feat: add error response type

Author: Taozizz

src/controllers/anthropicController.ts

@@ -61,7 +61,7 @@ export function handleMessage(req: Request, res: Response){
 		const response = createMessage(request);
 
 		//Check if it's an error response
-		if ('error' in response) {
+		if (response.type === 'error') {
 			return res.status(400).json(response);
 		}
 

src/services/anthropicService.ts

@@ -1,4 +1,4 @@
-import{ Model, ModelsResponse, MessagesRequest, MessagesResponse, Usage, MessageStartEvent, MessageDeltaEvent, MessageStopEvent,ContentBlockStartEvent, ContentBlockDeltaEvent} from '../types/anthropic';
+import{ Model, ModelsResponse, MessagesRequest, MessagesResponse, Usage, MessageStartEvent, MessageDeltaEvent, MessageStopEvent,ContentBlockStartEvent, ContentBlockDeltaEvent, ErrorResponse} from '../types/anthropic';
 
 import { anthropicMockModels } from '../data/anthropicMockData';
 import { getCurrentTimestamp, formatErrorResponse, calculateTokens, generateMessageId, findModelById, SSEMessageFormatter} from '../utils/anthropicHelpers';
@@ -24,7 +24,7 @@ export function getModels(): ModelsResponse {
 /**
  * Non-streaming response
  */
-export function createMessage(request: MessagesRequest): MessagesResponse{
+export function createMessage(request: MessagesRequest): MessagesResponse | ErrorResponse{
 	//Validate Model
 	const model = findModelById(request.model);
 	if(!model){

src/types/anthropic.ts

@@ -109,6 +109,14 @@ export interface MessagesResponse{
 	container: Container | null;
 }
 
+export interface ErrorResponse{
+	error: {
+		message: string,
+		type: string,
+	},
+	type: "error"
+}
+
 export interface MessageStartEvent{
 	type: 'message_start';
 	message: MessagesResponse;

src/utils/anthropicHelpers.ts

@@ -1,6 +1,6 @@
 import { MockModel } from "../types/index";
 import { anthropicMockModels } from "../data/anthropicMockData";
-import { StreamingEvent } from "../types/anthropic";
+import { ErrorResponse, StreamingEvent } from "../types/anthropic";
 
 /**
  * Get current timestamp
@@ -33,7 +33,7 @@ export function findModelById(modelId: string): MockModel | undefined {
 /**
  * Format error response
  */
-export function formatErrorResponse(message: string): any {
+export function formatErrorResponse(message: string): ErrorResponse {
   return {
     error: {
       message: message,