feat: support base option during dev

docs/config/index.md

@@ -98,6 +98,13 @@ export default ({ command, mode }) => {
 
   See [Project Root](/guide/#project-root) for more details.
 
+### base
+
+- **Type:** `string`
+- **Default:** `/`
+
+  Base public path when served in development or production. Note the path should start and end with `/`. See [Public Base Path](/guide/build#public-base-path) for more details.
+
 ### mode
 
 - **Type:** `string`
@@ -322,13 +329,6 @@ export default ({ command, mode }) => {
 
 ## Build Options
 
-### build.base
-
-- **Type:** `string`
-- **Default:** `/`
-
-  Base public path when served in production. Note the path should start and end with `/`. See [Public Base Path](/guide/build#public-base-path) for more details.
-
 ### build.target
 
 - **Type:** `string`

docs/guide/build.md

@@ -23,7 +23,7 @@ Legacy browsers can be supported via [@vitejs/plugin-legacy](https://github.com/
 
 - Related: [Asset Handling](./features#asset-handling)
 
-If you are deploying your project under a nested public path, simply specify the [`build.base` config option](/config/#build-base) and all asset paths will be rewritten accordingly. This option can also be specified as a command line flag, e.g. `vite build --base=/my/public/path/`.
+If you are deploying your project under a nested public path, simply specify the [`base` config option](/config/#base) and all asset paths will be rewritten accordingly. This option can also be specified as a command line flag, e.g. `vite build --base=/my/public/path/`.
 
 JS-imported asset URLs, CSS `url()` references, and asset references in your `.html` files are all automatically adjusted to respect this option during build.
 

docs/guide/env-and-mode.md

@@ -6,7 +6,7 @@ Vite exposes env variables on the special **`import.meta.env`** object. Some bui
 
 - **`import.meta.env.MODE`**: {string} the [mode](#modes) the app is running in.
 
-- **`import.meta.env.BASE_URL`**: {string} the base url the app is being served from. In development, this is always `/`. In production, this is determined by the [`build.base` config option](/config/#build-base).
+- **`import.meta.env.BASE_URL`**: {string} the base url the app is being served from. This is determined by the [`base` config option](/config/#base).
 
 - **`import.meta.env.PROD`**: {boolean} whether the app is running in production.
 

packages/playground/assets/__tests__/assets.spec.ts

@@ -10,16 +10,40 @@ import {
 
 const assetMatch = isBuild
   ? /\/foo\/assets\/asset\.\w{8}\.png/
-  : '/nested/asset.png'
+  : '/foo/nested/asset.png'
 
-const iconMatch = isBuild ? `/foo/icon.png` : `icon.png`
+const iconMatch = `/foo/icon.png`
 
 test('should have no 404s', () => {
   browserLogs.forEach((msg) => {
     expect(msg).not.toMatch('404')
   })
 })
 
+describe('injected scripts', () => {
+  test('@vite/client', async () => {
+    const hasClient = await page.$(
+      'script[type="module"][src="/foo/@vite/client"]'
+    )
+    if (isBuild) {
+      expect(hasClient).toBeFalsy()
+    } else {
+      expect(hasClient).toBeTruthy()
+    }
+  })
+
+  test('html-proxy', async () => {
+    const hasHtmlProxy = await page.$(
+      'script[type="module"][src="/foo/index.html?html-proxy&index=0.js"]'
+    )
+    if (isBuild) {
+      expect(hasHtmlProxy).toBeFalsy()
+    } else {
+      expect(hasHtmlProxy).toBeTruthy()
+    }
+  })
+})
+
 describe('raw references from /public', () => {
   test('load raw js from /public', async () => {
     expect(await page.textContent('.raw-js')).toMatch('[success]')
@@ -70,7 +94,7 @@ describe('css url() references', () => {
   })
 
   test('base64 inline', async () => {
-    const match = isBuild ? `data:image/png;base64` : `/icon.png`
+    const match = isBuild ? `data:image/png;base64` : `/foo/nested/icon.png`
     expect(await getBg('.css-url-base64-inline')).toMatch(match)
     expect(await getBg('.css-url-quotes-base64-inline')).toMatch(match)
   })

packages/playground/assets/vite.config.js

@@ -2,8 +2,8 @@
  * @type {import('vite').UserConfig}
  */
 module.exports = {
+  base: '/foo/',
   build: {
-    base: '/foo/',
     outDir: 'dist/foo'
   }
 }

packages/plugin-legacy/index.js

@@ -265,7 +265,7 @@ function viteLegacyPlugin(options = {}) {
           tag: 'script',
           attrs: {
             type: 'module',
-            src: `${config.build.base}${modernPolyfillFilename}`
+            src: `${config.base}${modernPolyfillFilename}`
           }
         })
       } else if (modernPolyfills.size) {
@@ -295,7 +295,7 @@ function viteLegacyPlugin(options = {}) {
           tag: 'script',
           attrs: {
             nomodule: true,
-            src: `${config.build.base}${legacyPolyfillFilename}`
+            src: `${config.base}${legacyPolyfillFilename}`
           },
           injectTo: 'body'
         })
@@ -318,7 +318,7 @@ function viteLegacyPlugin(options = {}) {
             // script content will stay consistent - which allows using a constant
             // hash value for CSP.
             id: legacyEntryId,
-            'data-src': config.build.base + legacyEntryFilename
+            'data-src': config.base + legacyEntryFilename
           },
           children: systemJSInlineCode,
           injectTo: 'body'

packages/plugin-vue/src/template.ts

@@ -108,7 +108,9 @@ export function resolveTemplateCompilerOptions(
     // request
     if (filename.startsWith(options.root)) {
       assetUrlOptions = {
-        base: '/' + slash(path.relative(options.root, path.dirname(filename)))
+        base:
+          options.devServer.config.base +
+          slash(path.relative(options.root, path.dirname(filename)))
       }
     }
   } else {

packages/vite/src/client/client.ts

@@ -3,6 +3,7 @@ import { ErrorOverlay, overlayId } from './overlay'
 
 // injected by the hmr plugin when served
 declare const __ROOT__: string
+declare const __BASE__: string
 declare const __MODE__: string
 declare const __DEFINES__: Record<string, any>
 declare const __HMR_PROTOCOL__: string
@@ -38,6 +39,8 @@ const socketProtocol =
   __HMR_PROTOCOL__ || (location.protocol === 'https:' ? 'wss' : 'ws')
 const socketHost = `${__HMR_HOSTNAME__ || location.hostname}:${__HMR_PORT__}`
 const socket = new WebSocket(`${socketProtocol}://${socketHost}`, 'vite-hmr')
+const base = __BASE__ || '/'
+const baseNoSlash = base.replace(/\/$/, '')
 
 function warnFailedFetch(err: Error, path: string | string[]) {
   if (!err.message.match('fetch')) {
@@ -107,9 +110,10 @@ async function handleMessage(payload: HMRPayload) {
         // if html file is edited, only reload the page if the browser is
         // currently on that page.
         const pagePath = location.pathname
+        const payloadPath = baseNoSlash + payload.path
         if (
-          pagePath === payload.path ||
-          (pagePath.endsWith('/') && pagePath + 'index.html' === payload.path)
+          pagePath === payloadPath ||
+          (pagePath.endsWith('/') && pagePath + 'index.html' === payloadPath)
         ) {
           location.reload()
         }
@@ -259,6 +263,9 @@ export function removeStyle(id: string) {
 }
 
 async function fetchUpdate({ path, acceptedPath, timestamp }: Update) {
+  path = baseNoSlash + path
+  acceptedPath = baseNoSlash + acceptedPath
+
   const mod = hotModulesMap.get(path)
   if (!mod) {
     // In a code-splitting project,

packages/vite/src/node/build.ts

@@ -34,7 +34,7 @@ import { ssrManifestPlugin } from './ssr/ssrManifestPlugin'
 export interface BuildOptions {
   /**
    * Base public path when served in production.
-   * @default '/'
+   * @deprecated `base` is now a root-level config option.
    */
   base?: string
   /**
@@ -168,11 +168,10 @@ export interface LibraryOptions {
 
 export type LibraryFormats = 'es' | 'cjs' | 'umd' | 'iife'
 
-export function resolveBuildOptions(
-  raw?: BuildOptions
-): Required<BuildOptions> {
-  const resolved: Required<BuildOptions> = {
-    base: '/',
+export type ResolvedBuildOptions = Required<Omit<BuildOptions, 'base'>>
+
+export function resolveBuildOptions(raw?: BuildOptions): ResolvedBuildOptions {
+  const resolved: ResolvedBuildOptions = {
     target: 'modules',
     polyfillDynamicImport: raw?.target !== 'esnext' && !raw?.lib,
     outDir: 'dist',
@@ -207,9 +206,6 @@ export function resolveBuildOptions(
     resolved.target = 'es2019'
   }
 
-  // ensure base ending slash
-  resolved.base = resolved.base.replace(/([^/])$/, '$1/')
-
   // normalize false string into actual false
   if ((resolved.minify as any) === 'false') {
     resolved.minify = false

packages/vite/src/node/cli.ts

@@ -17,6 +17,7 @@ interface GlobalCLIOptions {
   config?: string
   c?: boolean | string
   root?: string
+  base?: string
   r?: string
   mode?: string
   m?: string
@@ -38,6 +39,7 @@ function cleanOptions(options: GlobalCLIOptions) {
   delete ret.config
   delete ret.c
   delete ret.root
+  delete ret.base
   delete ret.r
   delete ret.mode
   delete ret.m
@@ -50,6 +52,7 @@ function cleanOptions(options: GlobalCLIOptions) {
 cli
   .option('-c, --config <file>', `[string] use specified config file`)
   .option('-r, --root <path>', `[string] use specified root directory`)
+  .option('--base <path>', `[string] public base path (default: /)`)
   .option('-l, --logLevel <level>', `[string] silent | error | warn | all`)
   .option('--clearScreen', `[boolean] allow/disable clear screen when logging`)
   .option('-d, --debug [feat]', `[string | boolean] show debug logs`)
@@ -77,6 +80,7 @@ cli
     try {
       const server = await createServer({
         root,
+        base: options.base,
         mode: options.mode,
         configFile: options.config,
         logLevel: options.logLevel,
@@ -95,7 +99,6 @@ cli
 // build
 cli
   .command('build [root]')
-  .option('--base <path>', `[string] public base path (default: /)`)
   .option('--target <target>', `[string] transpile target (default: 'modules')`)
   .option('--outDir <dir>', `[string] output directory (default: dist)`)
   .option(
@@ -141,6 +144,7 @@ cli
     try {
       await build({
         root,
+        base: options.base,
         mode: options.mode,
         configFile: options.config,
         logLevel: options.logLevel,
@@ -169,6 +173,7 @@ cli
         const config = await resolveConfig(
           {
             root,
+            base: options.base,
             configFile: options.config,
             logLevel: options.logLevel
           },