Merge pull request WP-API#432 from WP-API/implement-fetch-transport

Implement fetch transport

Author: kadamwhite

Diff for: bin/jekyll

@@ -0,0 +1,37 @@
+/**
+ * This script will start the Jekyll server in the context of the docs
+ * directory. It is only for use in local development, and sets the --baseurl
+ * option to override the production-only baseurl in _config.yml.
+ */
+/* eslint-disable no-console */
+'use strict';
+
+const path = require( 'path' );
+const spawn = require( 'child_process' ).spawn;
+const argv = require( 'minimist' )( process.argv.slice( 2 ) );
+
+// Execute within the context of the docs directory
+const docsDir = path.resolve( __dirname, '../documentation' );
+
+if ( argv.install || argv.i ) {
+	// Install the ruby bundle needed to run jekyll
+	const server = spawn( 'bundle', [ 'install' ], {
+		cwd: docsDir,
+		stdio: 'inherit',
+	} );
+
+	server.on( 'error', err => console.error( err ) );
+} else {
+	// Start the server in local dev mode
+	const bundleOptions = [ 'exec', 'jekyll', 'serve', '--baseurl', '' ];
+	if ( argv.host ) {
+		bundleOptions.push( '--host', argv.host );
+	}
+
+	const server = spawn( 'bundle', bundleOptions, {
+		cwd: docsDir,
+		stdio: 'inherit',
+	} );
+
+	server.on( 'error', err => console.error( err ) );
+}

Diff for: bin/jekyll.js

@@ -0,0 +1,14 @@
+# `wpapi/fetch`
+
+This endpoint returns a version of the WPAPI library configured to use Fetch for HTTP requests.
+
+## Installation & Usage
+
+Install both `wpapi` and `isomorphic-unfetch` using the command `npm install --save wpapi isomorphic-unfetch`.
+
+```js
+import WPAPI from 'wpapi/fetch';
+
+// Configure and use WPAPI as normal
+const site = new WPAPI( { /* ... */ } );
+```

Diff for: fetch/README.md

@@ -0,0 +1,271 @@
+/**
+ * @module fetch-transport
+ */
+'use strict';
+
+const fetch = require( 'node-fetch' );
+const FormData = require( 'form-data' );
+const fs = require( 'fs' );
+
+const objectReduce = require( '../lib/util/object-reduce' );
+const { createPaginationObject } = require( '../lib/pagination' );
+
+/**
+ * Utility method to set a header value on a fetch configuration object.
+ *
+ * @method _setHeader
+ * @private
+ * @param {Object} config A configuration object of unknown completeness
+ * @param {string} header String name of the header to set
+ * @param {string} value  Value of the header to set
+ * @returns {Object} The modified configuration object
+ */
+const _setHeader = ( config, header, value ) => ( {
+	...config,
+	headers: {
+		...( config && config.headers ? config.headers : null ),
+		[ header ]: value,
+	},
+} );
+
+/**
+ * Set any provided headers on the outgoing request object. Runs after _auth.
+ *
+ * @method _setHeaders
+ * @private
+ * @param {Object} config A fetch request configuration object
+ * @param {Object} options A WPRequest _options object
+ * @param {Object} A fetch config object, with any available headers set
+ */
+function _setHeaders( config, options ) {
+	// If there's no headers, do nothing
+	if ( ! options.headers ) {
+		return config;
+	}
+
+	return objectReduce(
+		options.headers,
+		( config, value, key ) => _setHeader( config, key, value ),
+		config,
+	);
+}
+
+/**
+ * Conditionally set basic or nonce authentication on a server request object.
+ *
+ * @method _auth
+ * @private
+ * @param {Object} config A fetch request configuration object
+ * @param {Object} options A WPRequest _options object
+ * @param {Boolean} forceAuthentication whether to force authentication on the request
+ * @param {Object} A fetch request object, conditionally configured to use basic auth
+ */
+function _auth( config, options, forceAuthentication ) {
+	// If we're not supposed to authenticate, don't even start
+	if ( ! forceAuthentication && ! options.auth && ! options.nonce ) {
+		return config;
+	}
+
+	// Enable nonce in options for Cookie authentication http://wp-api.org/guides/authentication.html
+	if ( options.nonce ) {
+		config.credentials = 'same-origin';
+		return _setHeader( config, 'X-WP-Nonce', options.nonce );
+	}
+
+	// If no username or no password, can't authenticate
+	if ( ! options.username || ! options.password ) {
+		return config;
+	}
+
+	// Can authenticate: set basic auth parameters on the config
+	let authorization = `${ options.username }:${ options.password }`;
+	if ( global.Buffer ) {
+		authorization = global.Buffer.from( authorization ).toString( 'base64' );
+	} else if ( global.btoa ) {
+		authorization = global.btoa( authorization );
+	}
+
+	return _setHeader( config, 'Authorization', `Basic ${ authorization }` );
+}
+
+// HTTP-Related Helpers
+// ====================
+
+/**
+ * Get the response headers as a regular JavaScript object.
+ *
+ * @param {Object} response Fetch response object.
+ */
+function getHeaders( response ) {
+	const headers = {};
+	response.headers.forEach( ( value, key ) => {
+		headers[ key ] = value;
+	} );
+	return headers;
+}
+
+/**
+ * Return the body of the request, augmented with pagination information if the
+ * result is a paged collection.
+ *
+ * @private
+ * @param {WPRequest} wpreq The WPRequest representing the returned HTTP response
+ * @param {Object} response The fetch response object for the HTTP call
+ * @returns {Object} The JSON data of the response, conditionally augmented with
+ *                   pagination information if the response is a partial collection.
+ */
+const parseFetchResponse = ( response, wpreq ) => {
+	// Check if an HTTP error occurred.
+	if ( ! response.ok ) {
+		// Extract and return the API-provided error object if the response is
+		// not ok, i.e. if the error was from the API and not internal to fetch.
+		return response.json().then( ( err ) => {
+			// Throw the error object to permit proper error handling.
+			throw err;
+		}, () => {
+			// JSON serialization failed; throw the underlying response.
+			throw response;
+		} );
+	}
+
+	// If the response is OK, process & return the JSON data.
+	return response.json().then( ( body ) => {
+		// Construct a response the pagination helper can understand.
+		const mockResponse = {
+			headers: getHeaders( response ),
+		};
+
+		const _paging = createPaginationObject( mockResponse, wpreq._options, wpreq.transport );
+		if ( _paging ) {
+			body._paging = _paging;
+		}
+		return body;
+	} );
+};
+
+// HTTP Methods: Private HTTP-verb versions
+// ========================================
+
+const send = ( wpreq, config ) => fetch(
+	wpreq.toString(),
+	_setHeaders( _auth( config, wpreq._options ), wpreq._options )
+).then( ( response ) => {
+	// return response.headers.get( 'Link' );
+	return parseFetchResponse( response, wpreq );
+} );
+
+/**
+ * @method get
+ * @async
+ * @param {WPRequest} wpreq A WPRequest query object
+ * @returns {Promise} A promise to the results of the HTTP request
+ */
+function _httpGet( wpreq ) {
+	return send( wpreq, {
+		method: 'GET',
+	} );
+}
+
+/**
+ * Invoke an HTTP "POST" request against the provided endpoint
+ * @method post
+ * @async
+ * @param {WPRequest} wpreq A WPRequest query object
+ * @param {Object} data The data for the POST request
+ * @returns {Promise} A promise to the results of the HTTP request
+ */
+function _httpPost( wpreq, data = {} ) {
+	let file = wpreq._attachment;
+	if ( file ) {
+		// Handle files provided as a path string
+		if ( typeof file === 'string' ) {
+			file = fs.createReadStream( file );
+		}
+
+		// Build the form data object
+		const form = new FormData();
+		form.append( 'file', file, wpreq._attachmentName );
+		Object.keys( data ).forEach( key => form.append( key, data[ key ] ) );
+
+		// Fire off the media upload request
+		return send( wpreq, {
+			method: 'POST',
+			redirect: 'follow',
+			body: form,
+		} );
+	}
+
+	return send( wpreq, {
+		method: 'POST',
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		redirect: 'follow',
+		body: JSON.stringify( data ),
+	} );
+}
+
+/**
+ * @method put
+ * @async
+ * @param {WPRequest} wpreq A WPRequest query object
+ * @param {Object} data The data for the PUT request
+ * @returns {Promise} A promise to the results of the HTTP request
+ */
+function _httpPut( wpreq, data = {} ) {
+	return send( wpreq, {
+		method: 'PUT',
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		redirect: 'follow',
+		body: JSON.stringify( data ),
+	} );
+}
+
+/**
+ * @method delete
+ * @async
+ * @param {WPRequest} wpreq A WPRequest query object
+ * @param {Object} [data] Data to send along with the DELETE request
+ * @returns {Promise} A promise to the results of the HTTP request
+ */
+function _httpDelete( wpreq, data ) {
+	const config = {
+		method: 'DELETE',
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		redirect: 'follow',
+	};
+
+	if ( data ) {
+		config.body = JSON.stringify( data );
+	}
+
+	return send( wpreq, config );
+}
+
+/**
+ * @method head
+ * @async
+ * @param {WPRequest} wpreq A WPRequest query object
+ * @returns {Promise} A promise to the header results of the HTTP request
+ */
+function _httpHead( wpreq ) {
+	const url = wpreq.toString();
+	const config = _setHeaders( _auth( {
+		method: 'HEAD',
+	}, wpreq._options, true ), wpreq._options );
+
+	return fetch( url, config )
+		.then( response => getHeaders( response ) );
+}
+
+module.exports = {
+	delete: _httpDelete,
+	get: _httpGet,
+	head: _httpHead,
+	post: _httpPost,
+	put: _httpPut,
+};

Diff for: fetch/fetch-transport.js

@@ -0,0 +1,6 @@
+const WPAPI = require( '../wpapi' );
+const fetchTransport = require( './fetch-transport' );
+const bindTransport = require( '../lib/bind-transport' );
+
+// Bind the fetch-based HTTP transport to the WPAPI constructor
+module.exports = bindTransport( WPAPI, fetchTransport );

Diff for: fetch/index.js

@@ -0,0 +1,5 @@
+module.exports = {
+	'env': {
+		jest: true,
+	},
+};