From 92287c0a9a18f022c90a3364ae185ae921359b8e Mon Sep 17 00:00:00 2001
From: Jamie Brunton <jamie@jbrunton.co.uk>
Date: Sat, 8 Aug 2026 15:40:55 +0100
Subject: [PATCH] Stop Matrix refresh loop when login is unavailable

---
 src/services/chat/service.ts                | 22 ++++++++-
 tests/chat-service-username-persist.test.ts | 54 ++++++++++++++++++++-
 2 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/src/services/chat/service.ts b/src/services/chat/service.ts
index 3a324f0..0506e67 100644
--- a/src/services/chat/service.ts
+++ b/src/services/chat/service.ts
@@ -25,6 +25,13 @@ export interface TokenRefresher {
   refresh(): Promise<void>;
 }
 
+class MatrixAuthenticationUnavailableError extends Error {
+  constructor(cause: unknown) {
+    super('Matrix authentication could not be restored', { cause });
+    this.name = 'MatrixAuthenticationUnavailableError';
+  }
+}
+
 /**
  * Optional Reddit-API hook for resolving t2 IDs to real usernames. Without
  * it, conversations show up as `t2_abc123` (stable but ugly). With it, the
@@ -174,7 +181,11 @@ export class ChatService {
     } catch (err) {
       if (err instanceof MatrixAuthError && this.tokenRefresher) {
         this.logger.warn('[chat] Matrix token rejected — refreshing via browser session');
-        await this.tokenRefresher.refresh();
+        try {
+          await this.tokenRefresher.refresh();
+        } catch (refreshError) {
+          throw new MatrixAuthenticationUnavailableError(refreshError);
+        }
         return await fn();
       }
       throw err;
@@ -331,6 +342,7 @@ export class ChatService {
           try {
             await this.loadDetails(chat);
           } catch (err) {
+            if (err instanceof MatrixAuthenticationUnavailableError) throw err;
             this.logger.error(`[chat] backfill: failed details for ${chat.roomName}`, err);
           }
           done++;
@@ -1062,6 +1074,10 @@ export class ChatService {
         }) as { state_key?: string } | undefined;
         t2 = otherMember?.state_key?.match(/^@(t2_[^:]+):/)?.[1];
       } catch (err) {
+        if (err instanceof MatrixAuthenticationUnavailableError) {
+          this.logger.warn('[chat] username enrichment paused until Reddit login is restored');
+          return;
+        }
         this.logger.debug(`[chat] /state lookup failed for ${chat.roomId}:`, err);
       }
       if (!t2) {
@@ -1074,6 +1090,10 @@ export class ChatService {
           )?.sender;
           t2 = otherSender?.match(/^@(t2_[^:]+):/)?.[1];
         } catch (err) {
+          if (err instanceof MatrixAuthenticationUnavailableError) {
+            this.logger.warn('[chat] username enrichment paused until Reddit login is restored');
+            return;
+          }
           this.logger.debug(`[chat] /messages lookup failed for ${chat.roomId}:`, err);
         }
       }
diff --git a/tests/chat-service-username-persist.test.ts b/tests/chat-service-username-persist.test.ts
index a504b5a..afefccb 100644
--- a/tests/chat-service-username-persist.test.ts
+++ b/tests/chat-service-username-persist.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect } from 'vitest';
+import { describe, it, expect, vi } from 'vitest';
 import os from 'os';
 import path from 'path';
 import Database from 'better-sqlite3';
@@ -6,7 +6,7 @@ import { runMigrations } from '../src/database/client.js';
 import { RedditUsersRepository } from '../src/database/repositories.js';
 import { ChatService } from '../src/services/chat/service.js';
 import { ChatCache } from '../src/services/chat/cache.js';
-import { MatrixClient } from '../src/services/chat/matrix/client.js';
+import { MatrixAuthError, MatrixClient } from '../src/services/chat/matrix/client.js';
 import { createMockLogger } from './mockLogger.js';
 
 const creds = {
@@ -103,4 +103,54 @@ describe('ChatService username persistence', () => {
     expect(chats[0].roomName).toBe('alice');
     db.close();
   });
+
+  it('aborts username enrichment after one failed token refresh', async () => {
+    const logger = createMockLogger();
+    const cache = tmpCache(logger);
+    cache.set([
+      {
+        username: 'unknown',
+        roomName: 'unknown',
+        lastMessageTime: Date.now(),
+        lastMessageSnippet: '',
+        isFromUs: false,
+        unread: false,
+        roomId: '!first:reddit.com',
+        messages: [],
+      },
+      {
+        username: 'unknown',
+        roomName: 'unknown',
+        lastMessageTime: Date.now(),
+        lastMessageSnippet: '',
+        isFromUs: false,
+        unread: false,
+        roomId: '!second:reddit.com',
+        messages: [],
+      },
+    ]);
+
+    const matrix = buildMatrix();
+    matrix.getRoomFullState = vi.fn().mockRejectedValue(new MatrixAuthError('expired'));
+    matrix.getRoomMessages = vi.fn().mockRejectedValue(new MatrixAuthError('expired'));
+    const tokenRefresher = {
+      refresh: vi.fn().mockRejectedValue(new Error('interactive login required')),
+    };
+    const usernameResolver = { resolveT2Ids: vi.fn().mockResolvedValue({}) };
+    const svc = new ChatService(
+      matrix,
+      logger,
+      undefined,
+      undefined,
+      tokenRefresher,
+      usernameResolver,
+      cache,
+    );
+
+    await svc.enrichUsernames();
+
+    expect(tokenRefresher.refresh).toHaveBeenCalledOnce();
+    expect(matrix.getRoomFullState).toHaveBeenCalledOnce();
+    expect(matrix.getRoomMessages).not.toHaveBeenCalled();
+  });
 });