Handle 400 when setting pre-existing doc package

If you run, for example:

    !doc setdoc black https://black.readthedocs/en/stable/objects.inv

twice over. You'll get an unhelpful "According to the API, your request
is malformed." error message back. This commit adds an error handler
to catch the HTTP 400 and tell the user the package already exists.

1 files changed, 9 insertions, 1 deletions

diff --git a/bot/exts/info/doc/_cog.py b/bot/exts/info/doc/_cog.py
index e7710db24..7d63bc9a9 100644
--- a/bot/exts/info/doc/_cog.py
+++ b/bot/exts/info/doc/_cog.py
@@ -13,6 +13,7 @@ import aiohttp
 import discord
 from discord.ext import commands
 
+from bot.api import ResponseCodeError
 from bot.bot import Bot
 from bot.constants import MODERATION_ROLES, RedirectOutput
 from bot.converters import Inventory, PackageName, ValidURL, allowed_strings
@@ -395,7 +396,14 @@ class DocCog(commands.Cog):
             "base_url": base_url,
             "inventory_url": inventory_url
         }
-        await self.bot.api_client.post("bot/documentation-links", json=body)
+        try:
+            await self.bot.api_client.post("bot/documentation-links", json=body)
+        except ResponseCodeError as err:
+            if err.status == 400 and "already exists" in err.response_json.get("package", [""])[0]:
+                log.info(f"Ignoring HTTP 400 as package {package_name} has already been added.")
+                await ctx.send(f"Package {package_name} has already already added.")
+                return
+            raise
 
         log.info(
             f"User @{ctx.author} ({ctx.author.id}) added a new documentation package:\n"