Angular16管道pipe问题?

想用一下管道，这是哪里出了问题？1.pipe

import { Pipe, PipeTransform } from '@angular/core';
import { Category } from '../interface';

@Pipe({name: 'category'})
export class CategoryPipe implements PipeTransform {
    transform(value: number): string {
        return Category(value)
    }
}

1. interface

export interface Todo {
    id: number;
    description: string;
    category: number;
    content: string;
}

export enum Category {
    html,
    css,
    js
}