test: deflake test-net-autoselectfamily-local-port

test/sequential/test-net-autoselectfamily-local-port.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasIPv6) common.skip('IPv6 loopback is unavailable');
+
+const assert = require('node:assert');
+const { createConnection, createServer } = require('node:net');
+const { TCP } = process.binding('tcp_wrap');
+// A pending IPv6 connect with a fixed source port must be closed before an
+// IPv4 candidate binds to that port.
+TCP.prototype.connect6 = function() {
+  return 0;
+};
+
+const server = createServer(common.mustCall((socket) => socket.end()));
+server.listen(0, '127.0.0.1', common.mustCall(() => {
+  const port = server.address().port;
+  const connection = createConnection({
+    host: 'example.org',
+    port,
+    localPort: common.PORT,
+    lookup: common.mustCall((host, options, callback) => {
+      process.nextTick(callback, null, [
+        { address: '::1', family: 6 },
+        { address: '127.0.0.1', family: 4 },
+      ]);
+    }),
+    autoSelectFamily: true,
+    autoSelectFamilyAttemptTimeout: 10,
+  });
+  connection.on('connect', common.mustCall(() => {
+    assert.strictEqual(connection.localPort, common.PORT);
+    assert.strictEqual(connection.remoteAddress, '127.0.0.1');
+  }));
+  connection.on('error', common.mustNotCall());
+  connection.on('close', common.mustCall(() => server.close()));
+}));