webapp loop

main.py

@@ -121,6 +121,7 @@ def main() -> int:
     #
     # watcher.start()
     # watcher.wait()   # blocks until stop() is called via a signal
+    web_app.wait()     # keep process alive while the watcher is disabled
     return 0
 
 

src/MatchesWebApp.py

@@ -265,6 +265,7 @@ class MatchesWebApp:
         self._port = port
         self._build_lock = threading.Lock()
         self._app = Flask(__name__)
+        self._thread: "threading.Thread | None" = None
         self._register_routes()
 
     @property
@@ -272,19 +273,32 @@ class MatchesWebApp:
         return self._app
 
     def start(self) -> threading.Thread:
-        """Starts the Flask server on a daemon thread and returns it."""
-        thread = threading.Thread(
+        """
+        Starts the Flask server on a background thread and returns it.
+
+        The thread is non-daemon so the process stays alive even when the
+        caller does not explicitly join() — important when this is the
+        only foreground task (e.g. watcher disabled for testing).
+        """
+        if self._thread is not None and self._thread.is_alive():
+            return self._thread
+        self._thread = threading.Thread(
             target=self._app.run,
             kwargs={"host": self._host, "port": self._port,
                     "debug": False, "use_reloader": False,
                     "threaded": True},
             name="MatchesWebApp",
-            daemon=True,
+            daemon=False,
         )
-        thread.start()
+        self._thread.start()
         print(f"[MatchesWebApp] listening on {self._host}:{self._port}",
               flush=True)
-        return thread
+        return self._thread
+
+    def wait(self) -> None:
+        """Blocks until the Flask thread exits (or returns immediately if not started)."""
+        if self._thread is not None:
+            self._thread.join()
 
     # ------------------------------------------------------------------
     # Routes