parro-it/private-class

# private-class

> A module to protect private properties of classes

This module allow to protect private properties of classes.

It works by creating a new prototype that wraps each methods of the original one.

On creation of a new instance of the wrapped prototype, a new instance of the original class is created and saved in a WeakMap.

Wrapped methods retrieve the original class instance from there and forward the call to its method.

## Usage

```js
const priv = require('private-class');

const Person = priv(class Person {
    constructor(name, age) {
        this._name = name;
        this._age = age;
    }

    get age() {
        return this._age;
    }

    set age(value) {
        this._age = value;
    }

    name() {
        return this._name;
    }
});

const p = new Person('Andrea', 40);
// public function are visible
console.log(typeof p.name);
// <-- function

// public getter & setter are visible
p.age = 41;
console.log(p.age);
// <-- 41

// public function can read private fields
console.log(p.name());
// <-- Andrea

// extern code can not read private fields
console.log(p._name);
// <-- undefined
console.log(p._age);
// <-- undefined
```

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## API

```js
const privateClass = (Class: function): function
```

Given a class, return a new class that doesn't allow to access private properties.

## Install

With [npm](https://npmjs.org/) installed, run

```
$ npm install private-class
```

## See Also

- [`noffle/common-readme`](https://github.com/noffle/common-readme)

## License

MIT