http/util.js

1// Copyright 2013 Selenium committers
2// Copyright 2013 Software Freedom Conservancy
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8// http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16/**
17 * @fileoverview Various HTTP utilities.
18 */
19
20var base = require('../_base'),
21 HttpClient = require('./index').HttpClient,
22 checkResponse = base.require('bot.response').checkResponse,
23 Executor = base.require('webdriver.http.Executor'),
24 HttpRequest = base.require('webdriver.http.Request'),
25 Command = base.require('webdriver.Command'),
26 CommandName = base.require('webdriver.CommandName'),
27 promise = base.require('webdriver.promise');
28
29
30
31/**
32 * Queries a WebDriver server for its current status.
33 * @param {string} url Base URL of the server to query.
34 * @param {function(Error, *=)} callback The function to call with the
35 * response.
36 */
37function getStatus(url, callback) {
38 var client = new HttpClient(url);
39 var executor = new Executor(client);
40 var command = new Command(CommandName.GET_SERVER_STATUS);
41 executor.execute(command, function(err, responseObj) {
42 if (err) return callback(err);
43 try {
44 checkResponse(responseObj);
45 } catch (ex) {
46 return callback(ex);
47 }
48 callback(null, responseObj['value']);
49 });
50}
51
52
53// PUBLIC API
54
55
56/**
57 * Queries a WebDriver server for its current status.
58 * @param {string} url Base URL of the server to query.
59 * @return {!webdriver.promise.Promise.<!Object>} A promise that resolves with
60 * a hash of the server status.
61 */
62exports.getStatus = function(url) {
63 return promise.checkedNodeCall(getStatus.bind(null, url));
64};
65
66
67/**
68 * Waits for a WebDriver server to be healthy and accepting requests.
69 * @param {string} url Base URL of the server to query.
70 * @param {number} timeout How long to wait for the server.
71 * @return {!webdriver.promise.Promise} A promise that will resolve when the
72 * server is ready.
73 */
74exports.waitForServer = function(url, timeout) {
75 var ready = promise.defer(),
76 start = Date.now(),
77 checkServerStatus = getStatus.bind(null, url, onResponse);
78 checkServerStatus();
79 return ready.promise;
80
81 function onResponse(err) {
82 if (!ready.isPending()) return;
83 if (!err) return ready.fulfill();
84
85 if (Date.now() - start > timeout) {
86 ready.reject(
87 Error('Timed out waiting for the WebDriver server at ' + url));
88 } else {
89 setTimeout(function() {
90 if (ready.isPending()) {
91 checkServerStatus();
92 }
93 }, 50);
94 }
95 }
96};
97
98
99/**
100 * Polls a URL with GET requests until it returns a 2xx response or the
101 * timeout expires.
102 * @param {string} url The URL to poll.
103 * @param {number} timeout How long to wait, in milliseconds.
104 * @return {!webdriver.promise.Promise} A promise that will resolve when the
105 * URL responds with 2xx.
106 */
107exports.waitForUrl = function(url, timeout) {
108 var client = new HttpClient(url),
109 request = new HttpRequest('GET', ''),
110 testUrl = client.send.bind(client, request, onResponse),
111 ready = promise.defer(),
112 start = Date.now();
113 testUrl();
114 return ready.promise;
115
116 function onResponse(err, response) {
117 if (!ready.isPending()) return;
118 if (!err && response.status > 199 && response.status < 300) {
119 return ready.fulfill();
120 }
121
122 if (Date.now() - start > timeout) {
123 ready.reject(Error(
124 'Timed out waiting for the URL to return 2xx: ' + url));
125 } else {
126 setTimeout(function() {
127 if (ready.isPending()) {
128 testUrl();
129 }
130 }, 50);
131 }
132 }
133};