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 |
|
20 | const net = require('net')
|
21 |
|
22 | /**
|
23 | * Tests if a port is free.
|
24 | * @param {number} port The port to test.
|
25 | * @param {string=} opt_host The bound host to test the {@code port} against.
|
26 | * Defaults to {@code INADDR_ANY}.
|
27 | * @return {!Promise<boolean>} A promise that will resolve with whether the port
|
28 | * is free.
|
29 | */
|
30 | function isFree(port, opt_host) {
|
31 | return new Promise((resolve, reject) => {
|
32 | let server = net.createServer().on('error', function (e) {
|
33 | if (e.code === 'EADDRINUSE' || e.code === 'EACCES') {
|
34 | resolve(false)
|
35 | } else {
|
36 | reject(e)
|
37 | }
|
38 | })
|
39 |
|
40 | server.listen(port, opt_host, function () {
|
41 | server.close(() => resolve(true))
|
42 | })
|
43 | })
|
44 | }
|
45 |
|
46 | /**
|
47 | * @param {string=} opt_host The bound host to test the {@code port} against.
|
48 | * Defaults to {@code INADDR_ANY}.
|
49 | * @return {!Promise<number>} A promise that will resolve to a free port. If a
|
50 | * port cannot be found, the promise will be rejected.
|
51 | */
|
52 |
|
53 | function findFreePort(opt_host) {
|
54 | return new Promise((resolve, reject) => {
|
55 | const server = net.createServer()
|
56 | server.on('listening', function () {
|
57 | resolve(server.address().port)
|
58 | server.close()
|
59 | })
|
60 | server.on('error', (e) => {
|
61 | if (e.code === 'EADDRINUSE' || e.code === 'EACCES') {
|
62 | resolve('Unable to find a free port')
|
63 | } else {
|
64 | reject(e)
|
65 | }
|
66 | })
|
67 | // By providing 0 we let the operative system find an arbitrary port
|
68 | server.listen(0, opt_host)
|
69 | })
|
70 | }
|
71 |
|
72 | // PUBLIC API
|
73 |
|
74 | exports.findFreePort = findFreePort
|
75 | exports.isFree = isFree
|