2 files changed, 15 insertions, 13 deletions

diff --git a/packages/order-watcher/src/order_watcher/order_watcher_websocket_server.ts b/packages/order-watcher/src/order_watcher/order_watcher_websocket_server.ts
index f90961cc8..da5667db3 100644
--- a/packages/order-watcher/src/order_watcher/order_watcher_websocket_server.ts
+++ b/packages/order-watcher/src/order_watcher/order_watcher_websocket_server.ts
@@ -105,20 +105,22 @@ export class OrderWatcherWebSocketServer {
 
     private async _onMessageCallbackAsync(connection: WebSocket.connection, message: any): Promise<void> {
         let response: WebSocketResponse;
-        assert.doesConformToSchema('message', message, schemas.orderWatcherWebSocketUtf8MessageSchema);
-        const request: WebSocketRequest = JSON.parse(message.utf8Data);
-        assert.doesConformToSchema('request', request, schemas.orderWatcherWebSocketRequestSchema);
-        assert.isString(request.jsonrpc, JSON_RPC_VERSION);
+        let id: number | null = null;
         try {
+            assert.doesConformToSchema('message', message, schemas.orderWatcherWebSocketUtf8MessageSchema);
+            const request: WebSocketRequest = JSON.parse(message.utf8Data);
+            id = request.id;
+            assert.doesConformToSchema('request', request, schemas.orderWatcherWebSocketRequestSchema);
+            assert.isString(request.jsonrpc, JSON_RPC_VERSION);
             response = {
-                id: request.id,
+                id,
                 jsonrpc: JSON_RPC_VERSION,
                 method: request.method,
                 result: await this._routeRequestAsync(request),
             };
         } catch (err) {
             response = {
-                id: request.id,
+                id,
                 jsonrpc: JSON_RPC_VERSION,
                 method: null,
                 error: err.toString(),
diff --git a/packages/order-watcher/src/types.ts b/packages/order-watcher/src/types.ts
index 536363d8a..2b529a939 100644
--- a/packages/order-watcher/src/types.ts
+++ b/packages/order-watcher/src/types.ts
@@ -48,21 +48,21 @@ export enum OrderWatcherMethod {
 // the data field of their WebSocket message to interact with the server.
 export type WebSocketRequest = AddOrderRequest | RemoveOrderRequest | GetStatsRequest;
 
-interface AddOrderRequest {
+export interface AddOrderRequest {
     id: number;
     jsonrpc: string;
     method: OrderWatcherMethod.AddOrder;
     params: { signedOrder: SignedOrder };
 }
 
-interface RemoveOrderRequest {
+export interface RemoveOrderRequest {
     id: number;
     jsonrpc: string;
     method: OrderWatcherMethod.RemoveOrder;
     params: { orderHash: string };
 }
 
-interface GetStatsRequest {
+export interface GetStatsRequest {
     id: number;
     jsonrpc: string;
     method: OrderWatcherMethod.GetStats;
@@ -72,21 +72,21 @@ interface GetStatsRequest {
 // of the WebSocket messages that the server sends out.
 export type WebSocketResponse = SuccessfulWebSocketResponse | ErrorWebSocketResponse;
 
-interface SuccessfulWebSocketResponse {
+export interface SuccessfulWebSocketResponse {
     id: number;
     jsonrpc: string;
     method: OrderWatcherMethod;
     result: OrderState | GetStatsResult | undefined; // result is undefined for ADD_ORDER and REMOVE_ORDER
 }
 
-interface ErrorWebSocketResponse {
-    id: number;
+export interface ErrorWebSocketResponse {
+    id: number | null;
     jsonrpc: string;
     method: null;
     error: JSONRPCError;
 }
 
-interface JSONRPCError {
+export interface JSONRPCError {
     code: number;
     message: string;
     data?: string | object;