fix tests

tests/abstract/test_abstract_blocks.py

@@ -348,6 +348,9 @@ class TestImagePIL(unittest.TestCase):
     @classmethod
     def _start_flask_server(cls):
         """Start a Flask server for URL testing."""
+        import urllib.request
+        import urllib.error
+
         cls.flask_app = Flask(__name__)
         cls.flask_port = 5555  # Use a specific port for testing
         cls.flask_server_running = True
@@ -356,6 +359,10 @@ class TestImagePIL(unittest.TestCase):
         def serve_test_image():
             return send_file(cls.jpg_path, mimetype='image/jpeg')
 
+        @cls.flask_app.route('/health')
+        def health_check():
+            return 'OK', 200
+
         def run_flask():
             cls.flask_app.run(host='127.0.0.1', port=cls.flask_port, debug=False,
                             use_reloader=False, threaded=True)
@@ -363,8 +370,20 @@ class TestImagePIL(unittest.TestCase):
         cls.flask_thread = threading.Thread(target=run_flask, daemon=True)
         cls.flask_thread.start()
 
-        # Wait for server to start
-        time.sleep(1)
+        # Wait for server to be ready with health check
+        max_wait = 5  # Maximum 5 seconds
+        wait_interval = 0.1  # Check every 100ms
+        elapsed = 0
+
+        while elapsed < max_wait:
+            try:
+                with urllib.request.urlopen(f'http://127.0.0.1:{cls.flask_port}/health', timeout=1) as response:
+                    if response.status == 200:
+                        break
+            except (urllib.error.URLError, ConnectionRefusedError, OSError):
+                pass
+            time.sleep(wait_interval)
+            elapsed += wait_interval
     
     def test_image_url_detection(self):
         """Test URL detection functionality."""