PipeTransform ENUM

[elder gulch]

I'm not sure to understand what you want to achieve. But technically, you can use your Pipe in your component.

But it's always better to use it directly in the view

How about <p>{{ item | taskType }}</p> ?

Your pipe is probably wrong

Remove some complexity to isolate the problem

@Pipe({
  name: 'taskType',
})
export class TaskTypePipe implements PipeTransform {
  constructor() {}

  transform(type: TaskType): string {
    switch (type) {
      case TaskType.BMW:
        return `Test BMW`;
      case TaskType.MERCEDES:
        return `Test Mercedes`;
      case TaskType.VOLVO:
        return `Test Volvo`;
      default:
        return 'Unknown task type';
    }
  }
}

public getEnumKeys(): string[] {
  return Object.keys(TaskType);
}

Put a break point in the switch of your pipe to see what happens

Have you added the pipe to your view?
<p>{{ item | taskType }}</p>

How about the break point?

Try to make a Stackblitz cause it's hard to tell without the full context

[strong igloo]

@pale pecan electrochip asked you twice to use the pipe in the template, but there is no pipe used in your Stackblitz example.

[elder gulch]

Here is your working solution https://stackblitz.com/edit/angular-pgndqg-r2bdlh?file=src/app/button-toggle-mode-example.ts (not the best IMHO but it's working)
You forgot to declare your pipe in the module

[strong igloo]

That's already done from the beginning for me.
If you expect something else, take more time to explain your expectations.