.eslintrc.cjs

@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ['@hono/eslint-config'],
+}

.vscode/settings.json

@@ -0,0 +1,11 @@
+{
+  "eslint.validate": [
+    "javascript",
+    "javascriptreact",
+    "typescript",
+    "typescriptreact"
+  ],
+  "editor.codeActionsOnSave": {
+    "source.fixAll.eslint": "explicit"
+  }
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@hono/node-server",
-  "version": "1.3.3",
+  "version": "1.3.4",
   "description": "Node.js Adapter for Hono",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -43,7 +43,9 @@
     "watch": "tsup --watch",
     "postbuild": "publint",
     "prerelease": "yarn build && yarn test",
-    "release": "np"
+    "release": "np",
+    "lint": "eslint --ext js,ts src test",
+    "lint:fix": "eslint --ext js,ts src test --fix"
   },
   "license": "MIT",
   "repository": {
@@ -60,10 +62,12 @@
     "node": ">=18.14.1"
   },
   "devDependencies": {
+    "@hono/eslint-config": "^0.0.2",
     "@types/jest": "^29.5.3",
     "@types/node": "^20.10.0",
     "@types/supertest": "^2.0.12",
-    "hono": "^3.9.2",
+    "eslint": "^8.55.0",
+    "hono": "^3.11.7",
     "jest": "^29.6.1",
     "np": "^7.7.0",
     "publint": "^0.1.16",

src/listener.ts

@@ -1,10 +1,10 @@
 import type { IncomingMessage, ServerResponse, OutgoingHttpHeaders } from 'node:http'
 import type { Http2ServerRequest, Http2ServerResponse } from 'node:http2'
-import type { FetchCallback } from './types'
-import './globals'
-import { cacheKey } from './response'
 import { newRequest } from './request'
+import { cacheKey } from './response'
+import type { FetchCallback } from './types'
 import { writeFromReadableStream, buildOutgoingHttpHeaders } from './utils'
+import './globals'
 
 const regBuffer = /^no$/i
 const regContentType = /^(application\/json\b|text\/(?!event-stream\b))/i
@@ -25,6 +25,8 @@ const handleResponseError = (e: unknown, outgoing: ServerResponse | Http2ServerR
     console.info('The user aborted a request.')
   } else {
     console.error(e)
+    if (!outgoing.headersSent) outgoing.writeHead(500, { 'Content-Type': 'text/plain' })
+    outgoing.end(`Error: ${err.message}`)
     outgoing.destroy(err)
   }
 }
@@ -33,6 +35,7 @@ const responseViaCache = (
   res: Response,
   outgoing: ServerResponse | Http2ServerResponse
 ): undefined | Promise<undefined> => {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const [status, body, header] = (res as any)[cacheKey]
   if (typeof body === 'string') {
     header['Content-Length'] = Buffer.byteLength(body)
@@ -53,6 +56,13 @@ const responseViaResponseObject = async (
   if (res instanceof Promise) {
     res = await res.catch(handleFetchError)
   }
+  if (!(res instanceof Response)) {
+    return handleResponseError(
+      // @ts-expect-error the object must have `toString()`
+      new Error(`The response is not an instance of Response, but ${res.toString()}`),
+      outgoing
+    )
+  }
   if (cacheKey in res) {
     try {
       return responseViaCache(res as Response, outgoing)

src/request.ts

@@ -1,8 +1,9 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 // Define prototype for lightweight pseudo Request object
 
-import { Readable } from 'node:stream'
 import type { IncomingMessage } from 'node:http'
 import type { Http2ServerRequest } from 'node:http2'
+import { Readable } from 'node:stream'
 
 const newRequestFromIncoming = (
   method: string,
@@ -80,4 +81,4 @@ export const newRequest = (incoming: IncomingMessage | Http2ServerRequest) => {
   const req = Object.create(requestPrototype)
   req[incomingKey] = incoming
   return req
-};
+}

src/response.ts

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 // Define lightweight pseudo Response class and replace global.Response with it.
 
 import type { OutgoingHttpHeaders } from 'node:http'

src/serve-static.ts

@@ -1,5 +1,6 @@
+import type { ReadStream} from 'fs'
+import { createReadStream, existsSync, lstatSync } from 'fs'
 import type { MiddlewareHandler } from 'hono'
-import { ReadStream, createReadStream, existsSync, lstatSync } from 'fs'
 import { getFilePath } from 'hono/utils/filepath'
 import { getMimeType } from 'hono/utils/mime'
 

src/server.ts

@@ -1,12 +1,13 @@
 import { createServer as createServerHTTP } from 'node:http'
 import type { AddressInfo } from 'node:net'
-import type { Options, ServerType } from './types'
 import { getRequestListener } from './listener'
+import type { Options, ServerType } from './types'
 
 export const createAdaptorServer = (options: Options): ServerType => {
   const fetchCallback = options.fetch
   const requestListener = getRequestListener(fetchCallback)
   // ts will complain about createServerHTTP and createServerHTTP2 not being callable, which works just fine
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const createServer: any = options.createServer || createServerHTTP
   const server: ServerType = createServer(options.serverOptions || {}, requestListener)
   return server

src/types.ts

@@ -1,8 +1,4 @@
 import type { createServer, Server, ServerOptions as HttpServerOptions } from 'node:http'
-import type {
-  createServer as createHttpsServer,
-  ServerOptions as HttpsServerOptions,
-} from 'node:https'
 import type {
   createSecureServer as createSecureHttp2Server,
   createServer as createHttp2Server,
@@ -11,6 +7,10 @@ import type {
   SecureServerOptions as SecureHttp2ServerOptions,
   ServerOptions as Http2ServerOptions,
 } from 'node:http2'
+import type {
+  createServer as createHttpsServer,
+  ServerOptions as HttpsServerOptions,
+} from 'node:https'
 
 export type FetchCallback = (request: Request) => Promise<unknown> | unknown
 

src/utils.ts

@@ -1,11 +1,11 @@
-import type { Writable } from 'node:stream'
 import type { OutgoingHttpHeaders } from 'node:http'
+import type { Writable } from 'node:stream'
 
 export function writeFromReadableStream(stream: ReadableStream<Uint8Array>, writable: Writable) {
   if (stream.locked) {
     throw new TypeError('ReadableStream is locked.')
   } else if (writable.destroyed) {
-    stream.cancel();
+    stream.cancel()
     return
   }
   const reader = stream.getReader()
@@ -16,6 +16,7 @@ export function writeFromReadableStream(stream: ReadableStream<Uint8Array>, writ
     writable.off('close', cancel)
     writable.off('error', cancel)
   })
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   function cancel(error?: any) {
     reader.cancel(error).catch(() => {})
     if (error) writable.destroy(error)
@@ -28,7 +29,7 @@ export function writeFromReadableStream(stream: ReadableStream<Uint8Array>, writ
       if (done) {
         writable.end()
       } else if (!writable.write(value)) {
-        writable.once("drain", onDrain);
+        writable.once('drain', onDrain)
       } else {
         return reader.read().then(flow, cancel)
       }

src/vercel.ts

@@ -1,6 +1,7 @@
 import type { Hono } from 'hono'
 import { getRequestListener } from './listener'
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export const handle = (app: Hono<any, any, any>) => {
   return getRequestListener(app.fetch)
 }

test/request.test.ts

@@ -1,4 +1,4 @@
-import { IncomingMessage } from 'node:http'
+import type { IncomingMessage } from 'node:http'
 import { newRequest } from '../src/request'
 
 describe('Request', () => {

test/response.test.ts

@@ -1,5 +1,5 @@
 import { createServer, type Server } from 'node:http'
-import { AddressInfo } from 'node:net'
+import type { AddressInfo } from 'node:net'
 import { GlobalResponse } from '../src/response'
 
 class NextResponse extends Response {}
@@ -56,6 +56,7 @@ describe('Response', () => {
 
     // can only use new operator
     expect(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
       ;(Response as any)()
     }).toThrow()
 

test/serve-static.test.ts

@@ -1,7 +1,7 @@
-import { createAdaptorServer } from './../src/server'
 import { Hono } from 'hono'
 import request from 'supertest'
 import { serveStatic } from './../src/serve-static'
+import { createAdaptorServer } from './../src/server'
 
 describe('Serve Static Middleware', () => {
   const app = new Hono()
@@ -59,7 +59,7 @@ describe('Serve Static Middleware', () => {
   it('Should return 404 for non-existent files', async () => {
     const res = await request(server).get('/static/does-not-exist.html')
     expect(res.status).toBe(404)
-    expect(res.headers['content-type']).toBe('text/plain;charset=UTF-8')
+    expect(res.headers['content-type']).toBe('text/plain; charset=UTF-8')
     expect(res.text).toBe('404 Not Found')
   })
 

test/server.test.ts

@@ -1,12 +1,12 @@
-import { createAdaptorServer } from '../src/server'
-import request from 'supertest'
+import fs from 'node:fs'
+import { createServer as createHttp2Server } from 'node:http2'
+import { createServer as createHTTPSServer } from 'node:https'
 import { Hono } from 'hono'
+import { basicAuth } from 'hono/basic-auth'
 import { compress } from 'hono/compress'
 import { poweredBy } from 'hono/powered-by'
-import { basicAuth } from 'hono/basic-auth'
-import { createServer as createHTTPSServer } from 'node:https'
-import { createServer as createHttp2Server } from 'node:http2'
-import fs from 'node:fs'
+import request from 'supertest'
+import { createAdaptorServer } from '../src/server'
 
 describe('Basic', () => {
   const app = new Hono()
@@ -24,6 +24,10 @@ describe('Basic', () => {
   app.delete('/posts/:id', (c) => {
     return c.text(`DELETE ${c.req.param('id')}`)
   })
+  // @ts-expect-error the response is string
+  app.get('/invalid', () => {
+    return '<h1>HTML</h1>'
+  })
 
   const server = createAdaptorServer(app)
 
@@ -56,7 +60,15 @@ describe('Basic', () => {
   it('Should return 201 response - DELETE /posts/123', async () => {
     const res = await request(server).delete('/posts/123')
     expect(res.status).toBe(200)
-    expect(res.text).toBe(`DELETE 123`)
+    expect(res.text).toBe('DELETE 123')
+  })
+
+  it('Should return 500 response - GET /invalid', async () => {
+    const res = await request(server).get('/invalid')
+    expect(res.status).toBe(500)
+    expect(res.headers['content-type']).toBe('text/plain')
+    // The error message might be changed.
+    expect(res.text).toBe('Error: The response is not an instance of Response, but <h1>HTML</h1>')
   })
 })
 
@@ -77,15 +89,15 @@ describe('Routing', () => {
     it('Should return responses from `/book/*`', async () => {
       let res = await request(server).get('/book')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`get /book`)
+      expect(res.text).toBe('get /book')
 
       res = await request(server).get('/book/123')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`get /book/123`)
+      expect(res.text).toBe('get /book/123')
 
       res = await request(server).post('/book')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`post /book`)
+      expect(res.text).toBe('post /book')
     })
   })
 
@@ -106,11 +118,11 @@ describe('Routing', () => {
     it('Should return responses from `/chained/*`', async () => {
       let res = await request(server).get('/chained/abc')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`GET for abc`)
+      expect(res.text).toBe('GET for abc')
 
       res = await request(server).post('/chained/abc')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`POST for abc`)
+      expect(res.text).toBe('POST for abc')
 
       res = await request(server).put('/chained/abc')
       expect(res.status).toBe(404)
@@ -478,7 +490,6 @@ describe('Hono compression', () => {
   })
 })
 
-
 describe('set child response to c.res', () => {
   const app = new Hono()
   app.use('*', async (c, next) => {
@@ -497,4 +508,4 @@ describe('set child response to c.res', () => {
     expect(res.status).toBe(200)
     expect(res.headers['content-type']).toMatch(/application\/json/)
   })
-})
+})

test/vercel.test.ts

@@ -1,5 +1,5 @@
-import request from 'supertest'
 import { Hono } from 'hono'
+import request from 'supertest'
 import { handle } from '../src/vercel'
 
 describe('Basic', () => {
@@ -40,7 +40,7 @@ describe('Basic', () => {
   it('Should return 201 response - DELETE /api/posts/123', async () => {
     const res = await request(server).delete('/api/posts/123')
     expect(res.status).toBe(200)
-    expect(res.text).toBe(`DELETE 123`)
+    expect(res.text).toBe('DELETE 123')
   })
 })
 
@@ -63,15 +63,15 @@ describe('Routing', () => {
     it('Should return responses from `/v2/api/*`', async () => {
       let res = await request(server).get('/v2/api')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`get /api`)
+      expect(res.text).toBe('get /api')
 
       res = await request(server).get('/v2/api/123')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`get /api/123`)
+      expect(res.text).toBe('get /api/123')
 
       res = await request(server).post('/v2/api')
       expect(res.status).toBe(200)
-      expect(res.text).toBe(`post /api`)
+      expect(res.text).toBe('post /api')
     })
   })
 })