[ABSTRACT] Abstract the PNG sending code.

main.py

@@ -4,33 +4,45 @@ import asyncio
 import yaml
 import os
 
-# Our message callback. It should be passed through a router.
-async def msg_cb(room: MatrixRoom, event: RoomMessageText) -> None:
-    if event.body.startswith("$"):
-        import imagesize
-        import latex
 
-        try: 
-            filename = latex.render("", event.body)
+async def send_png(room: MatrixRoom, filename: str) -> None:
+    import imagesize
+    basename = os.path.basename(filename)
     w, h = imagesize.get(filename)
 
     file = open(filename, "r+b")
     size = os.path.getsize(filename)
 
     filename = os.path.basename(filename)
-            resp, keys = await client.upload(file, content_type="image/png", filename=filename)
+    resp, keys = await client.upload(file, content_type="image/png", filename=basename)
+
+    if not isinstance(resp, UploadResponse):
+        raise OSError("Couldn't upload file.")
+
     content = {
-                "body": filename,
+        "body": basename,
         "info": {
             "size": size,
-                    "w": w, "h": h,
-                    "mimetype": "image/png"
+            "mimetype": "image/png",
+            "w": w, "h": h
         },
         "msgtype": "m.image",
         "url": resp.content_uri,
     }
+    file.close()
+
     await client.room_send(room.room_id, message_type="m.room.message", content=content)
-        except FileNotFoundError:
+
+
+# Our message callback. It should be passed through a router.
+async def msg_cb(room: MatrixRoom, event: RoomMessageText) -> None:
+    if event.body.startswith("$"):
+        import latex
+
+        try:
+            filename = latex.render("", event.body)
+            await send_png(room, filename)
+        except (FileNotFoundError, OSError):
             content = {
                 "msgtype": "m.text",
                 "body": "Couldn't parse LaTeX correctly."