handling of errors on read_web

meme_otron/meme_otron.py

@@ -72,12 +72,10 @@ def compute_part(*args: str, input_data: Optional[bytes] = None,
         if input_data is None or len(input_data) == 0:
             if len(args) <= 1:
                 return None, 'Image: received no input data nor URL'
-            elif not utils.validate_url(args[1]):
-                return None, 'Image: invalid URL format'
             else:
-                input_data = utils.read_web(args[1])
+                input_data, err = utils.read_web(args[1])
                 if input_data is None:
-                    return None, 'Image: could not reach URL'
+                    return None, 'Image: ' + err
         img = img_factory.build_image_only(input_data)
         if img is None:
             return None, 'Image: invalid image format'

meme_otron/utils.py

@@ -235,12 +235,19 @@ def read_stream(stream: BinaryIO) -> bytes:
     return output_data
 
 
-def read_web(url: str, timeout: int = 5) -> Optional[bytes]:
+def read_web(url: str, *, timeout: int = 5,
+             max_file_size: Optional[int] = None) -> Tuple[Optional[bytes], Optional[str]]:
+    if not validate_url(url):
+        return None, 'Invalid URL'
     try:
         with urlopen(url, None, timeout) as web_file:
-            return web_file.read()
+            if web_file.getcode() != 200:
+                return None, 'Invalid return code'
+            if max_file_size is not None and int(web_file.info()['Content-Length']) > max_file_size:
+                return None, 'File too big'
+            return web_file.read(), None
     except URLError:
-        return None
+        return None, 'Could not connect'
 
 
 # endregion