vite preview proxy config read null

[hehehai]

Describe the bug

script: $ vite preview --config ./vite.config.preview.ts

config file port

export default defineConfig({
  mode: 'development',
  preview: {
    host: '0.0.0.0',
    port: 4173,
    strictPort: true,
    open: true,
    proxy: {
      '/api': {
        target: 'http://localhost',
        changeOrigin: true,
        rewrite: (path) => path.replace(/^\/api/, '/'),
      },
    },
  },
  ......
});

Problem location

TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at proxyMiddleware (/Users/guanwei/code/company/cbj_pro/cbj_app/node_modules/.pnpm/registry.npmmirror.com+vite@2.7.10_less@4.1.2/node_modules/vite/dist/node/chunks/dep-76613303.js:50062:12)
    at Object.preview (/Users/guanwei/code/company/cbj_pro/cbj_app/node_modules/.pnpm/registry.npmmirror.com+vite@2.7.10_less@4.1.2/node_modules/vite/dist/node/chunks/dep-76613303.js:73391:17)

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

Lines 81 to 83 in 870e1c0

	if (config.preview.proxy) {
	app.use(proxyMiddleware(httpServer, config))
	}

Local dependency code

async function preview(inlineConfig) {
	......
	// proxy
    if (config.preview.proxy) {
        app.use(proxyMiddleware(httpServer, config));
    }
	......
}

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

Lines 31 to 40 in 870e1c0

	export function proxyMiddleware(
	httpServer: http.Server | null,
	config: ResolvedConfig
	): Connect.NextHandleFunction {
	const options = config.server.proxy!
	// lazy require only when proxy is used
	const proxies: Record<string, [HttpProxy.Server, ProxyOptions]> = {}
	Object.keys(options).forEach((context) => {

Local dependency code

function proxyMiddleware(httpServer, config) {
	const options = config.server.proxy;
    // lazy require only when proxy is used
    const proxies = {};
    Object.keys(options) ......
}

Judge is config.preview.proxy, but read is config.server.proxy

Reproduction

System Info

System:
    OS: macOS 12.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 5.07 GB / 32.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.17.3 - /usr/local/bin/node
    Yarn: 1.22.17 - ~/.yarn/bin/yarn
    npm: 7.24.0 - /usr/local/bin/npm
    Watchman: 2021.11.01.00 - /usr/local/bin/watchman
  Browsers:
    Chrome: 97.0.4692.99
    Firefox: 95.0.2
    Safari: 15.2
  npmPackages:
    @vitejs/plugin-vue: ^1.9.4 => 1.10.2 
    @vitejs/plugin-vue-jsx: ^1.2.0 => 1.3.3 
    vite: ^2.6.4 => 2.7.10

Used Package Manager

pnpm

Logs

❯ pnpm build
.....
success

❯ pnpm preview

> arco-design-pro-vue@1.0.0 preview /Users/guanwei/code/company/cbj_pro/cbj_app
> vite preview --config ./config/vite.config.preview.ts

error when starting preview server:
TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at proxyMiddleware (/Users/guanwei/code/company/cbj_pro/cbj_app/node_modules/.pnpm/registry.npmmirror.com+vite@2.7.10_less@4.1.2/node_modules/vite/dist/node/chunks/dep-76613303.js:50062:12)
    at Object.preview (/Users/guanwei/code/company/cbj_pro/cbj_app/node_modules/.pnpm/registry.npmmirror.com+vite@2.7.10_less@4.1.2/node_modules/vite/dist/node/chunks/dep-76613303.js:73391:17)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)
    at async CAC.<anonymous> (/Users/guanwei/code/company/cbj_pro/cbj_app/node_modules/.pnpm/registry.npmmirror.com+vite@2.7.10_less@4.1.2/node_modules/vite/dist/node/cli.js:782:24)
 ELIFECYCLE  Command failed with exit code 1.

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/vue-next instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[bluwy]

This is the same as #7414 and is fixed in #7604. Also credits to #6666 which had implemented the same fix but we had missed out on merging it.