fix(line): map LINE image messages to photos (#38235)

plugins/platforms/line/adapter.py

@@ -133,6 +133,22 @@
 LINE_IMAGE_MAX_BYTES = 10 * 1024 * 1024  # 10 MB per LINE docs
 LINE_AV_MAX_BYTES = 200 * 1024 * 1024  # 200 MB for voice/video
 
+_LINE_MESSAGE_TYPES = {
+    "text": MessageType.TEXT,
+    "image": MessageType.PHOTO,
+    "audio": MessageType.AUDIO,
+    "video": MessageType.VIDEO,
+    "file": MessageType.DOCUMENT,
+    "sticker": MessageType.STICKER,
+    "location": MessageType.LOCATION,
+}
+
+
+def _line_msg_type(line_type: str) -> MessageType:
+    """Map a LINE webhook message type to Hermes' canonical message type."""
+    return _LINE_MESSAGE_TYPES.get(line_type, MessageType.TEXT)
+
+
 # A 1×1 transparent PNG used as fallback video preview thumbnail when no
 # explicit preview is supplied — LINE requires ``previewImageUrl`` for
 # video messages. Sourced from the Python stdlib (no Pillow dependency).
@@ -968,7 +984,7 @@ async def _handle_message_event(self, event: Dict[str, Any]) -> None:
 
         event_obj = MessageEvent(
             text=text,
-            message_type=MessageType.TEXT if msg_type == "text" else MessageType.IMAGE,
+            message_type=_line_msg_type(msg_type),
             source=source_obj,
             raw_message=event,
             message_id=message_id,

tests/plugins/test_line_adapter.py

@@ -0,0 +1,30 @@
+"""Regression tests for LINE inbound MessageType mapping."""
+
+from gateway.platforms.base import MessageEvent, MessageType
+from plugins.platforms.line.adapter import _line_msg_type
+
+
+def test_line_image_messages_map_to_photo_message_type():
+    """LINE sends type='image', but Hermes uses MessageType.PHOTO."""
+    event = MessageEvent(
+        text="[image]",
+        message_type=_line_msg_type("image"),
+        source=None,  # type: ignore[arg-type]
+    )
+
+    assert not hasattr(MessageType, "IMAGE")
+    assert event.message_type is MessageType.PHOTO
+
+
+def test_line_non_text_message_types_map_to_existing_message_types():
+    assert _line_msg_type("text") is MessageType.TEXT
+    assert _line_msg_type("audio") is MessageType.AUDIO
+    assert _line_msg_type("video") is MessageType.VIDEO
+    assert _line_msg_type("file") is MessageType.DOCUMENT
+    assert _line_msg_type("sticker") is MessageType.STICKER
+    assert _line_msg_type("location") is MessageType.LOCATION
+
+
+def test_line_unknown_message_types_default_to_text():
+    assert _line_msg_type("poll") is MessageType.TEXT
+    assert _line_msg_type("") is MessageType.TEXT