I have a pipe that sanatises HTML as below:
import { Pipe, PipeTransform } from '@angular/core';
import { DomSanitizer } from '@angular/platform-browser';
@Pipe({
name: 'sanitiseHtml'
})
export class SanitiseHtmlPipe implements PipeTransform {
constructor(private _sanitizer: DomSanitizer) {}
transform(value: any): any {
return this._sanitizer.bypassSecurityTrustHtml(value);
}
}
I want to test it as below:
describe('Pipe: Sanatiser', () => {
let pipe: SanitiseHtmlPipe;
beforeEach(() => {
pipe = new SanitiseHtmlPipe(new DomSanitizer());
});
it('create an instance', () => {
expect(pipe).toBeTruthy();
});
});
The DomSanatizer is an abstract class which is autowired by typescript by passing it into a constructor:
constructor(private _sanitizer: DomSanitizer) {}
Currently I get the typescript errror:
Cannot create an instance of the abstract class 'DomSanitizer'.
Does anyone know what typescript does when instantiating dependencies passed into a constructor in Angular? Or what the way to test something like this is?
Because of the DI in your pipe, you need to configure a test environment (test bed) to resolve the dependency:
import { BrowserModule, DomSanitizer } from '@angular/platform-browser';
import { inject, TestBed } from '@angular/core/testing';
describe('SanitiseHtmlPipe', () => {
beforeEach(() => {
TestBed
.configureTestingModule({
imports: [
BrowserModule
]
});
});
it('create an instance', inject([DomSanitizer], (domSanitizer: DomSanitizer) => {
let pipe = new SanitiseHtmlPipe(domSanitizer);
expect(pipe).toBeTruthy();
}));
});