fix: respect cors and proxy options in preview command

close #2279

packages/vite/src/node/cli.ts

@@ -4,7 +4,7 @@ import { BuildOptions } from './build'
 import { ServerOptions } from './server'
 import { createLogger, LogLevel } from './logger'
 import { resolveConfig } from '.'
-import { serve } from './serve'
+import { preview } from './preview'
 
 const cli = cac('vite')
 
@@ -206,7 +206,7 @@ cli
           'serve',
           'development'
         )
-        await serve(config, options.port)
+        await preview(config, options.port)
       } catch (e) {
         createLogger(options.logLevel).error(
           chalk.red(`error when starting preview server:\n${e.stack}`)

packages/vite/src/node/serve.ts → packages/vite/src/node/preview.ts

@@ -8,9 +8,23 @@ import { ResolvedConfig } from '.'
 import { Connect } from 'types/connect'
 import { resolveHttpServer } from './server/http'
 import { openBrowser } from './server/openBrowser'
+import corsMiddleware from 'cors'
+import { proxyMiddleware } from './server/middlewares/proxy'
 
-export async function serve(config: ResolvedConfig, port = 5000) {
+export async function preview(config: ResolvedConfig, port = 5000) {
   const app = connect() as Connect.Server
+  const httpServer = await resolveHttpServer(config.server, app)
+
+  // cors
+  const { cors } = config.server
+  if (cors !== false) {
+    app.use(corsMiddleware(typeof cors === 'boolean' ? {} : cors))
+  }
+
+  // proxy
+  if (config.server.proxy) {
+    app.use(proxyMiddleware(httpServer, config))
+  }
 
   app.use(compression())
 
@@ -23,15 +37,13 @@ export async function serve(config: ResolvedConfig, port = 5000) {
     })
   )
 
-  const server = await resolveHttpServer(config.server, app)
-
   const options = config.server || {}
   const hostname = options.host || 'localhost'
   const protocol = options.https ? 'https' : 'http'
   const logger = config.logger
   const base = config.base
 
-  server.listen(port, () => {
+  httpServer.listen(port, () => {
     logger.info(
       chalk.cyan(`\n  vite v${require('vite/package.json').version}`) +
         chalk.green(` build preview server running at:\n`)

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

@@ -403,7 +403,7 @@ export async function createServer(
   // proxy
   const { proxy } = serverConfig
   if (proxy) {
-    middlewares.use(proxyMiddleware(server))
+    middlewares.use(proxyMiddleware(httpServer, config))
   }
 
   // base

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

@@ -2,10 +2,10 @@ import * as http from 'http'
 import { createDebugger } from '../../utils'
 import httpProxy from 'http-proxy'
 import { HMR_HEADER } from '../ws'
-import { ViteDevServer } from '..'
 import { Connect } from 'types/connect'
 import { HttpProxy } from 'types/http-proxy'
 import chalk from 'chalk'
+import { ResolvedConfig } from '../..'
 
 const debug = createDebugger('vite:proxy')
 
@@ -28,10 +28,10 @@ export interface ProxyOptions extends HttpProxy.ServerOptions {
   ) => void | null | undefined | false | string
 }
 
-export function proxyMiddleware({
-  httpServer,
-  config
-}: ViteDevServer): Connect.NextHandleFunction {
+export function proxyMiddleware(
+  httpServer: http.Server | null,
+  config: ResolvedConfig
+): Connect.NextHandleFunction {
   const options = config.server.proxy!
 
   // lazy require only when proxy is used