wip: migrate from connect to polka

Migrates from connect to polka, a much lighter and faster middleware
server/router.

Marked as WIP until we figure out what to do about fallback middleware.

packages/vite/package.json

@@ -108,7 +108,7 @@
     "artichokie": "^0.2.1",
     "cac": "^6.7.14",
     "chokidar": "^3.6.0",
-    "connect": "^3.7.0",
+    "polka": "^0.5.2",
     "convert-source-map": "^2.0.0",
     "cors": "^2.8.5",
     "cross-spawn": "^7.0.3",

packages/vite/src/node/http.ts

@@ -2,8 +2,8 @@ import fsp from 'node:fs/promises'
 import path from 'node:path'
 import type { OutgoingHttpHeaders as HttpServerHeaders } from 'node:http'
 import type { ServerOptions as HttpsServerOptions } from 'node:https'
-import type { Connect } from 'dep-types/connect'
 import colors from 'picocolors'
+import type { Polka } from 'dep-types/polka'
 import type { ProxyOptions } from './server/middlewares/proxy'
 import type { Logger } from './logger'
 import type { HttpServer } from './server'
@@ -89,31 +89,26 @@ export type CorsOrigin = boolean | string | RegExp | (string | RegExp)[]
 
 export async function resolveHttpServer(
   { proxy }: CommonServerOptions,
-  app: Connect.Server,
   httpsOptions?: HttpsServerOptions,
 ): Promise<HttpServer> {
   if (!httpsOptions) {
     const { createServer } = await import('node:http')
-    return createServer(app)
+    return createServer()
   }
 
   // #484 fallback to http1 when proxy is needed.
   if (proxy) {
     const { createServer } = await import('node:https')
-    return createServer(httpsOptions, app)
+    return createServer(httpsOptions)
   } else {
     const { createSecureServer } = await import('node:http2')
-    return createSecureServer(
-      {
-        // Manually increase the session memory to prevent 502 ENHANCE_YOUR_CALM
-        // errors on large numbers of requests
-        maxSessionMemory: 1000,
-        ...httpsOptions,
-        allowHTTP1: true,
-      },
-      // @ts-expect-error TODO: is this correct?
-      app,
-    )
+    return createSecureServer({
+      // Manually increase the session memory to prevent 502 ENHANCE_YOUR_CALM
+      // errors on large numbers of requests
+      maxSessionMemory: 1000,
+      ...httpsOptions,
+      allowHTTP1: true,
+    })
   }
 }
 
@@ -140,6 +135,7 @@ async function readFileIfExists(value?: string | Buffer | any[]) {
 
 export async function httpServerStart(
   httpServer: HttpServer,
+  middlewares: Polka.Polka | undefined,
   serverOptions: {
     port: number
     strictPort: boolean | undefined
@@ -167,6 +163,10 @@ export async function httpServerStart(
 
     httpServer.on('error', onError)
 
+    if (middlewares) {
+      httpServer.on('request', middlewares.handler)
+    }
+
     httpServer.listen(port, host, () => {
       httpServer.removeListener('error', onError)
       resolve(port)

packages/vite/src/node/index.ts

@@ -167,7 +167,7 @@ export type {
   ResolverObject,
   Alias,
 } from 'dep-types/alias'
-export type { Connect } from 'dep-types/connect'
+export type { Polka } from 'dep-types/polka'
 export type { WebSocket, WebSocketAlias } from 'dep-types/ws'
 export type { HttpProxy } from 'dep-types/http-proxy'
 export type {

packages/vite/src/node/preview.ts

@@ -2,8 +2,8 @@ import fs from 'node:fs'
 import path from 'node:path'
 import sirv from 'sirv'
 import compression from '@polka/compression'
-import connect from 'connect'
-import type { Connect } from 'dep-types/connect'
+import polka from 'polka'
+import type { Polka } from 'dep-types/polka'
 import corsMiddleware from 'cors'
 import { DEFAULT_PREVIEW_PORT } from './constants'
 import type {
@@ -78,7 +78,7 @@ export interface PreviewServer {
    *
    * https://github.com/senchalabs/connect#use-middleware
    */
-  middlewares: Connect.Server
+  middlewares: Polka.Polka
   /**
    * native Node http server instance
    */
@@ -132,12 +132,11 @@ export async function preview(
     )
   }
 
-  const app = connect() as Connect.Server
   const httpServer = await resolveHttpServer(
     config.preview,
-    app,
     await resolveHttpsConfig(config.preview?.https),
   )
+  const app = polka({ server: httpServer })
   setClientErrorHandler(httpServer, config.logger)
 
   const options = config.preview
@@ -242,7 +241,7 @@ export async function preview(
   const hostname = await resolveHostname(options.host)
   const port = options.port ?? DEFAULT_PREVIEW_PORT
 
-  await httpServerStart(httpServer, {
+  await httpServerStart(httpServer, app, {
     port,
     strictPort: options.strictPort,
     host: hostname.host,

packages/vite/src/node/server/index.ts

@@ -6,12 +6,12 @@ import { get as httpsGet } from 'node:https'
 import type * as http from 'node:http'
 import { performance } from 'node:perf_hooks'
 import type { Http2SecureServer } from 'node:http2'
-import connect from 'connect'
+import polka from 'polka'
 import corsMiddleware from 'cors'
 import colors from 'picocolors'
 import chokidar from 'chokidar'
 import type { FSWatcher, WatchOptions } from 'dep-types/chokidar'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import launchEditorMiddleware from 'launch-editor-middleware'
 import type { SourceMap } from 'rollup'
 import picomatch from 'picomatch'
@@ -236,7 +236,7 @@ export interface ViteDevServer {
    *
    * https://github.com/senchalabs/connect#use-middleware
    */
-  middlewares: Connect.Server
+  middlewares: Polka.Polka
   /**
    * native Node http server instance
    * will be null in middleware mode
@@ -460,10 +460,10 @@ export async function _createServer(
     emptyOutDir,
   )
 
-  const middlewares = connect() as Connect.Server
   const httpServer = middlewareMode
     ? null
-    : await resolveHttpServer(serverConfig, middlewares, httpsOptions)
+    : await resolveHttpServer(serverConfig, httpsOptions)
+  const middlewares = polka({ server: httpServer }) as Polka.Polka
 
   const ws = createWebSocketServer(httpServer, config, httpsOptions)
   const hot = createHMRBroadcaster()
@@ -920,7 +920,7 @@ export async function _createServer(
   }
 
   // error handler
-  middlewares.use(errorMiddleware(server, !!middlewareMode))
+  middlewares.onError = errorMiddleware(server, !!middlewareMode)
 
   // httpServer.listen can be called multiple times
   // when port when using next port number
@@ -978,6 +978,7 @@ async function startServer(
   }
 
   const options = server.config.server
+  const middlewares = server.middlewares
   const hostname = await resolveHostname(options.host)
   const configPort = inlinePort ?? options.port
   // When using non strict port for the dev server, the running port can be different from the config one.
@@ -989,7 +990,7 @@ async function startServer(
       : configPort) ?? DEFAULT_DEV_PORT
   server._configServerPort = configPort
 
-  const serverPort = await httpServerStart(httpServer, {
+  const serverPort = await httpServerStart(httpServer, middlewares, {
     port,
     strictPort: options.strictPort,
     host: hostname.host,
@@ -1151,7 +1152,7 @@ async function restartServer(server: ViteDevServer) {
 
     // Keep the same connect instance so app.use(vite.middlewares) works
     // after a restart in middlewareMode (.route is always '/')
-    middlewares.stack = newServer.middlewares.stack
+    middlewares.wares = newServer.middlewares.wares
     server.middlewares = middlewares
 
     // Rebind internal server variable so functions reference the user server

packages/vite/src/node/server/middlewares/base.ts

@@ -1,4 +1,4 @@
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import { joinUrlSegments, stripBase } from '../../utils'
 import { cleanUrl, withTrailingSlash } from '../../../shared/utils'
 
@@ -7,7 +7,7 @@ import { cleanUrl, withTrailingSlash } from '../../../shared/utils'
 export function baseMiddleware(
   rawBase: string,
   middlewareMode: boolean,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function viteBaseMiddleware(req, res, next) {
     const url = req.url!

packages/vite/src/node/server/middlewares/error.ts

@@ -1,6 +1,6 @@
 import colors from 'picocolors'
 import type { RollupError } from 'rollup'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import strip from 'strip-ansi'
 import type { ErrorPayload } from 'types/hmrPayload'
 import { pad } from '../../utils'
@@ -60,7 +60,7 @@ export function logError(server: ViteDevServer, err: RollupError): void {
 export function errorMiddleware(
   server: ViteDevServer,
   allowNext = false,
-): Connect.ErrorHandleFunction {
+): Polka.ErrorHandler {
   // note the 4 args must be kept for connect to treat this as error middleware
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function viteErrorMiddleware(err: RollupError, _req, res, next) {
@@ -88,5 +88,5 @@ export function errorMiddleware(
         </html>
       `)
     }
-  }
+  } as Polka.ErrorHandler
 }

packages/vite/src/node/server/middlewares/htmlFallback.ts

@@ -1,5 +1,5 @@
 import path from 'node:path'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import { createDebugger } from '../../utils'
 import type { FsUtils } from '../../fsUtils'
 import { commonFsUtils } from '../../fsUtils'
@@ -11,7 +11,7 @@ export function htmlFallbackMiddleware(
   root: string,
   spaFallback: boolean,
   fsUtils: FsUtils = commonFsUtils,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function viteHtmlFallbackMiddleware(req, res, next) {
     if (

packages/vite/src/node/server/middlewares/indexHtml.ts

@@ -2,7 +2,7 @@ import fsp from 'node:fs/promises'
 import path from 'node:path'
 import MagicString from 'magic-string'
 import type { SourceMapInput } from 'rollup'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import type { DefaultTreeAdapterMap, Token } from 'parse5'
 import type { IndexHtmlTransformHook } from '../../plugins/html'
 import {
@@ -407,7 +407,7 @@ const devHtmlHook: IndexHtmlTransformHook = async (
 export function indexHtmlMiddleware(
   root: string,
   server: ViteDevServer | PreviewServer,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   const isDev = isDevServer(server)
   const fsUtils = getFsUtils(server.config)
 

packages/vite/src/node/server/middlewares/notFound.ts

@@ -1,6 +1,6 @@
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 
-export function notFoundMiddleware(): Connect.NextHandleFunction {
+export function notFoundMiddleware(): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function vite404Middleware(_, res) {
     res.statusCode = 404

packages/vite/src/node/server/middlewares/proxy.ts

@@ -1,7 +1,7 @@
 import type * as http from 'node:http'
 import type * as net from 'node:net'
 import httpProxy from 'http-proxy'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import type { HttpProxy } from 'dep-types/http-proxy'
 import colors from 'picocolors'
 import { createDebugger } from '../../utils'
@@ -56,7 +56,7 @@ export function proxyMiddleware(
   httpServer: HttpServer | null,
   options: NonNullable<CommonServerOptions['proxy']>,
   config: ResolvedConfig,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   // lazy require only when proxy is used
   const proxies: Record<string, [HttpProxy.Server, ProxyOptions]> = {}
 

packages/vite/src/node/server/middlewares/static.ts

@@ -2,7 +2,7 @@ import path from 'node:path'
 import type { OutgoingHttpHeaders, ServerResponse } from 'node:http'
 import type { Options } from 'sirv'
 import sirv from 'sirv'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import escapeHtml from 'escape-html'
 import type { ViteDevServer } from '../..'
 import { FS_PREFIX } from '../../constants'
@@ -57,7 +57,7 @@ const sirvOptions = ({
 export function servePublicMiddleware(
   server: ViteDevServer,
   publicFiles?: Set<string>,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   const dir = server.config.publicDir
   const serve = sirv(
     dir,
@@ -96,7 +96,7 @@ export function servePublicMiddleware(
 
 export function serveStaticMiddleware(
   server: ViteDevServer,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   const dir = server.config.root
   const serve = sirv(
     dir,
@@ -165,7 +165,7 @@ export function serveStaticMiddleware(
 
 export function serveRawFsMiddleware(
   server: ViteDevServer,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   const serveFromRoot = sirv(
     '/',
     sirvOptions({ getHeaders: () => server.config.server.headers }),
@@ -233,7 +233,7 @@ function ensureServingAccess(
   url: string,
   server: ViteDevServer,
   res: ServerResponse,
-  next: Connect.NextFunction,
+  next: Polka.Next,
 ): boolean {
   if (isFileServingAllowed(url, server)) {
     return true

packages/vite/src/node/server/middlewares/time.ts

@@ -1,10 +1,10 @@
 import { performance } from 'node:perf_hooks'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import { createDebugger, prettifyUrl, timeFrom } from '../../utils'
 
 const logTime = createDebugger('vite:time')
 
-export function timeMiddleware(root: string): Connect.NextHandleFunction {
+export function timeMiddleware(root: string): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function viteTimeMiddleware(req, res, next) {
     const start = performance.now()

packages/vite/src/node/server/middlewares/transform.ts

@@ -1,6 +1,6 @@
 import path from 'node:path'
 import fsp from 'node:fs/promises'
-import type { Connect } from 'dep-types/connect'
+import type { Polka } from 'dep-types/polka'
 import colors from 'picocolors'
 import type { ExistingRawSourceMap } from 'rollup'
 import type { ViteDevServer } from '..'
@@ -45,7 +45,7 @@ const knownIgnoreList = new Set(['/', '/favicon.ico'])
  */
 export function cachedTransformMiddleware(
   server: ViteDevServer,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
   return function viteCachedTransformMiddleware(req, res, next) {
     // check if we can return 304 early
@@ -71,7 +71,7 @@ export function cachedTransformMiddleware(
 
 export function transformMiddleware(
   server: ViteDevServer,
-): Connect.NextHandleFunction {
+): Polka.RequestHandler {
   // Keep the named function. The name is visible in debug logs via `DEBUG=connect:dispatcher ...`
 
   // check if public dir is inside root dir