fix: handle errors in non-async handlers

package.json

@@ -1,6 +1,6 @@
 {
   "name": "crosswalk",
-  "version": "2.2.4",
+  "version": "2.2.5",
   "description": "Type-safe express routing with TypeScript",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/__tests__/typed-router.test.ts

@@ -491,7 +491,7 @@ test('Throwing HTTPError should set status code', async () => {
       name: 'John',
       age: 34,
       phoneNumbers: [],
-      role: 'user',
+      role: 'user' as const,
       permanentAddress: {
         street: '123 Main St',
         city: 'Anytown',
@@ -525,6 +525,67 @@ test('Throwing HTTPError should set status code', async () => {
   expect(r.body).toEqual({});
 });
 
+test('Throwing HTTPError should set status code in non-async handlers', async () => {
+  const app = express();
+  const router = new TypedRouter<API>(app, apiSchemaJson);
+
+  class PGError extends Error {
+    constructor(public code: string) {
+      super();
+    }
+  }
+
+  router.get('/users', async () => {
+    return {users: [] as User[]};
+  });
+
+  router.get('/users/:userId', ({userId}) => {
+    if (userId === 'throw-400') {
+      throw new HTTPError(400, 'Very bad request');
+    } else if (userId === 'throw-pg-error') {
+      // See https://github.com/danvk/crosswalk/issues/6
+      throw new PGError('23505');
+    }
+
+    return Promise.resolve({
+      id: '1',
+      name: 'John',
+      age: 34,
+      phoneNumbers: [],
+      role: 'user' as const,
+      permanentAddress: {
+        street: '123 Main St',
+        city: 'Anytown',
+        state: 'CA',
+        zip: '12345',
+        location: {
+          latitude: 37.774929,
+          longitude: -122.419416,
+        },
+      },
+    });
+  });
+
+  const api = request(app);
+  let r = await api.get('/users/fred').expect(200);
+  expect(r.body).toMatchObject({
+    name: 'John',
+    age: 34,
+  });
+
+  r = await api.get('/users?minAge=Fred').expect(400);
+  expect(r.body).toMatchObject({error: 'data/minAge must be number'});
+
+  r = await api.get('/users?maxAge=5').expect(400);
+  expect(r.body).toMatchObject({error: 'data must NOT have additional properties'});
+
+  r = await api.get('/users/throw-400').expect(400);
+  expect(r.body).toMatchObject({error: 'Very bad request'});
+
+  r = await api.get('/users/throw-pg-error').expect(500);
+  expect(r.body).toEqual({});
+});
+
 test('Custom 400 handler', async () => {
   const app = express();
   const router = new TypedRouter<API>(app, apiSchemaJson, {

src/typed-router.ts

@@ -153,7 +153,7 @@ export class TypedRouter<API> {
     const queryValidate = this.getValidator(route, method, 'query');
     this.registrations.push({path: route as string, method});
 
-    let handlerFn = (...[req, response, next]: RequestParams) => {
+    let handlerFn = async (...[req, response, next]: RequestParams) => {
       const {body, query} = req;
 
       if (bodyValidate && !bodyValidate(body)) {
@@ -183,33 +183,33 @@ export class TypedRouter<API> {
         console.debug(method, route, 'params=', req.params, 'body=', body, 'query=', query);
       }
 
-      handler(req.params as any, body, req as any, response)
-        .then(responseObject => {
-          if (responseObject === null) {
-            // nothing to do. This can happen if the response redirected, say.
-          } else if (typeof responseObject === 'string') {
-            response.status(200).send(responseObject);
-          } else {
-            response.json(responseObject);
-          }
-        })
-        .catch((error: any) => {
-          // With target below ES2015, instanceof doesn't work here.
-          if (
-            error instanceof HTTPError ||
-            (error.code && STATUS_CODES.indexOf(error.code) >= 0)
-          ) {
-            response.status(error.code).json({error: error.message});
-          } else {
-            next(error);
-          }
-        });
+      try {
+        const responseObject = await handler(req.params as any, body, req as any, response);
+
+        if (responseObject === null) {
+          // nothing to do. This can happen if the response redirected, say.
+        } else if (typeof responseObject === 'string') {
+          response.status(200).send(responseObject);
+        } else {
+          response.json(responseObject);
+        }
+      } catch (error: any) {
+        // Handle synchronous throws
+        if (
+          error instanceof HTTPError ||
+          (error.code && STATUS_CODES.indexOf(error.code) >= 0)
+        ) {
+          response.status(error.code).json({error: error.message});
+        } else {
+          next(error);
+        }
+      }
     };
 
     for (let i = this.middlewareFns.length - 1; i >= 0; i--) {
       const middlewareFn = this.middlewareFns[i];
       const prevHandlerFn = handlerFn;
-      handlerFn = (req: any, res: any, next: any) =>
+      handlerFn = async (req: any, res: any, next: any) =>
         middlewareFn(req, res, () => prevHandlerFn(req, res, next));
     }