Provide the ability to test directives that contain input signals without wrapper components

[jamcoupe]

Which @angular/* package(s) are relevant/related to the feature request?

core

Description

Given the following simple directive with a signal input:

@Directive({
  selector: '[appSimple]',
  standalone: true,
  host: {
    '(click)': 'doSomething()',
  }
})
export class SimpleDirective {
  data = input.required<string>();

  doSomething() {
    console.log(this.data());
  }
}

There is no way for me to write a test because I can not use create a "DirectiveFixture"

Proposed solution

Provide a similar approach as TestBed.compileComponents but for directives.

Alternatives considered

Stick with requiring wrapper components to test, but add documentation when input signals become available as part of the public API.

[jamcoupe]

@topdev658 Your example is how I am currently testing signal directives.

This feature request was to not require wrapper component to test signal directives which is what your example does.

[JeanMeche]

My take on this would be that, it doesn't really make sense to test a directive without a HostElement as it would not represent how they behave at runtime.

Depending on your test scenario, it could make sense to extract some logic from your directive into a separate class/function and test it separately.