define-properties (original) (raw)

1.2.1 • Public • Published 2 years ago

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define-properties

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

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:

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