feat(hono-base): skip import HTTPException by using HTTPResponseError (…

…#2898)

This change is intended to make error handling more flexible and reduce bundle size.
This idea is originated from #2885

Co-authored-by: Yusuke Wada <[email protected]>

src/hono-base.ts

@@ -7,7 +7,6 @@
 import { compose } from './compose'
 import { Context } from './context'
 import type { ExecutionContext } from './context'
-import { HTTPException } from './http-exception'
 import { HonoRequest } from './request'
 import type { Router } from './router'
 import { METHODS, METHOD_NAME_ALL, METHOD_NAME_ALL_LOWERCASE } from './router'
@@ -16,6 +15,7 @@ import type {
   ErrorHandler,
   FetchEventLike,
   H,
+  HTTPResponseError,
   HandlerInterface,
   MergePath,
   MergeSchemaPath,
@@ -38,8 +38,8 @@ const notFoundHandler = (c: Context) => {
   return c.text('404 Not Found', 404)
 }
 
-const errorHandler = (err: Error, c: Context) => {
-  if (err instanceof HTTPException) {
+const errorHandler = (err: Error | HTTPResponseError, c: Context) => {
+  if ('getResponse' in err) {
     return err.getResponse()
   }
   console.error(err)

src/hono.test.ts

@@ -1479,6 +1479,26 @@ describe('Error handle', () => {
       expect(await res.text()).toBe('Custom Error Message')
     })
   })
+
+  describe('Handle HTTPException like object', () => {
+    const app = new Hono()
+
+    class CustomError extends Error {
+      getResponse() {
+        return new Response('Custom Error', { status: 400 })
+      }
+    }
+
+    app.get('/exception', () => {
+      throw new CustomError()
+    })
+
+    it('Should return 401 response', async () => {
+      const res = await app.request('http://localhost/exception')
+      expect(res.status).toBe(400)
+      expect(await res.text()).toBe('Custom Error')
+    })
+  })
 })
 
 describe('Error handling in middleware', () => {

src/types.ts

@@ -91,8 +91,12 @@ export type H<
 > = Handler<E, P, I, R> | MiddlewareHandler<E, P, I>
 
 export type NotFoundHandler<E extends Env = any> = (c: Context<E>) => Response | Promise<Response>
+
+export interface HTTPResponseError extends Error {
+  getResponse: () => Response
+}
 export type ErrorHandler<E extends Env = any> = (
-  err: Error,
+  err: Error | HTTPResponseError,
   c: Context<E>
 ) => Response | Promise<Response>