21 lines
423 B
JavaScript
21 lines
423 B
JavaScript
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'use strict';
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const net = require('net');
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const getPort = port => new Promise((resolve, reject) => {
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const server = net.createServer();
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server.unref();
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server.on('error', reject);
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server.listen(port, () => {
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const port = server.address().port;
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server.close(() => {
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resolve(port);
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});
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});
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});
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module.exports = preferredPort => preferredPort ?
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getPort(preferredPort).catch(() => getPort(0)) :
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getPort(0);
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