import { Component, OnInit } from "@angular/core";
import { of } from "rxjs";

@Component({
    selector: "piped-component",
    template: "<span>{{ value | async }}</span>"
})
export class PipedComponent {
    value = of("foo");
}

@Component({
    selector: "not-piped-component",
    template: "<span>{{ value }}</span>"
})
export class NotPipedComponent implements OnInit {
    value: string;
    ngOnInit() {
        of("foo").subscribe(value => this.value = value);
                  ~~~~~~~~~                     [prefer-async-pipe]
    }
}

[prefer-async-pipe]: Prefer async pipe over subscribe