one':person.address.city}}`,
})
class App {
person = {name: 'value', address: {city: 'two'}};
}
TestBed.configureTestingModule({declarations: [App, MultiArgPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('value one two default');
});
it('should support calling pipes with different number of arguments', () => {
@Component({
template: `{{person.name | multiArgPipe:'a':'b'}} {{0 | multiArgPipe:1:2:3}}`,
})
class App {
person = {name: 'value'};
}
TestBed.configureTestingModule({declarations: [App, MultiArgPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('value a b default 0 1 2 3');
});
it('should pick a Pipe defined in `declarations` over imported Pipes', () => {
@Pipe({name: 'number'})
class PipeA implements PipeTransform {
transform(value: any) {
return `PipeA: ${value}`;
}
}
@NgModule({
declarations: [PipeA],
exports: [PipeA],
})
class ModuleA {
}
@Pipe({name: 'number'})
class PipeB implements PipeTransform {
transform(value: any) {
return `PipeB: ${value}`;
}
}
@Component({
selector: 'app',
template: '{{ count | number }}',
})
class App {
count = 10;
}
TestBed.configureTestingModule({
imports: [ModuleA],
declarations: [PipeB, App],
});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('PipeB: 10');
});
it('should respect imported module order when selecting Pipe (last imported Pipe is used)',
() => {
@Pipe({name: 'number'})
class PipeA implements PipeTransform {
transform(value: any) {
return `PipeA: ${value}`;
}
}
@NgModule({
declarations: [PipeA],
exports: [PipeA],
})
class ModuleA {
}
@Pipe({name: 'number'})
class PipeB implements PipeTransform {
transform(value: any) {
return `PipeB: ${value}`;
}
}
@NgModule({
declarations: [PipeB],
exports: [PipeB],
})
class ModuleB {
}
@Component({
selector: 'app',
template: '{{ count | number }}',
})
class App {
count = 10;
}
TestBed.configureTestingModule({
imports: [ModuleA, ModuleB],
declarations: [App],
});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('PipeB: 10');
});
it('should do nothing when no change', () => {
let calls: any[] = [];
@Pipe({name: 'identityPipe'})
class IdentityPipe implements PipeTransform {
transform(value: any) {
calls.push(value);
return value;
}
}
@Component({
template: `{{person.name | identityPipe}}`,
})
class App {
person = {name: 'Megatron'};
}
TestBed.configureTestingModule({declarations: [App, IdentityPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(calls).toEqual(['Megatron']);
fixture.detectChanges();
expect(calls).toEqual(['Megatron']);
});
it('should support duplicates by using the later entry', () => {
@Pipe({name: 'duplicatePipe'})
class DuplicatePipe1 implements PipeTransform {
transform(value: any) {
return `${value} from duplicate 1`;
}
}
@Pipe({name: 'duplicatePipe'})
class DuplicatePipe2 implements PipeTransform {
transform(value: any) {
return `${value} from duplicate 2`;
}
}
@Component({
template: '{{person.name | duplicatePipe}}',
})
class App {
person = {name: 'bob'};
}
TestBed.configureTestingModule({declarations: [App, DuplicatePipe1, DuplicatePipe2]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('bob from duplicate 2');
});
it('should support pipe in context of ternary operator', () => {
@Pipe({name: 'pipe'})
class MyPipe implements PipeTransform {
transform(value: any): any {
return value;
}
}
@Component({
template: `{{ condition ? 'a' : 'b' | pipe }}`,
})
class App {
condition = false;
}
TestBed.configureTestingModule({declarations: [App, MyPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('b');
fixture.componentInstance.condition = true;
fixture.detectChanges();
expect(fixture.nativeElement).toHaveText('a');
});
describe('pipes within an optional chain', () => {
it('should not dirty unrelated inputs', () => {
// https://github.com/angular/angular/issues/37194
// https://github.com/angular/angular/issues/37591
// Using a pipe in the LHS of safe navigation operators would clobber unrelated bindings
// iff the pipe returns WrappedValue, incorrectly causing the unrelated binding
// to be considered changed.
const log: string[] = [];
@Component({template: `<my-cmp [value1]="1" [value2]="(value2 | pipe)?.id"></my-cmp>`})
class App {
value2 = {id: 2};
}
@Component({selector: 'my-cmp', template: ''})
class MyCmp {
@Input()
set value1(value1: number) {
log.push(`set value1=${value1}`);
}
@Input()
set value2(value2: number) {
log.push(`set value2=${value2}`);
}
}
@Pipe({name: 'pipe'})
class MyPipe implements PipeTransform {
transform(value: any): any {
log.push('pipe');
return WrappedValue.wrap(value);
}
}
TestBed.configureTestingModule({declarations: [App, MyCmp, MyPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges(/* checkNoChanges */ false);
// Both bindings should have been set. Note: ViewEngine evaluates the pipe out-of-order,
// before setting inputs.
expect(log).toEqual(
ivyEnabled ?
[
'set value1=1',
'pipe',
'set value2=2',
] :
[
'pipe',
'set value1=1',
'set value2=2',
]);
log.length = 0;
fixture.componentInstance.value2 = {id: 3};
fixture.detectChanges(/* checkNoChanges */ false);
// value1 did not change, so it should not have been set.
expect(log).toEqual([
'pipe',
'set value2=3',
]);
});
it('should not include unrelated inputs in ngOnChanges', () => {
// https://github.com/angular/angular/issues/37194
// https://github.com/angular/angular/issues/37591
// Using a pipe in the LHS of safe navigation operators would clobber unrelated bindings
// iff the pipe returns WrappedValue, incorrectly causing the unrelated binding
// to be considered changed.
const log: string[] = [];
@Component({template: `<my-cmp [value1]="1" [value2]="(value2 | pipe)?.id"></my-cmp>`})
class App {
value2 = {id: 2};
}
@Component({selector: 'my-cmp', template: ''})
class MyCmp implements OnChanges {
@Input() value1!: number;
@Input() value2!: number;
ngOnChanges(changes: SimpleChanges): void {
if (changes.value1) {
const {previousValue, currentValue, firstChange} = changes.value1;
log.push(`change value1: ${previousValue} -> ${currentValue} (${firstChange})`);
}
if (changes.value2) {
const {previousValue, currentValue, firstChange} = changes.value2;
log.push(`change value2: ${previousValue} -> ${currentValue} (${firstChange})`);
}
}
}
@Pipe({name: 'pipe'})
class MyPipe implements PipeTransform {
transform(value: any): any {
log.push('pipe');
return WrappedValue.wrap(value);
}
}
TestBed.configureTestingModule({declarations: [App, MyCmp, MyPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges(/* checkNoChanges */ false);
// Both bindings should have been included in ngOnChanges.
expect(log).toEqual([
'pipe',
'change value1: undefined -> 1 (true)',
'change value2: undefined -> 2 (true)',
]);
log.length = 0;
fixture.componentInstance.value2 = {id: 3};
fixture.detectChanges(/* checkNoChanges */ false);
// value1 did not change, so it should not have been included in ngOnChanges
expect(log).toEqual([
'pipe',
'change value2: 2 -> 3 (false)',
]);
});
});
describe('pure', () => {
it('should call pure pipes only if the arguments change', () => {
@Component({
template: '{{person.name | countingPipe}}',
})
class App {
person = {name: null as string | null};
}
TestBed.configureTestingModule({declarations: [App, CountingPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
// change from undefined -> null
fixture.componentInstance.person.name = null;
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('null state:0');
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('null state:0');
// change from null -> some value
fixture.componentInstance.person.name = 'bob';
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('bob state:1');
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('bob state:1');
// change from some value -> some other value
fixture.componentInstance.person.name = 'bart';
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('bart state:2');
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toEqual('bart state:2');
});
});
describe('impure', () => {
let impurePipeInstances: CountingImpurePipe[] = [];
@Pipe({name: 'countingImpurePipe', pure: false})
class CountingImpurePipe implements PipeTransform {
state: number = 0;
transform(value: any) {
return `${value} state:${this.state++}`;
}
constructor() {
impurePipeInstances.push(this);
}
}
beforeEach(() => impurePipeInstances = []);
afterEach(() => impurePipeInstances = []);
it('should call impure pipes on each change detection run', () => {
@Component({
template: '{{person.name | countingImpurePipe}}',
})
class App {
person = {name: 'bob'};
}
TestBed.configureTestingModule({declarations: [App, CountingImpurePipe]});
const fixture = TestBed.createComponent(App);
const pipe = impurePipeInstances[0];
spyOn(pipe, 'transform').and.returnValue('');
expect(pipe.transform).not.toHaveBeenCalled();
fixture.detectChanges();
expect(pipe.transform).toHaveBeenCalledTimes(2);
fixture.detectChanges();
expect(pipe.transform).toHaveBeenCalledTimes(4);
});
it('should not cache impure pipes', () => {
@Component({
template: `
<div [id]="0 | countingImpurePipe">{{1 | countingImpurePipe}}</div>
<div [id]="2 | countingImpurePipe">{{3 | countingImpurePipe}}</div>
`,
})
class App {
}
TestBed.configureTestingModule({declarations: [App, CountingImpurePipe]});
TestBed.createComponent(App);
expect(impurePipeInstances.length).toEqual(4);
expect(impurePipeInstances[0]).toBeAnInstanceOf(CountingImpurePipe);
expect(impurePipeInstances[1]).toBeAnInstanceOf(CountingImpurePipe);
expect(impurePipeInstances[1]).not.toBe(impurePipeInstances[0]);
expect(impurePipeInstances[2]).toBeAnInstanceOf(CountingImpurePipe);
expect(impurePipeInstances[2]).not.toBe(impurePipeInstances[0]);
expect(impurePipeInstances[3]).toBeAnInstanceOf(CountingImpurePipe);
expect(impurePipeInstances[3]).not.toBe(impurePipeInstances[0]);
});
});
describe('lifecycles', () => {
it('should call ngOnDestroy on pipes', () => {
let destroyCalls = 0;
@Pipe({name: 'pipeWithOnDestroy'})
class PipeWithOnDestroy implements PipeTransform, OnDestroy {
ngOnDestroy() {
destroyCalls++;
}
transform(value: any): any {
return null;
}
}
@Component({
template: '{{1 | pipeWithOnDestroy}}',
})
class App {
}
TestBed.configureTestingModule({declarations: [App, PipeWithOnDestroy]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
fixture.destroy();
expect(destroyCalls).toBe(1);
});
});
describe('injection mechanism', () => {
it('should be able to handle Service injection', () => {
@Injectable()
class Service {
title = 'Service Title';
}
@Pipe({name: 'myConcatPipe'})
class ConcatPipe implements PipeTransform {
constructor(public service: Service) {}
transform(value: string): string {
return `${value} - ${this.service.title}`;
}
}
@Component({
template: '{{title | myConcatPipe}}',
})
class App {
title = 'MyComponent Title';
}
TestBed.configureTestingModule({declarations: [App, ConcatPipe], providers: [Service]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('MyComponent Title - Service Title');
});
it('should be able to handle Token injections', () => {
class Service {
title = 'Service Title';
}
const token = new InjectionToken<Service>('service token');
@Pipe({name: 'myConcatPipe'})
class ConcatPipe implements PipeTransform {
constructor(@Inject(token) public service: Service) {}
transform(value: string): string {
return `${value} - ${this.service.title}`;
}
}
@Component({
template: '{{title | myConcatPipe}}',
})
class App {
title = 'MyComponent Title';
}
TestBed.configureTestingModule({
declarations: [App, ConcatPipe],
providers: [{provide: token, useValue: new Service()}]
});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('MyComponent Title - Service Title');
});
it('should be able to handle Module injection', () => {
@Injectable()
class Service {
title = 'Service Title';
}
@NgModule({providers: [Service]})
class SomeModule {
}
@Pipe({name: 'myConcatPipe'})
class ConcatPipe implements PipeTransform {
constructor(public service: Service) {}
transform(value: string): string {
return `${value} - ${this.service.title}`;
}
}
@Component({
template: '{{title | myConcatPipe}}',
})
class App {
title = 'MyComponent Title';
}
TestBed.configureTestingModule({declarations: [App, ConcatPipe], imports: [SomeModule]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('MyComponent Title - Service Title');
});
it('should inject the ChangeDetectorRef of the containing view when using pipe inside a component input',
() => {
let pipeChangeDetectorRef: ChangeDetectorRef|undefined;
@Component({
changeDetection: ChangeDetectionStrategy.OnPush,
selector: 'some-comp',
template: 'Inner value: "{{displayValue}}"',
})
class SomeComp {
@Input() value: any;
displayValue = 0;
}
@Component({
changeDetection: ChangeDetectionStrategy.OnPush,
template: `
<some-comp [value]="pipeValue | testPipe"></some-comp>
Outer value: "{{displayValue}}"
`,
})
class App {
@Input() something: any;
@ViewChild(SomeComp) comp!: SomeComp;
pipeValue = 10;
displayValue = 0;
}
@Pipe({name: 'testPipe'})
class TestPipe implements PipeTransform {
constructor(changeDetectorRef: ChangeDetectorRef) {
pipeChangeDetectorRef = changeDetectorRef;
}
transform() {
return '';
}
}
TestBed.configureTestingModule({declarations: [App, SomeComp, TestPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
fixture.componentInstance.displayValue = 1;
fixture.componentInstance.comp.displayValue = 1;
pipeChangeDetectorRef!.markForCheck();
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toContain('Outer value: "1"');
expect(fixture.nativeElement.textContent).toContain('Inner value: "0"');
});
it('should inject the ChangeDetectorRef of the containing view when using pipe inside a component input which has child nodes',
() => {
let pipeChangeDetectorRef: ChangeDetectorRef|undefined;
@Component({
changeDetection: ChangeDetectionStrategy.OnPush,
selector: 'some-comp',
template: 'Inner value: "{{displayValue}}" <ng-content></ng-content>',
})
class SomeComp {
@Input() value: any;
displayValue = 0;
}
@Component({
changeDetection: ChangeDetectionStrategy.OnPush,
template: `
<some-comp [value]="pipeValue | testPipe">
<div>Hello</div>
</some-comp>
Outer value: "{{displayValue}}"
`,
})
class App {
@Input() something: any;
@ViewChild(SomeComp) comp!: SomeComp;
pipeValue = 10;
displayValue = 0;
}
@Pipe({name: 'testPipe'})
class TestPipe implements PipeTransform {
constructor(changeDetectorRef: ChangeDetectorRef) {
pipeChangeDetectorRef = changeDetectorRef;
}
transform() {
return '';
}
}
TestBed.configureTestingModule({declarations: [App, SomeComp, TestPipe]});
const fixture = TestBed.createComponent(App);
fixture.detectChanges();
fixture.componentInstance.displayValue = 1;
fixture.componentInstance.comp.displayValue = 1;
pipeChangeDetectorRef!.markForCheck();
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toContain('Outer value: "1"');
expect(fixture.nativeElement.textContent).toContain('Inner value: "0"');
});
});
describe('pure pipe error handling', () => {
it('should not re-invoke pure pipes if it fails initially', () => {
@Pipe({name: 'throwPipe', pure: true})
class ThrowPipe implements PipeTransform {
transform(): never {
throw new Error('ThrowPipeError');
}
}
@Component({template: `{{val | throwPipe}}`})
class App {
val = 'anything';
}
const fixture =
TestBed.configureTestingModule({declarations: [App, ThrowPipe]}).createComponent(App);
// first invocation
expect(() => fixture.detectChanges()).toThrowError(/ThrowPipeError/);
// second invocation - should not throw
fixture.detectChanges();
});
it('should display the last known result from a pure pipe when it throws', () => {
@Pipe({name: 'throwPipe', pure: true})
class ThrowPipe implements PipeTransform {
transform(value: string): string {
if (value === 'KO') {
throw new Error('ThrowPipeError');
} else {
return value;
}
}
}
@Component({template: `{{val | throwPipe}}`})
class App {
val = 'anything';
}
const fixture =
TestBed.configureTestingModule({declarations: [App, ThrowPipe]}).createComponent(App);
// first invocation - no error thrown
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('anything');
// second invocation when the error is thrown
fixture.componentInstance.val = 'KO';
expect(() => fixture.detectChanges()).toThrowError(/ThrowPipeError/);
expect(fixture.nativeElement.textContent).toBe('anything');
// third invocation with no changes to input - should not thrown and preserve the last known
// results
fixture.detectChanges();
expect(fixture.nativeElement.textContent).toBe('anything');
});
describe('pure pipe error handling with multiple arguments', () => {
const args: string[] = new Array(10).fill(':0');
for (let numberOfPipeArgs = 0; numberOfPipeArgs < args.length; numberOfPipeArgs++) {
it(`should not invoke ${
numberOfPipeArgs} argument pure pipe second time if it throws unless input changes`,
() => {
// https://stackblitz.com/edit/angular-mbx2pg
const log: string[] = [];
@Pipe({name: 'throw', pure: true})
class ThrowPipe implements PipeTransform {
transform(): never {
log.push('throw');
throw new Error('ThrowPipeError');
}
}
@Component({template: `{{val | throw${args.slice(0, numberOfPipeArgs).join('')}}}`})
class App {
val = 'anything';
}
const fixture = TestBed.configureTestingModule({declarations: [App, ThrowPipe]})
.createComponent(App);
// First invocation of detect changes should throw.
expect(() => fixture.detectChanges()).toThrowError(/ThrowPipeError/);
expect(log).toEqual(['throw']);
// Second invocation should not throw as input to the `throw` pipe has not changed and
// the pipe is pure.
log.length = 0;
expect(() => fixture.detectChanges()).not.toThrow();
expect(log).toEqual([]);
fixture.componentInstance.val = 'change';
// First invocation of detect changes should throw because the input changed.
expect(() => fixture.detectChanges()).toThrowError(/ThrowPipeError/);
expect(log).toEqual(['throw']);
// Second invocation should not throw as input to the `throw` pipe has not changed and
// the pipe is pure.
log.length = 0;
expect(() => fixture.detectChanges()).not.toThrow();
expect(log).toEqual([]);
});
}
});
});
});