node-fetch/README.md

node-fetch
==========

[![npm version][npm-image]][npm-url]
[![build status][travis-image]][travis-url]
[![coverage status][coveralls-image]][coveralls-url]

A light-weight module that brings `window.fetch` to node.js


# Motivation

I really like the notion of Matt Andrews' [isomorphic-fetch](https://github.com/matthew-andrews/isomorphic-fetch): it bridges the API gap between client-side and server-side http requests, so developers have less to worry about.

But I think the term [isomorphic](http://isomorphic.net/) is generally misleading: it gives developers a false sense of security that their javascript code will run happily on both controlled server environment as well as uncontrollable user browsers. When the latter is only true for a subset of modern browsers, not to mention quirks in native implementation.

Instead of implementing `XMLHttpRequest` in node to run browser-specific [fetch polyfill](https://github.com/github/fetch), why not go from node's `http` to `fetch` API directly? Node has native stream support, browserify build targets (browsers) don't, so underneath they are going to be vastly different anyway.

Hence `node-fetch`, minimal code for a `window.fetch` compatible API on node.js runtime.


# Features

- Stay consistent with `window.fetch` API.
- Make conscious trade-off when following [whatwg fetch spec](https://fetch.spec.whatwg.org/) and [stream spec](https://streams.spec.whatwg.org/) implementation details, document known difference.
- Use native promise, but allow substituting it with [insert your favorite promise library].


# Difference from client-side fetch

- See [Known limits](https://github.com/bitinn/node-fetch/blob/master/LIMITS.md) for details.
- If you happen to use a missing feature that `window.fetch` offers, feel free to open an issue.
- Pull requests are welcomed too!


# Install

`npm install node-fetch --save`


# Usage

```javascript
var fetch = require('node-fetch');

// plain text or html

fetch('https://github.com/')
	.then(function(res) {
		return res.text();
	}).then(function(body) {
		console.log(body);
	});

// json

fetch('https://api.github.com/users/github')
	.then(function(res) {
		return res.json();
	}).then(function(json) {
		console.log(json);
	});

// meta

fetch('https://github.com/')
	.then(function(res) {
		console.log(res.status);
		console.log(res.statusText);
		console.log(res.headers.raw());
		console.log(res.headers.get('content-type'));
	});

// post

fetch('http://httpbin.org/post', { method: 'POST', body: 'a=1' })
	.then(function(res) {
		return res.json();
	}).then(function(json) {
		console.log(json);
	});

// post with stream from resumer

var resumer = require('resumer');
var stream = resumer().queue('a=1').end();
fetch('http://httpbin.org/post', { method: 'POST', body: stream })
	.then(function(res) {
		return res.json();
	}).then(function(json) {
		console.log(json);
	});

// post with form-data

var FormData = require('form-data');
var form = new FormData();
form.append('a', 1);
fetch('http://httpbin.org/post', { method: 'POST', body: form, headers: form.getHeaders() })
	.then(function(res) {
		return res.json();
	}).then(function(json) {
		console.log(json);
	});

// node 0.11+, yield with co

var co = require('co');
co(function *() {
	var res = yield fetch('https://api.github.com/users/github')
		.then(function(res) {
			return res.json();
		});

	console.log(res);
});
```

See [test cases](https://github.com/bitinn/node-fetch/blob/master/test/test.js) for more examples.


# License

MIT


# Acknowledgement

Thanks to [github/fetch](https://github.com/github/fetch) for providing a solid implementation reference.


[npm-image]: https://img.shields.io/npm/v/node-fetch.svg?style=flat-square
[npm-url]: https://www.npmjs.com/package/node-fetch
[travis-image]: https://img.shields.io/travis/bitinn/node-fetch.svg?style=flat-square
[travis-url]: https://travis-ci.org/bitinn/node-fetch
[coveralls-image]: https://img.shields.io/coveralls/bitinn/node-fetch.svg?style=flat-square
[coveralls-url]: https://coveralls.io/r/bitinn/node-fetch