Extracted multiple send calls logic into decorator

Author: michalpokusa

adafruit_httpserver/exceptions.py

@@ -34,7 +34,7 @@ def __init__(self, path: str) -> None:
         super().__init__(f"Backslash in path: {path}")
 
 
-class ResponseAlreadySentException(Exception):
+class ResponseAlreadySentError(Exception):
     """
     Another ``HTTPResponse`` has already been sent. There can only be one per ``HTTPRequest``.
     """

adafruit_httpserver/response.py

@@ -21,7 +21,7 @@
     BackslashInPathError,
     FileNotExistsError,
     ParentDirectoryReferenceError,
-    ResponseAlreadySentException,
+    ResponseAlreadySentError,
 )
 from .mime_type import MIMEType
 from .request import HTTPRequest
@@ -147,6 +147,21 @@ def _send_headers(
             self.request.connection, response_message_header.encode("utf-8")
         )
 
+    def _prevent_multiple_send_calls(function):
+        """
+        Decorator that prevents calling `send` or `send_file` more than once.
+        """
+
+        def wrapper(self: HTTPResponse, *args, **kwargs):
+            if self._response_already_sent:
+                raise ResponseAlreadySentError
+
+            result = function(self, *args, **kwargs)
+            return result
+
+        return wrapper
+
+    @_prevent_multiple_send_calls
     def send(
         self,
         body: str = "",
@@ -158,8 +173,6 @@ def send(
 
         Should be called **only once** per response.
         """
-        if self._response_already_sent:
-            raise ResponseAlreadySentException
 
         if getattr(body, "encode", None):
             encoded_response_message_body = body.encode("utf-8")
@@ -200,6 +213,7 @@ def _get_file_length(file_path: str) -> int:
         except OSError:
             raise FileNotExistsError(file_path)  # pylint: disable=raise-missing-from
 
+    @_prevent_multiple_send_calls
     def send_file(
         self,
         filename: str = "index.html",
@@ -214,8 +228,6 @@ def send_file(
 
         Should be called **only once** per response.
         """
-        if self._response_already_sent:
-            raise ResponseAlreadySentException
 
         if safe:
             self._check_file_path_is_valid(filename)