Type Alias PublicInterface<T>

Extracts only the public members of an interface. This is useful when implementing a class, e.g. when creating a mock of it for tests, so that you do not need to recreate the private and protected members.

class Service {
  protected semiSecretState = 1;
  private secretState = 2;
  doStuff(): void {
    console.log(this.secretState, this.semiSecretState);
  }
}

class MockService implements PublicInterface<Service> {
  doStuffWasCalled = false;
  doStuff(): void {
    this.doStuffWasCalled = true;
  }
}
Copy