Should isEmpty consider "empty" SafeString?

[lifeart]

If we use builtin isEmpty on empty SafeString instance, we getting incorrect result.

import { htmlSafe } from '@ember/template';
import { isEmpty } from '@ember/utils';

isEmpty(htmlSafe('')) === false

Wondering if we should update isEmpty to support SafeString...

Real life use case for error:

{{#if (isEmpty this.someEmptySafeString)}}
    it's not rendered, but ideally it should be
{{/if}}

Reproduction: https://limber.glimdown.com/edit?c=AYjmCsGcAIBsEsBuBTaAHATsx9kHcAoeAWzQHsMAXaAYTNLIDtlHqAzDe6AcgAFQExYsgwB6AMb1yzVtwDcRBlWgBvaAAtKxWAGUAhm1QBfaBy59kxAEYjRlS2lh778xeWVr4kAKKlKAT2gTM2IeXksbMQBXSnhYSFcCZAAPd2oAE2Q2PSjYanEnSBgACWRYWDIAdQpYdOgU%2B0Z0mDoGGWoVAgJoer9-fUMdSgx4RlBoAF4NLV0DZAAKbm4ASgUexiZfNACB5CGRscnp7V3FjcotgJWFbuhQZGovS-65-dHQeeXVW56sSiiMIxoE8%2BvNKOovAA6Bw7V7Dd6rW5GLo9AA89lITnsAD4uj9oKj1ABmbGlWBoETQcR6SDIVGiYm4no9fEqFQAYngbGg4KhIO2L0G8LGRmRzPF0EgwvGXl6Ap6AG1JBgsOJKABdVkqMq00X4iVSg4ymDnOUBRWjZWqjVa0RcvX41FWDC4x2MgBCuViQIAkty8PBwdBnrs3mN6YyURK2ZzubzINC%2BqHpXqJcyYYFIHNJdLgTAcJB4FZYKgFZaKNbNWm2TrkKm02bM7nZaaC0WS9AlRXkGqq9GVHa2PWJY7na7xYSSZ68qM888qTTUAGg%2BoyhSMBGSVHmTGudB5vzzfHEwLk0blsOJRmc0a89BW1526WrT2bQ39aptfE62KG9es4YN7vHebbFqW5Yqq%2Bfbimyg4OmmToutuBIerks57su6j3kwjbQGe7ybkyzIfrucYQgmGyMCGcJGpe4qUdRQq3gBqCGsBsqgR2XaQb2JFfrqv5pgxSY0cBbGHC2ZDUJx4GMC%2BvHVgO9qCcR4q3PSGKOM4yC4siIDAAQQA&format=glimdown

Why issue created? Because ember in-tempalte if already counting empty SafeString as false, but there is no official js way to check for empty safe string.

I think, we could workaround this case, extending SafeString class, adding length getter.

export class SafeString implements GlimmerSafeString {
  private __string: string;

  constructor(string: string) {
    this.__string = string;
  }

 /**
  getter to fix isEmpty case
*/
  get length() {
     return this.__string.length;
  }

  /**
    Get the string back to use as a string.

    @public
    @method toString
    @returns {String} The string marked as trusted
   */
  toString(): string {
    return `${this.__string}`;
  }

  /**
    Get the wrapped string as HTML to use without escaping.

    @public
    @method toHTML
    @returns {String} the trusted string, without any escaping applied
   */
  toHTML(): string {
    return this.toString();
  }
}

[kategengler]

I believe we are unlikely to touch isEmpty and other similar utilities; I'd generally prefer utilities from other generic libraries.

[lifeart]

@kategengler how about adding length to SafeString?

[kategengler]

That seems more likely.