fix: allow creating forum threads with files

CHANGELOG.md

@@ -113,6 +113,8 @@ These changes are available on the `master` branch, but have not yet been releas
   ([#2048](https://github.com/Pycord-Development/pycord/pull/2048))
 - Fixed the Slash command syncronization method `indiviual`.
   ([#1925](https://github.com/Pycord-Development/pycord/pull/1925))
+- Fixed `HttpException` when trying to create a forum thread with files.
+  ([#2075](https://github.com/Pycord-Development/pycord/pull/2075))
 
 ## [2.4.1] - 2023-03-20
 

discord/channel.py

@@ -1274,53 +1274,25 @@ async def create_thread(
         if file is not None and files is not None:
             raise InvalidArgument("cannot pass both file and files parameter to send()")
 
-        if file is not None:
-            if not isinstance(file, File):
-                raise InvalidArgument("file parameter must be File")
-
-            try:
-                data = await state.http.send_files(
-                    self.id,
-                    files=[file],
-                    allowed_mentions=allowed_mentions,
-                    content=message_content,
-                    embed=embed,
-                    embeds=embeds,
-                    nonce=nonce,
-                    stickers=stickers,
-                    components=components,
-                )
-            finally:
-                file.close()
-
-        elif files is not None:
+        if files is not None:
             if len(files) > 10:
                 raise InvalidArgument(
                     "files parameter must be a list of up to 10 elements"
                 )
             elif not all(isinstance(file, File) for file in files):
                 raise InvalidArgument("files parameter must be a list of File")
 
-            try:
-                data = await state.http.send_files(
-                    self.id,
-                    files=files,
-                    content=message_content,
-                    embed=embed,
-                    embeds=embeds,
-                    nonce=nonce,
-                    allowed_mentions=allowed_mentions,
-                    stickers=stickers,
-                    components=components,
-                )
-            finally:
-                for f in files:
-                    f.close()
-        else:
+        if file is not None:
+            if not isinstance(file, File):
+                raise InvalidArgument("file parameter must be File")
+            files = [file]
+
+        try:
             data = await state.http.start_forum_thread(
                 self.id,
                 content=message_content,
                 name=name,
+                files=files,
                 embed=embed,
                 embeds=embeds,
                 nonce=nonce,
@@ -1333,6 +1305,11 @@ async def create_thread(
                 applied_tags=applied_tags,
                 reason=reason,
             )
+        finally:
+            if files is not None:
+                for f in files:
+                    f.close()
+
         ret = Thread(guild=self.guild, state=self._state, data=data)
         msg = ret.get_partial_message(data["last_message_id"])
         if view:

discord/http.py

@@ -1170,14 +1170,15 @@ def start_forum_thread(
         invitable: bool = True,
         applied_tags: SnowflakeList | None = None,
         reason: str | None = None,
+        files: Sequence[File] | None = None,
         embed: embed.Embed | None = None,
         embeds: list[embed.Embed] | None = None,
         nonce: str | None = None,
         allowed_mentions: message.AllowedMentions | None = None,
         stickers: list[sticker.StickerItem] | None = None,
         components: list[components.Component] | None = None,
     ) -> Response[threads.Thread]:
-        payload = {
+        payload: dict[str, Any] = {
             "name": name,
             "auto_archive_duration": auto_archive_duration,
             "invitable": invitable,
@@ -1208,13 +1209,37 @@ def start_forum_thread(
 
         if rate_limit_per_user:
             payload["rate_limit_per_user"] = rate_limit_per_user
+
+        form = [{"name": "payload_json"}]
+        if files:
+            attachments = []
+            for index, file in enumerate(files):
+                attachments.append(
+                    {
+                        "id": index,
+                        "filename": file.filename,
+                        "description": file.description,
+                    }
+                )
+                form.append(
+                    {
+                        "name": f"files[{index}]",
+                        "value": file.fp,
+                        "filename": file.filename,
+                        "content_type": "application/octet-stream",
+                    }
+                )
+            payload["attachments"] = attachments
+
+        form[0]["value"] = utils._to_json(payload)
+
         # TODO: Once supported by API, remove has_message=true query parameter
         route = Route(
             "POST",
             "/channels/{channel_id}/threads?has_message=true",
             channel_id=channel_id,
         )
-        return self.request(route, json=payload, reason=reason)
+        return self.request(route, form=form, reason=reason)
 
     def join_thread(self, channel_id: Snowflake) -> Response[None]:
         return self.request(