f5c8e0989d
## Inheritance Semantics:
Decorators:
1) list the decorators of the class and its parents in the ancestor first order
2) only use the last decorator of each kind (e.g. @Component / ...)
Constructor parameters:
If a class inherits from a parent class and does not declare
a constructor, it inherits the parent class constructor,
and with it the parameter metadata of that parent class.
Lifecycle hooks:
Follow the normal class inheritance model,
i.e. lifecycle hooks of parent classes will be called
even if the method is not overwritten in the child class.
## Example
E.g. the following is a valid use of inheritance and it will
also inherit all metadata:
```
@Directive({selector: 'someDir'})
class ParentDirective {
constructor(someDep: SomeDep) {}
ngOnInit() {}
}
class ChildDirective extends ParentDirective {}
```
Closes #11606
Closes #12892
53 lines
1.4 KiB
TypeScript
53 lines
1.4 KiB
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import {PipeResolver} from '@angular/compiler/src/pipe_resolver';
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import {Pipe} from '@angular/core/src/metadata';
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import {stringify} from '../src/facade/lang';
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@Pipe({name: 'somePipe', pure: true})
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class SomePipe {
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}
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class SimpleClass {}
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export function main() {
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describe('PipeResolver', () => {
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let resolver: PipeResolver;
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beforeEach(() => { resolver = new PipeResolver(); });
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it('should read out the metadata from the class', () => {
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const moduleMetadata = resolver.resolve(SomePipe);
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expect(moduleMetadata).toEqual(new Pipe({name: 'somePipe', pure: true}));
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});
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it('should throw when simple class has no pipe decorator', () => {
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expect(() => resolver.resolve(SimpleClass))
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.toThrowError(`No Pipe decorator found on ${stringify(SimpleClass)}`);
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});
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it('should support inheriting the metadata', function() {
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@Pipe({name: 'p'})
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class Parent {
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}
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class ChildNoDecorator extends Parent {}
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@Pipe({name: 'c'})
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class ChildWithDecorator extends Parent {
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}
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expect(resolver.resolve(ChildNoDecorator)).toEqual(new Pipe({name: 'p'}));
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expect(resolver.resolve(ChildWithDecorator)).toEqual(new Pipe({name: 'c'}));
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});
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});
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}
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