[V3 Core] Add optional async setup function (#1314)

redbot/core/bot.py

@@ -172,7 +172,7 @@ class RedBase(BotBase, RpcMethodMixin):
             while pkg_name in curr_pkgs:
                 curr_pkgs.remove(pkg_name)
 
-    def load_extension(self, spec: ModuleSpec):
+    async def load_extension(self, spec: ModuleSpec):
         name = spec.name.split('.')[-1]
         if name in self.extensions:
             return
@@ -182,7 +182,11 @@ class RedBase(BotBase, RpcMethodMixin):
             del lib
             raise discord.ClientException('extension does not have a setup function')
 
-        lib.setup(self)
+        if asyncio.iscoroutinefunction(lib.setup):
+            await lib.setup(self)
+        else:
+            lib.setup(self)
+
         self.extensions[name] = lib
 
     def unload_extension(self, name):

redbot/core/core_commands.py

@@ -226,7 +226,7 @@ class Core:
             return
 
         try:
-            ctx.bot.load_extension(spec)
+            await ctx.bot.load_extension(spec)
         except Exception as e:
             log.exception("Package loading failed", exc_info=e)
             await ctx.send(_("Failed to load package. Check your console or "
@@ -261,7 +261,7 @@ class Core:
 
         try:
             self.cleanup_and_refresh_modules(spec.name)
-            ctx.bot.load_extension(spec)
+            await ctx.bot.load_extension(spec)
         except Exception as e:
             log.exception("Package reloading failed", exc_info=e)
             await ctx.send(_("Failed to reload package. Check your console or "

redbot/core/events.py

@@ -52,7 +52,7 @@ def init_events(bot, cli_flags):
             for package in packages:
                 try:
                     spec = await bot.cog_mgr.find_cog(package)
-                    bot.load_extension(spec)
+                    await bot.load_extension(spec)
                 except Exception as e:
                     log.exception("Failed to load package {}".format(package),
                                   exc_info=e)