创建任何对象的只读/不可变副本（包括深层属性） [英] Create a read-only/immutable copy of any object (including deep properties)

问题描述

如何在JavaScript中创建其属性无法更改的对象的只读/不可变版本？这也应适用于任何子对象的属性，等等。

How can I create a read-only/immutable version of an object in JavaScript, whose properties cannot be changed? This this should also apply to the properties of any sub objects and so on.

我遇到的所有方法都可以做到这一点（ Object.defineProperty ， Object.freeze 等）仅适用于对象的顶级属性，而不适用于子对象。

All methods I have come across to do this (Object.defineProperty, Object.freeze, etc) work only for the top level properties of the object, but not for the sub-objects.

（一个可能的用例：在创建/修改设置或配置在特定模块中键入对象，则需要以不可变的形式将其公开给程序的其余模块。）

(A possible use case: After creating/modifying a settings or configuration type object in a specific module, you need to expose it to the rest of the program's modules in an immutable form.)

推荐答案

这是我经过一番思考后想到的解决方案。可以很好地满足我的需求，所以我想分享一下QnA风格。
如果发现有任何改进/问题，请提出建议。

This is the solution I came up with after some thought. Works well for my needs so I thought I'd share it QnA style. Do suggest any improvements/issues if you you find them.

/**
 * Make the the specified object (deeply) immutable or "read-only", so that none of its
 * properties (or sub-properties) can be modified. The converted object is returned.
 * @param {object} obj Input object
 */
makeImmutable: function makeImmutable (obj) {
    if ((typeof obj === "object" && obj !== null) ||
        (Array.isArray? Array.isArray(obj): obj instanceof Array) ||
        (typeof obj === "function")) {

        Object.freeze(obj);

        for (var key in obj) {
            if (obj.hasOwnProperty(key)) {
                makeImmutable(obj[key]);
            }
        }
    }
    return obj;
}

编辑：
简化了代码。现在也可以正确处理数组。

Simplified the code. Also handles arrays correctly now.

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