Fix FastAPIWebsocketTransport to handle both binary and text messages

tests/test_fastapi_websocket.py

@@ -0,0 +1,70 @@
+#
+# Copyright (c) 2024-2026, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+import unittest
+from unittest.mock import AsyncMock
+
+from pipecat.transports.websocket.fastapi import _WebSocketMessageIterator
+
+
+class TestWebSocketMessageIterator(unittest.IsolatedAsyncioTestCase):
+    async def test_yields_binary_message(self):
+        mock_websocket = AsyncMock()
+        mock_websocket.receive.side_effect = [
+            {"type": "websocket.receive", "bytes": b"binary data", "text": None},
+            {"type": "websocket.disconnect"},
+        ]
+
+        iterator = _WebSocketMessageIterator(mock_websocket)
+        messages = [msg async for msg in iterator]
+
+        self.assertEqual(len(messages), 1)
+        self.assertEqual(messages[0], b"binary data")
+
+    async def test_yields_text_message(self):
+        mock_websocket = AsyncMock()
+        mock_websocket.receive.side_effect = [
+            {"type": "websocket.receive", "bytes": None, "text": "text data"},
+            {"type": "websocket.disconnect"},
+        ]
+
+        iterator = _WebSocketMessageIterator(mock_websocket)
+        messages = [msg async for msg in iterator]
+
+        self.assertEqual(len(messages), 1)
+        self.assertEqual(messages[0], "text data")
+
+    async def test_yields_mixed_messages(self):
+        mock_websocket = AsyncMock()
+        mock_websocket.receive.side_effect = [
+            {"type": "websocket.receive", "bytes": b"binary", "text": None},
+            {"type": "websocket.receive", "bytes": None, "text": "text"},
+            {"type": "websocket.receive", "bytes": b"more binary", "text": None},
+            {"type": "websocket.disconnect"},
+        ]
+
+        iterator = _WebSocketMessageIterator(mock_websocket)
+        messages = [msg async for msg in iterator]
+
+        self.assertEqual(len(messages), 3)
+        self.assertEqual(messages[0], b"binary")
+        self.assertEqual(messages[1], "text")
+        self.assertEqual(messages[2], b"more binary")
+
+    async def test_stops_on_disconnect(self):
+        mock_websocket = AsyncMock()
+        mock_websocket.receive.side_effect = [
+            {"type": "websocket.disconnect"},
+        ]
+
+        iterator = _WebSocketMessageIterator(mock_websocket)
+        messages = [msg async for msg in iterator]
+
+        self.assertEqual(len(messages), 0)
+
+
+if __name__ == "__main__":
+    unittest.main()