Skip to content

docs: update attribute testing guide to include canonical example wit… #69878

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
mfstapert-xip wants to merge 1 commit into
base: main
Choose a base branch
from
+32 −0
Open

docs: update attribute testing guide to include canonical example wit… #69878

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 32 additions & 0 deletions adev/src/content/guide/testing/attribute-directives.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -154,3 +154,35 @@ A few techniques are noteworthy:
The test for the default color uses the injector of the second `<h2>` to get its `Highlight` instance and its `defaultColor`.

- `DebugElement.properties` affords access to the artificial custom property that is set by the directive

## Testing a directive in isolation

A directive can't be constructed through TestBed; it must be rendered through a component's template to behave correctly.
The `Highlight` directive can be tested this way, using a local test component's input to control the directive.

```ts
@Component({
imports: [Highlight],
template: `<p [highlight]="color()">{{ color() }}</p>`,
})
class Test {
readonly color = input('');
}

describe('Highlight', () => {
let fixture: ComponentFixture<Test>;

beforeEach(async () => {
fixture = TestBed.createComponent(Test);
await fixture.whenStable();
});

it('should use the specified color once an input is provided', async () => {
fixture.componentRef.setInput('color', 'blue');
await fixture.whenStable();

const p = fixture.nativeElement.querySelector('p');
expect(p.style.backgroundColor).toBe('blue');
});
});
```
Loading