allowed returning JSONObject from error handler

Author: sdangol

packages/event-handler/src/rest/Router.ts

@@ -327,14 +327,11 @@ class Router {
           }
         }
         return new Response(JSON.stringify(body), {
-          status: body.statusCode,
+          status: (body.statusCode as number) ?? HttpErrorCodes.OK,
           headers: { 'Content-Type': 'application/json' },
         });
       } catch (handlerError) {
-        if (handlerError instanceof NotFoundError) {
-          return await this.handleError(handlerError, options);
-        }
-        if (handlerError instanceof MethodNotAllowedError) {
+        if (handlerError instanceof ServiceError) {
           return await this.handleError(handlerError, options);
         }
         return this.#defaultErrorHandler(handlerError as Error);

packages/event-handler/src/types/rest.ts

@@ -40,8 +40,11 @@ type ErrorHandler<T extends Error = Error> = T extends
   ? (
       error: T,
       reqCtx: RequestContext
-    ) => Promise<Omit<ErrorResponse, 'statusCode'> | Response>
-  : (error: T, reqCtx: RequestContext) => Promise<ErrorResponse | Response>;
+    ) => Promise<Omit<ErrorResponse, 'statusCode'> | Response | JSONObject>
+  : (
+      error: T,
+      reqCtx: RequestContext
+    ) => Promise<ErrorResponse | Response | JSONObject>;
 
 interface ErrorConstructor<T extends Error = Error> {
   new (...args: any[]): T;

packages/event-handler/tests/unit/rest/Router/error-handling.test.ts

@@ -431,6 +431,30 @@ describe('Class: Router - Error Handling', () => {
     });
   });
 
+  it('handles returning a JSONObject from the error handler', async () => {
+    // Prepare
+    const app = new Router();
+
+    app.errorHandler(BadRequestError, async () => ({ foo: 'bar' }));
+
+    app.get('/test', () => {
+      throw new BadRequestError('test error');
+    });
+
+    // Act
+    const result = await app.resolve(createTestEvent('/test', 'GET'), context);
+
+    // Assess
+    expect(result).toEqual({
+      statusCode: HttpErrorCodes.OK,
+      body: JSON.stringify({
+        foo: 'bar',
+      }),
+      headers: { 'content-type': 'application/json' },
+      isBase64Encoded: false,
+    });
+  });
+
   it('handles throwing a built in NotFound error from the error handler', async () => {
     // Prepare
     const app = new Router();