feat: improve error messages (#1006)

lib/errors.ts

@@ -0,0 +1,132 @@
+export type ErrorType =
+  | 'bad_request'
+  | 'unauthorized'
+  | 'forbidden'
+  | 'not_found'
+  | 'rate_limit'
+  | 'offline';
+
+export type Surface =
+  | 'chat'
+  | 'auth'
+  | 'api'
+  | 'stream'
+  | 'database'
+  | 'history'
+  | 'vote'
+  | 'document'
+  | 'suggestions';
+
+export type ErrorCode = `${ErrorType}:${Surface}`;
+
+export type ErrorVisibility = 'response' | 'log' | 'none';
+
+export const visibilityBySurface: Record<Surface, ErrorVisibility> = {
+  database: 'log',
+  chat: 'response',
+  auth: 'response',
+  stream: 'response',
+  api: 'response',
+  history: 'response',
+  vote: 'response',
+  document: 'response',
+  suggestions: 'response',
+};
+
+export class ChatSDKError extends Error {
+  public type: ErrorType;
+  public surface: Surface;
+  public statusCode: number;
+
+  constructor(errorCode: ErrorCode, cause?: string) {
+    super();
+
+    const [type, surface] = errorCode.split(':');
+
+    this.type = type as ErrorType;
+    this.cause = cause;
+    this.surface = surface as Surface;
+    this.message = getMessageByErrorCode(errorCode);
+    this.statusCode = getStatusCodeByType(this.type);
+  }
+
+  public toResponse() {
+    const code: ErrorCode = `${this.type}:${this.surface}`;
+    const visibility = visibilityBySurface[this.surface];
+
+    const { message, cause, statusCode } = this;
+
+    if (visibility === 'log') {
+      console.error({
+        code,
+        message,
+        cause,
+      });
+
+      return Response.json(
+        { code: '', message: 'Something went wrong. Please try again later.' },
+        { status: statusCode },
+      );
+    }
+
+    return Response.json({ code, message, cause }, { status: statusCode });
+  }
+}
+
+export function getMessageByErrorCode(errorCode: ErrorCode): string {
+  if (errorCode.includes('database')) {
+    return 'An error occurred while executing a database query.';
+  }
+
+  switch (errorCode) {
+    case 'bad_request:api':
+      return "The request couldn't be processed. Please check your input and try again.";
+
+    case 'unauthorized:auth':
+      return 'You need to sign in before continuing.';
+    case 'forbidden:auth':
+      return 'Your account does not have access to this feature.';
+
+    case 'rate_limit:chat':
+      return 'You have exceeded your maximum number of messages for the day. Please try again later.';
+    case 'not_found:chat':
+      return 'The requested chat was not found. Please check the chat ID and try again.';
+    case 'forbidden:chat':
+      return 'This chat belongs to another user. Please check the chat ID and try again.';
+    case 'unauthorized:chat':
+      return 'You need to sign in to view this chat. Please sign in and try again.';
+    case 'offline:chat':
+      return "We're having trouble sending your message. Please check your internet connection and try again.";
+
+    case 'not_found:document':
+      return 'The requested document was not found. Please check the document ID and try again.';
+    case 'forbidden:document':
+      return 'This document belongs to another user. Please check the document ID and try again.';
+    case 'unauthorized:document':
+      return 'You need to sign in to view this document. Please sign in and try again.';
+    case 'bad_request:document':
+      return 'The request to create or update the document was invalid. Please check your input and try again.';
+
+    default:
+      return 'Something went wrong. Please try again later.';
+  }
+}
+
+function getStatusCodeByType(type: ErrorType) {
+  switch (type) {
+    case 'bad_request':
+      return 400;
+    case 'unauthorized':
+      return 401;
+    case 'forbidden':
+      return 403;
+    case 'not_found':
+      return 404;
+    case 'rate_limit':
+      return 429;
+    case 'offline':
+      return 503;
+    default:
+      return 500;
+  }
+}