| #define-properties <sup>[![Version Badge][npm-version-svg]][package-url]</sup> |
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| [![Build Status][travis-svg]][travis-url] |
| [![dependency status][deps-svg]][deps-url] |
| [![dev dependency status][dev-deps-svg]][dev-deps-url] |
| [![License][license-image]][license-url] |
| [![Downloads][downloads-image]][downloads-url] |
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| [![npm badge][npm-badge-png]][package-url] |
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| [![browser support][testling-svg]][testling-url] |
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| Define multiple non-enumerable properties at once. Uses `Object.defineProperty` when available; falls back to standard assignment in older engines. |
| Existing properties are not overridden. Accepts a map of property names to a predicate that, when true, force-overrides. |
| |
| ## Example |
| |
| ```js |
| var define = require('define-properties'); |
| var assert = require('assert'); |
| |
| var obj = define({ a: 1, b: 2 }, { |
| a: 10, |
| b: 20, |
| c: 30 |
| }); |
| assert(obj.a === 1); |
| assert(obj.b === 2); |
| assert(obj.c === 30); |
| if (define.supportsDescriptors) { |
| assert.deepEqual(Object.keys(obj), ['a', 'b']); |
| assert.deepEqual(Object.getOwnPropertyDescriptor(obj, 'c'), { |
| configurable: true, |
| enumerable: false, |
| value: 30, |
| writable: false |
| }); |
| } |
| ``` |
| |
| Then, with predicates: |
| ```js |
| var define = require('define-properties'); |
| var assert = require('assert'); |
| |
| var obj = define({ a: 1, b: 2, c: 3 }, { |
| a: 10, |
| b: 20, |
| c: 30 |
| }, { |
| a: function () { return false; }, |
| b: function () { return true; } |
| }); |
| assert(obj.a === 1); |
| assert(obj.b === 20); |
| assert(obj.c === 3); |
| if (define.supportsDescriptors) { |
| assert.deepEqual(Object.keys(obj), ['a', 'c']); |
| assert.deepEqual(Object.getOwnPropertyDescriptor(obj, 'b'), { |
| configurable: true, |
| enumerable: false, |
| value: 20, |
| writable: false |
| }); |
| } |
| ``` |
| |
| ## Tests |
| Simply clone the repo, `npm install`, and run `npm test` |
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| [package-url]: https://npmjs.org/package/define-properties |
| [npm-version-svg]: http://versionbadg.es/ljharb/define-properties.svg |
| [travis-svg]: https://travis-ci.org/ljharb/define-properties.svg |
| [travis-url]: https://travis-ci.org/ljharb/define-properties |
| [deps-svg]: https://david-dm.org/ljharb/define-properties.svg |
| [deps-url]: https://david-dm.org/ljharb/define-properties |
| [dev-deps-svg]: https://david-dm.org/ljharb/define-properties/dev-status.svg |
| [dev-deps-url]: https://david-dm.org/ljharb/define-properties#info=devDependencies |
| [testling-svg]: https://ci.testling.com/ljharb/define-properties.png |
| [testling-url]: https://ci.testling.com/ljharb/define-properties |
| [npm-badge-png]: https://nodei.co/npm/define-properties.png?downloads=true&stars=true |
| [license-image]: http://img.shields.io/npm/l/define-properties.svg |
| [license-url]: LICENSE |
| [downloads-image]: http://img.shields.io/npm/dm/define-properties.svg |
| [downloads-url]: http://npm-stat.com/charts.html?package=define-properties |
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