tls: allow client-side sockets to be half-opened

Make `tls.connect()` support an `allowHalfOpen` option which specifies
whether or not to allow the connection to be half-opened when the
`socket` option is not specified.

PR-URL: https://github.com/nodejs/node/pull/27836
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ouyang Yadong <oyydoibh@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/test/parallel/test-tls-socket-allow-half-open-option.js b/test/parallel/test-tls-socket-allow-half-open-option.js
new file mode 100644
index 0000000000..36449a6130
--- /dev/null
+++ b/test/parallel/test-tls-socket-allow-half-open-option.js
@@ -0,0 +1,38 @@
+'use strict';
+
+const common = require('../common');
+
+// Test the `allowHalfOpen` option of the `tls.TLSSocket` constructor.
+
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const assert = require('assert');
+const net = require('net');
+const stream = require('stream');
+const tls = require('tls');
+
+{
+  // The option is ignored when the `socket` argument is a `net.Socket`.
+  const socket = new tls.TLSSocket(new net.Socket(), { allowHalfOpen: true });
+  assert.strictEqual(socket.allowHalfOpen, false);
+}
+
+{
+  // The option is ignored when the `socket` argument is a generic
+  // `stream.Duplex`.
+  const duplex = new stream.Duplex({ allowHalfOpen: false });
+  const socket = new tls.TLSSocket(duplex, { allowHalfOpen: true });
+  assert.strictEqual(socket.allowHalfOpen, false);
+}
+
+{
+  const socket = new tls.TLSSocket();
+  assert.strictEqual(socket.allowHalfOpen, false);
+}
+
+{
+  // The option is honored when the `socket` argument is not specified.
+  const socket = new tls.TLSSocket(undefined, { allowHalfOpen: true });
+  assert.strictEqual(socket.allowHalfOpen, true);
+}