136 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
#object.assign <sup>[![Version Badge][npm-version-svg]][npm-url]</sup>
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[![Build Status][travis-svg]][travis-url]
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[![dependency status][deps-svg]][deps-url]
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[![dev dependency status][dev-deps-svg]][dev-deps-url]
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[![License][license-image]][license-url]
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[![Downloads][downloads-image]][downloads-url]
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[![npm badge][npm-badge-png]][npm-url]
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[![browser support][testling-png]][testling-url]
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An Object.assign shim. Invoke its "shim" method to shim Object.assign if it is unavailable.
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This package implements the [es-shim API](https://github.com/es-shims/api) interface. It works in an ES3-supported environment and complies with the [spec](http://www.ecma-international.org/ecma-262/6.0/#sec-object.assign). In an ES6 environment, it will also work properly with `Symbol`s.
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Takes a minimum of 2 arguments: `target` and `source`.
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Takes a variable sized list of source arguments - at least 1, as many as you want.
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Throws a TypeError if the `target` argument is `null` or `undefined`.
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Most common usage:
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```js
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var assign = require('object.assign').getPolyfill(); // returns native method if compliant
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	/* or */
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var assign = require('object.assign/polyfill')(); // returns native method if compliant
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```
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## Example
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```js
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var assert = require('assert');
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// Multiple sources!
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var target = { a: true };
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var source1 = { b: true };
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var source2 = { c: true };
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var sourceN = { n: true };
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var expected = {
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	a: true,
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	b: true,
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	c: true,
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	n: true
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};
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assign(target, source1, source2, sourceN);
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assert.deepEqual(target, expected); // AWESOME!
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```
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```js
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var target = {
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	a: true,
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	b: true,
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	c: true
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};
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var source1 = {
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	c: false,
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	d: false
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};
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var sourceN = {
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	e: false
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};
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var assigned = assign(target, source1, sourceN);
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assert.equal(target, assigned); // returns the target object
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assert.deepEqual(assigned, {
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	a: true,
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	b: true,
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	c: false,
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	d: false,
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	e: false
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});
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```
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```js
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/* when Object.assign is not present */
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delete Object.assign;
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var shimmedAssign = require('object.assign').shim();
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	/* or */
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var shimmedAssign = require('object.assign/shim')();
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assert.equal(shimmedAssign, assign);
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var target = {
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	a: true,
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	b: true,
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	c: true
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};
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var source = {
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	c: false,
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	d: false,
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	e: false
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};
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var assigned = assign(target, source);
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assert.deepEqual(Object.assign(target, source), assign(target, source));
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```
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```js
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/* when Object.assign is present */
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var shimmedAssign = require('object.assign').shim();
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assert.equal(shimmedAssign, Object.assign);
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var target = {
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	a: true,
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	b: true,
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	c: true
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};
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var source = {
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	c: false,
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	d: false,
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	e: false
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};
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assert.deepEqual(Object.assign(target, source), assign(target, source));
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```
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## Tests
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Simply clone the repo, `npm install`, and run `npm test`
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[npm-url]: https://npmjs.org/package/object.assign
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[npm-version-svg]: http://versionbadg.es/ljharb/object.assign.svg
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[travis-svg]: https://travis-ci.org/ljharb/object.assign.svg
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[travis-url]: https://travis-ci.org/ljharb/object.assign
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[deps-svg]: https://david-dm.org/ljharb/object.assign.svg?theme=shields.io
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[deps-url]: https://david-dm.org/ljharb/object.assign
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[dev-deps-svg]: https://david-dm.org/ljharb/object.assign/dev-status.svg?theme=shields.io
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[dev-deps-url]: https://david-dm.org/ljharb/object.assign#info=devDependencies
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[testling-png]: https://ci.testling.com/ljharb/object.assign.png
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[testling-url]: https://ci.testling.com/ljharb/object.assign
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[npm-badge-png]: https://nodei.co/npm/object.assign.png?downloads=true&stars=true
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[license-image]: http://img.shields.io/npm/l/object.assign.svg
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[license-url]: LICENSE
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[downloads-image]: http://img.shields.io/npm/dm/object.assign.svg
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[downloads-url]: http://npm-stat.com/charts.html?package=object.assign
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