prevent shutdown issues by making server thread daemonic

pytest_httpserver/httpserver.py

@@ -770,7 +770,8 @@ def start(self) -> None:
         )
 
         self.port = self.server.port  # Update port (needed if `port` was set to 0)
-        self.server_thread = threading.Thread(target=self.thread_target)
+        # Explicitly make the new thread daemonic to avoid shutdown issues
+        self.server_thread = threading.Thread(target=self.thread_target, daemon=True)
         self.server_thread.start()
 
     def stop(self):

tests/test_release.py

@@ -233,6 +233,7 @@ def test_sdist_contents(build: Build, version: str):
             "test_querystring.py",
             "test_release.py",
             "test_ssl.py",
+            "test_thread_type.py",
             "test_threaded.py",
             "test_urimatch.py",
             "test_wait.py",

tests/test_thread_type.py

@@ -0,0 +1,21 @@
+from __future__ import annotations
+
+import threading
+from typing import TYPE_CHECKING
+
+import requests
+from werkzeug import Response
+
+if TYPE_CHECKING:
+    from werkzeug import Request
+
+    from pytest_httpserver import HTTPServer
+
+
+def test_server_thread_is_daemon(httpserver: HTTPServer):
+    def handler(_request: Request):
+        return Response(f"{threading.current_thread().daemon}")
+
+    httpserver.expect_request("/foo").respond_with_handler(handler)
+
+    assert requests.get(httpserver.url_for("/foo")).text == "True"