Improve latency feedback

app/modules/latency.py

@@ -11,14 +11,24 @@ class LatencyModule(niobot.Module):
     async def latency(self, ctx: niobot.Context, homeserver: str = None):
         """
         See the bot's latency.
-        
+
         If you supply a homeserver, it will also show the federation latency to that homeserver.
         """
         latency = ctx.latency
 
-        homeserver = homeserver or ctx.message.sender.split(":")[1]
-        if not homeserver.startswith("http"):
-            homeserver = f"https://{homeserver}"
+        response = await ctx.respond(
+            "Latency: {:,.2f}ms{}".format(
+                latency,
+                " (pinging homeserver...)"
+                if homeserver
+                else ''
+            )
+        )
+        if homeserver:
+            if not homeserver.startswith("http"):
+                homeserver = f"https://{homeserver}"
+        else:
+            return
 
         parsed = urllib.parse.urlparse(homeserver)
         loc = "https://" + parsed.netloc
@@ -44,6 +54,12 @@ class LatencyModule(niobot.Module):
                 else:
                     end = time.perf_counter()
                     timings.append(end - start)
+            if sum(timings) == -5:
+                return await response.edit(
+                    "Latency: {:,.2f}ms (failed to connect to homeserver)".format(
+                        latency
+                    )
+                )
             fed_latency = sum(timings) / len(timings) * 1000
 
         hs_target = homeserver[8:]