fix(commands): /kick and /ban failures are no longer silent (#216)

rateLimitedActions now collects non-429 failures (and a 429 that exhausted its
retries) and returns them instead of swallowing them; existing callers ignore
the return. /kick and /ban turn the list into a CommandError whose message
names who and why, using the server's own sentence (MatrixError.data.error),
never the URL-bearing toString(); RoomInput's toast shows it verbatim.

Verified headless as a non-moderator: '/kick @alice' → "Could not kick
@alice:localhost: You cannot kick user @alice:localhost."; '/ban @nobody
@alice' → "Could not ban @nobody:localhost, @alice:localhost: You don't have
permission to ban".

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/room/RoomInput.tsx

@@ -113,7 +113,14 @@ import {
 } from './msgContent';
 import { getMemberName, getMentionContent, trimReplyFromBody } from '../../utils/room';
 import { CommandAutocomplete } from './CommandAutocomplete';
-import { Command, SHRUG, TABLEFLIP, UNFLIP, useCommands } from '../../hooks/useCommands';
+import {
+  Command,
+  CommandError,
+  SHRUG,
+  TABLEFLIP,
+  UNFLIP,
+  useCommands,
+} from '../../hooks/useCommands';
 import { mobileOrTablet } from '../../utils/user-agent';
 import { useElementSizeObserver } from '../../hooks/useElementSizeObserver';
 import { ReplyLayout, ThreadIndicator } from '../../components/message';
@@ -665,16 +672,16 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
         const commandContent = commands[commandName as Command];
         if (commandContent) {
           // Fire-and-forget by design (the editor resets immediately for UX), but
-          // surface a rejection instead of failing silently. NOTE: /kick and /ban
-          // route through rateLimitedActions (utils/matrix.ts), whose to() helper
-          // swallows non-429 errors, so those two commands can still resolve even
-          // when the underlying kick/ban failed — this catch only covers errors
-          // that actually reject out of exe().
+          // surface a rejection instead of failing silently. /kick and /ban
+          // throw a CommandError whose message already names who and why
+          // (#216); anything else gets the generic sentence.
           commandContent.exe(plainText).catch((err) => {
             console.error(`Failed to run /${commandName} command:`, err);
             setToast(
               createErrorToast(
-                `The /${commandName} command failed. Please try again.`,
+                err instanceof CommandError
+                  ? err.message
+                  : `The /${commandName} command failed. Please try again.`,
                 Icons.Warning,
                 'Command failed',
               ),

src/app/hooks/useCommands.ts

@@ -20,6 +20,7 @@ import {
   isServerName,
   isUserId,
   rateLimitedActions,
+  RateLimitedFailure,
   removeRoomIdFromMDirect,
 } from '../utils/matrix';
 import { useRoomNavigate } from './useRoomNavigate';
@@ -138,6 +139,28 @@ export const parseTimestampFlag = (input: string): number | undefined => {
 
 export type CommandExe = (payload: string) => Promise<void>;
 
+/**
+ * [Gitea #216] A command that partially or fully failed. `message` is written
+ * for the user (the RoomInput toast shows it verbatim).
+ */
+export class CommandError extends Error {}
+
+const throwCommandFailures = (
+  verb: 'kick' | 'ban',
+  failures: RateLimitedFailure<string>[],
+): void => {
+  if (failures.length === 0) return;
+  const who = failures.map((f) => f.item).join(', ');
+  // MatrixError.data.error is the server's sentence ("You don't have
+  // permission to kick"); fall back to the errcode, never the URL-bearing
+  // toString().
+  const reason =
+    (failures[0].error.data as { error?: string } | undefined)?.error ??
+    failures[0].error.errcode ??
+    'unknown error';
+  throw new CommandError(`Could not ${verb} ${who}: ${reason}`);
+};
+
 export enum Command {
   Me = 'me',
   Notice = 'notice',
@@ -292,11 +315,13 @@ export const useCommands = (mx: MatrixClient, room: Room): CommandRecord => {
             });
           }
 
-          // NOTE: rateLimitedActions' to() helper (utils/matrix.ts) swallows every
-          // non-429 error, so a failed kick (e.g. insufficient power level) resolves
-          // silently here — the RoomInput exe() catch cannot surface it. Propagating
-          // would require refactoring rateLimitedActions' shared error handling.
-          await rateLimitedActions(users, (id) => mx.kick(room.roomId, id, reason));
+          // [Gitea #216] rateLimitedActions collects per-user failures (it
+          // used to swallow them); turn them into one CommandError so the
+          // RoomInput toast can say who and why.
+          const { failures } = await rateLimitedActions(users, (id) =>
+            mx.kick(room.roomId, id, reason),
+          );
+          throwCommandFailures('kick', failures);
         },
       },
       [Command.Ban]: {
@@ -318,9 +343,10 @@ export const useCommands = (mx: MatrixClient, room: Room): CommandRecord => {
             });
           }
 
-          // See the /kick note: rateLimitedActions swallows non-429 errors, so a
-          // failed ban resolves silently and can't be surfaced by the exe() catch.
-          await rateLimitedActions(users, (id) => mx.ban(room.roomId, id, reason));
+          const { failures } = await rateLimitedActions(users, (id) =>
+            mx.ban(room.roomId, id, reason),
+          );
+          throwCommandFailures('ban', failures);
         },
       },
       [Command.UnBan]: {

src/app/utils/matrix.ts

@@ -467,15 +467,24 @@ export const declineInvite = async (mx: MatrixClient, roomId: string): Promise<v
   await mx.forget(roomId).catch(() => undefined);
 };
 
+export type RateLimitedFailure<T> = { item: T; error: MatrixError };
+
+/**
+ * Run `callback` over `data` sequentially, backing off on 429. Other errors do
+ * not stop the loop — they are collected and returned so callers can tell the
+ * user which items failed (a failed /kick used to vanish silently, #216).
+ */
 export const rateLimitedActions = async <T, R = void>(
   data: T[],
   callback: (item: T, index: number) => Promise<R>,
   maxRetryCount?: number,
-) => {
+): Promise<{ failures: RateLimitedFailure<T>[] }> => {
   let retryCount = 0;
 
   let actionInterval = 0;
 
+  const failures: RateLimitedFailure<T>[] = [];
+
   const sleepForMs = (ms: number) =>
     new Promise((resolve) => {
       setTimeout(resolve, ms);
@@ -486,6 +495,7 @@ export const rateLimitedActions = async <T, R = void>(
 
     if (err?.httpStatus === 429) {
       if (retryCount === maxRetryCount) {
+        failures.push({ item: dataItem, error: err });
         return;
       }
 
@@ -496,6 +506,8 @@ export const rateLimitedActions = async <T, R = void>(
       retryCount += 1;
 
       await performAction(dataItem, index);
+    } else if (err) {
+      failures.push({ item: dataItem, error: err });
     }
   };
 
@@ -509,6 +521,7 @@ export const rateLimitedActions = async <T, R = void>(
       await sleepForMs(actionInterval);
     }
   }
+  return { failures };
 };
 
 export const knockSupported = (version: string): boolean => {