False arguments serialized as strings

Suppose use-case for conditional applying classes:

import { render } from "preact";
import { html } from "htm/preact";

let el = document.createElement("div");
render(
  html`
    <div class="${false} ${null} ${undefined} ${"foo"}" />
  `,
  el
);

console.log(el.innerHTML);
// <div class="false null undefined foo"></div> 

Sandbox

That's unexpected that the htm serializes false/null class values literally.
That can be worked around with clsx or alike, but.

從提供的 CodeSandbox 重現開始，追蹤 htm/preact 對插值 class 值的屬性序列化路徑。確認 false、null、undefined 和 "foo" 的預期處理方式，然後驗證該重現不再輸出不需要的字面值。