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/*! | |
* merge-descriptors | |
* Copyright(c) 2014 Jonathan Ong | |
* Copyright(c) 2015 Douglas Christopher Wilson | |
* MIT Licensed | |
*/ | |
/** | |
* Module exports. | |
* @public | |
*/ | |
module.exports = merge | |
/** | |
* Module variables. | |
* @private | |
*/ | |
var hasOwnProperty = Object.prototype.hasOwnProperty | |
/** | |
* Merge the property descriptors of `src` into `dest` | |
* | |
* @param {object} dest Object to add descriptors to | |
* @param {object} src Object to clone descriptors from | |
* @param {boolean} [redefine=true] Redefine `dest` properties with `src` properties | |
* @returns {object} Reference to dest | |
* @public | |
*/ | |
function merge(dest, src, redefine) { | |
if (!dest) { | |
throw new TypeError('argument dest is required') | |
} | |
if (!src) { | |
throw new TypeError('argument src is required') | |
} | |
if (redefine === undefined) { | |
// Default to true | |
redefine = true | |
} | |
Object.getOwnPropertyNames(src).forEach(function forEachOwnPropertyName(name) { | |
if (!redefine && hasOwnProperty.call(dest, name)) { | |
// Skip desriptor | |
return | |
} | |
// Copy descriptor | |
var descriptor = Object.getOwnPropertyDescriptor(src, name) | |
Object.defineProperty(dest, name, descriptor) | |
}) | |
return dest | |
} | |