<pre class="shiki github-dark shaku"><code>function completeAssign(target, ...sources) { // 1. 目标是 null 或 undefined 时，必须抛出 TypeError if (target === null || target === undefined) { throw new TypeError('Cannot convert undefined or null to object'); } // 2. 将原始值目标装箱 const to = Object(target); for (const source of sources) { // 3. 跳过 null / undefined 的源对象 if (source === null || source === undefined) continue; const fromObject = Object(source) // 4. 获取源对象所有“自有”属性键（字符串 + Symbol） const keys = [ ...Object.getOwnPropertyNames(fromObject), ...Object.getOwnPropertySymbols(fromObject), ]; for (const key of keys) { // 5. “不可枚举”的属性也要处理 const descriptor = Object.getOwnPropertyDescriptor(fromObject, key); // if (!descriptor || !descriptor.enumerable) continue; if (!descriptor) continue; // 6. 关键：完整复制描述符，而不是只复制值 Object.defineProperty(to, key, descriptor); } } return to;}</code></pre>

27. implement completeAssign()

This is a follow-up on 26. implement Object.assign(). Object.assign() assigns the enumerable properties, so getters are not copied, non-enumerable pro…