fix: Resolve ENAMETOOLONG errors with Korean chat titles and implement filename safety

src/database/json/chat/ChatManager.test.ts

@@ -3,6 +3,14 @@ import { App } from 'obsidian'
 import { ChatManager } from './ChatManager'
 import { CHAT_SCHEMA_VERSION, ChatConversation } from './types'
 
+// Mock path-browserify module
+jest.mock('path-browserify', () => ({
+  default: {
+    join: (...args: string[]) => args.join('/'),
+    basename: (path: string) => path.split('/').pop() || '',
+  }
+}))
+
 const mockAdapter = {
   exists: jest.fn().mockResolvedValue(true),
   mkdir: jest.fn().mockResolvedValue(undefined),
@@ -24,6 +32,11 @@ describe('ChatManager', () => {
   let chatManager: ChatManager
 
   beforeEach(() => {
+    // Reset mocks before each test
+    jest.clearAllMocks()
+    mockAdapter.exists.mockResolvedValue(false) // Default to file not existing
+    mockAdapter.list.mockResolvedValue({ files: [], folders: [] })
+
     chatManager = new ChatManager(mockApp)
   })
 
@@ -71,9 +84,112 @@ describe('ChatManager', () => {
       expect(metadata).not.toBeNull()
       if (metadata) {
         expect(metadata.id).toBe(chat.id)
-        expect(metadata.title).toBe(chat.title)
         expect(metadata.updatedAt).toBe(chat.updatedAt)
         expect(metadata.schemaVersion).toBe(chat.schemaVersion)
+
+        // For very long titles or those with hashing, the title might be truncated
+        // In such cases, we expect 'Loading...' as a placeholder
+        if (title.length > 50 || encodeURIComponent(title).length > 50) {
+          // Long titles should either be truncated or show 'Loading...'
+          expect(metadata.title === 'Loading...' || metadata.title.length <= title.length).toBe(true)
+        } else {
+          // Short titles should roundtrip exactly
+          expect(metadata.title).toBe(chat.title)
+        }
+      }
+    })
+  })
+
+  describe('filename length safety', () => {
+    test('should generate filenames within length limits', () => {
+      const veryLongTitle = 'This is an extremely long title that would normally cause ENAMETOOLONG errors when encoded as a filename because it contains many characters including special characters like 한글 and emojis 🚀🔥 and lots of other text that makes it very very long indeed'
+
+      const chat: ChatConversation = {
+        id: '123e4567-e89b-12d3-a456-426614174000',
+        title: veryLongTitle,
+        messages: [],
+        createdAt: 1620000000000,
+        updatedAt: 1620000000000,
+        schemaVersion: CHAT_SCHEMA_VERSION,
+      }
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const fileName = (chatManager as any).generateFileName(chat)
+
+      // Filename should be within safe length limits
+      expect(fileName.length).toBeLessThan(200)
+      expect(fileName).toMatch(/^v\d+_.*_\d+_[0-9a-f-]+\.json$/)
+    })
+
+    test('should handle Korean characters that expand when encoded', () => {
+      const koreanTitle = 'MoC 에서 적절한 MoC 1~2개를 추천해주고 @README.md 가이드를 참고해'
+
+      const chat: ChatConversation = {
+        id: '123e4567-e89b-12d3-a456-426614174000',
+        title: koreanTitle,
+        messages: [],
+        createdAt: 1620000000000,
+        updatedAt: 1620000000000,
+        schemaVersion: CHAT_SCHEMA_VERSION,
+      }
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const fileName = (chatManager as any).generateFileName(chat)
+
+      // Should be safe length despite Korean encoding expansion
+      expect(fileName.length).toBeLessThan(200)
+      expect(fileName).toMatch(/^v\d+_.*_\d+_[0-9a-f-]+\.json$/)
+    })
+  })
+
+  describe('title validation and sanitization', () => {
+    test('should sanitize overly long titles', async () => {
+      const veryLongTitle = 'A'.repeat(150) // 150 characters
+
+      const chat = await chatManager.createChat({ title: veryLongTitle })
+
+      // Title should be truncated to max length with ellipsis
+      expect(chat.title.length).toBeLessThanOrEqual(100)
+      expect(chat.title.endsWith('...')).toBe(true)
+    })
+
+    test('should throw error for empty titles', async () => {
+      await expect(chatManager.createChat({ title: '' })).rejects.toThrow()
+      await expect(chatManager.createChat({ title: '   ' })).rejects.toThrow()
+    })
+
+    test('should trim whitespace from titles', async () => {
+      const chat = await chatManager.createChat({ title: '  Test Title  ' })
+
+      expect(chat.title).toBe('Test Title')
+    })
+
+    test('should validate titles during updates', async () => {
+      // Create a chat first
+      const chat = await chatManager.createChat({ title: 'Original Title' })
+
+      // Generate the actual filename that would be created
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const actualFileName = (chatManager as any).generateFileName(chat)
+
+      // Mock the file listing to find our chat
+      // The list method returns full paths, basename extracts the filename
+      mockAdapter.list.mockResolvedValue({
+        files: [`.smtcmp_json_db/chats/${actualFileName}`],
+        folders: []
+      })
+
+      // Mock reading the chat file
+      mockAdapter.read.mockResolvedValue(JSON.stringify(chat))
+
+      const longTitle = 'B'.repeat(150)
+
+      const updatedChat = await chatManager.updateChat(chat.id, { title: longTitle })
+
+      expect(updatedChat).not.toBeNull()
+      if (updatedChat) {
+        expect(updatedChat.title.length).toBeLessThanOrEqual(100)
+        expect(updatedChat.title.endsWith('...')).toBe(true)
       }
     })
   })