http/util.js

1// Licensed to the Software Freedom Conservancy (SFC) under one
2// or more contributor license agreements. See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership. The SFC licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License. You may obtain a copy of the License at
8//
9// http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied. See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18/**
19 * @fileoverview Various HTTP utilities.
20 */
21
22var base = require('../_base'),
23 HttpClient = require('./index').HttpClient,
24 checkResponse = base.require('bot.response').checkResponse,
25 Executor = base.require('webdriver.http.Executor'),
26 HttpRequest = base.require('webdriver.http.Request'),
27 Command = base.require('webdriver.Command'),
28 CommandName = base.require('webdriver.CommandName'),
29 promise = base.require('webdriver.promise');
30
31
32
33/**
34 * Queries a WebDriver server for its current status.
35 * @param {string} url Base URL of the server to query.
36 * @param {function(Error, *=)} callback The function to call with the
37 * response.
38 */
39function getStatus(url, callback) {
40 var client = new HttpClient(url);
41 var executor = new Executor(client);
42 var command = new Command(CommandName.GET_SERVER_STATUS);
43 executor.execute(command, function(err, responseObj) {
44 if (err) return callback(err);
45 try {
46 checkResponse(responseObj);
47 } catch (ex) {
48 return callback(ex);
49 }
50 callback(null, responseObj['value']);
51 });
52}
53
54
55// PUBLIC API
56
57
58/**
59 * Queries a WebDriver server for its current status.
60 * @param {string} url Base URL of the server to query.
61 * @return {!webdriver.promise.Promise.<!Object>} A promise that resolves with
62 * a hash of the server status.
63 */
64exports.getStatus = function(url) {
65 return promise.checkedNodeCall(getStatus.bind(null, url));
66};
67
68
69/**
70 * Waits for a WebDriver server to be healthy and accepting requests.
71 * @param {string} url Base URL of the server to query.
72 * @param {number} timeout How long to wait for the server.
73 * @return {!webdriver.promise.Promise} A promise that will resolve when the
74 * server is ready.
75 */
76exports.waitForServer = function(url, timeout) {
77 var ready = promise.defer(),
78 start = Date.now(),
79 checkServerStatus = getStatus.bind(null, url, onResponse);
80 checkServerStatus();
81 return ready.promise;
82
83 function onResponse(err) {
84 if (!ready.isPending()) return;
85 if (!err) return ready.fulfill();
86
87 if (Date.now() - start > timeout) {
88 ready.reject(
89 Error('Timed out waiting for the WebDriver server at ' + url));
90 } else {
91 setTimeout(function() {
92 if (ready.isPending()) {
93 checkServerStatus();
94 }
95 }, 50);
96 }
97 }
98};
99
100
101/**
102 * Polls a URL with GET requests until it returns a 2xx response or the
103 * timeout expires.
104 * @param {string} url The URL to poll.
105 * @param {number} timeout How long to wait, in milliseconds.
106 * @return {!webdriver.promise.Promise} A promise that will resolve when the
107 * URL responds with 2xx.
108 */
109exports.waitForUrl = function(url, timeout) {
110 var client = new HttpClient(url),
111 request = new HttpRequest('GET', ''),
112 testUrl = client.send.bind(client, request, onResponse),
113 ready = promise.defer(),
114 start = Date.now();
115 testUrl();
116 return ready.promise;
117
118 function onResponse(err, response) {
119 if (!ready.isPending()) return;
120 if (!err && response.status > 199 && response.status < 300) {
121 return ready.fulfill();
122 }
123
124 if (Date.now() - start > timeout) {
125 ready.reject(Error(
126 'Timed out waiting for the URL to return 2xx: ' + url));
127 } else {
128 setTimeout(function() {
129 if (ready.isPending()) {
130 testUrl();
131 }
132 }, 50);
133 }
134 }
135};