From 28a3a97ad34499fc63754a7eb0b07c313e5b54b5 Mon Sep 17 00:00:00 2001
From: Hasan <hasanadeym@gmail.com>
Date: Fri, 6 Nov 2026 16:05:40 +0500
Subject: [PATCH] TCPServer.new takes a nil host and a String port

TCPServer.new([hostname,] port) passes both arguments to getaddrinfo,
so the host can be nil and the port can be a String, either a number
or a service name. The signature only allowed a String host and an
Integer port, so calls such as TCPServer.new(nil, 0) and
TCPServer.new("127.0.0.1", "8080") didn't type-check.

Allow String? for the host and Integer | String for the port, return
void from initialize, and add TCPServerSingletonTest#test_new.

Fixes #1671
---
 stdlib/socket/0/tcp_server.rbs       |  2 +-
 test/stdlib/socket/TCPServer_test.rb | 37 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 test/stdlib/socket/TCPServer_test.rb

diff --git a/stdlib/socket/0/tcp_server.rbs b/stdlib/socket/0/tcp_server.rbs
index 05f3d3f473..8dd6246d38 100644
--- a/stdlib/socket/0/tcp_server.rbs
+++ b/stdlib/socket/0/tcp_server.rbs
@@ -188,5 +188,5 @@ class TCPServer < TCPSocket
   # getaddrinfo() returns multiple addresses, TCPServer.new tries to create a
   # server socket for each address and returns first one that is successful.
   #
-  def initialize: (?String host, Integer port) -> untyped
+  def initialize: (?String? host, Integer | String port) -> void
 end
diff --git a/test/stdlib/socket/TCPServer_test.rb b/test/stdlib/socket/TCPServer_test.rb
new file mode 100644
index 0000000000..b871b0d201
--- /dev/null
+++ b/test/stdlib/socket/TCPServer_test.rb
@@ -0,0 +1,37 @@
+require_relative "../test_helper"
+
+require "socket"
+
+class TCPServerSingletonTest < Test::Unit::TestCase
+  include TestHelper
+
+  library "socket"
+  testing "singleton(::TCPServer)"
+
+  def test_new
+    assert_send_type(
+      "(::Integer) -> ::TCPServer",
+      TCPServer, :new, 0
+    ).close
+
+    assert_send_type(
+      "(::String) -> ::TCPServer",
+      TCPServer, :new, "0"
+    ).close
+
+    assert_send_type(
+      "(::String, ::Integer) -> ::TCPServer",
+      TCPServer, :new, "127.0.0.1", 0
+    ).close
+
+    assert_send_type(
+      "(::String, ::String) -> ::TCPServer",
+      TCPServer, :new, "127.0.0.1", "0"
+    ).close
+
+    assert_send_type(
+      "(nil, ::Integer) -> ::TCPServer",
+      TCPServer, :new, nil, 0
+    ).close
+  end
+end