fix(react): sourcemap incorrect warning and classic runtime sourcemap

packages/plugin-react/package.json

@@ -44,6 +44,7 @@
     "@babel/plugin-transform-react-jsx-development": "^7.18.6",
     "@babel/plugin-transform-react-jsx-self": "^7.18.6",
     "@babel/plugin-transform-react-jsx-source": "^7.18.6",
+    "magic-string": "^0.26.2",
     "react-refresh": "^0.14.0"
   },
   "peerDependencies": {

packages/plugin-react/src/index.ts

@@ -3,6 +3,8 @@ import type { ParserOptions, TransformOptions, types as t } from '@babel/core'
 import * as babel from '@babel/core'
 import { createFilter, normalizePath } from 'vite'
 import type { Plugin, PluginOption, ResolvedConfig } from 'vite'
+import MagicString from 'magic-string'
+import type { SourceMap } from 'magic-string'
 import {
   addRefreshWrapper,
   isRefreshBoundary,
@@ -88,11 +90,14 @@ declare module 'vite' {
   }
 }
 
+const prependReactImportCode = "import React from 'react'; "
+
 export default function viteReact(opts: Options = {}): PluginOption[] {
   // Provide default values for Rollup compat.
   let devBase = '/'
   let resolvedCacheDir: string
   let filter = createFilter(opts.include, opts.exclude)
+  let needHiresSourcemap = false
   let isProduction = true
   let projectRoot = process.cwd()
   let skipFastRefresh = opts.fastRefresh === false
@@ -135,6 +140,8 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
       filter = createFilter(opts.include, opts.exclude, {
         resolve: projectRoot
       })
+      needHiresSourcemap =
+        config.command === 'build' && !!config.build.sourcemap
       isProduction = config.isProduction
       skipFastRefresh ||= isProduction || config.command === 'build'
 
@@ -217,6 +224,7 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
         }
 
         let ast: t.File | null | undefined
+        let prependReactImport = false
         if (!isProjectFile || isJSX) {
           if (useAutomaticRuntime) {
             // By reverse-compiling "React.createElement" calls into JSX,
@@ -261,11 +269,23 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
             // Even if the automatic JSX runtime is not used, we can still
             // inject the React import for .jsx and .tsx modules.
             if (!skipReactImport && !importReactRE.test(code)) {
-              code = `import React from 'react'; ` + code
+              prependReactImport = true
             }
           }
         }
 
+        let inputMap: SourceMap | undefined
+        if (prependReactImport) {
+          if (needHiresSourcemap) {
+            const s = new MagicString(code)
+            s.prepend(prependReactImportCode)
+            code = s.toString()
+            inputMap = s.generateMap({ hires: true, source: id })
+          } else {
+            code = prependReactImportCode + code
+          }
+        }
+
         // Plugins defined through this Vite plugin are only applied
         // to modules within the project root, but "babel.config.js"
         // files can define plugins that need to be applied to every
@@ -275,10 +295,11 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
           !babelOptions.configFile &&
           !(isProjectFile && babelOptions.babelrc)
 
+        // Avoid parsing if no plugins exist.
         if (shouldSkip) {
-          // Avoid parsing if no plugins exist.
           return {
-            code
+            code,
+            map: inputMap ?? null
           }
         }
 
@@ -326,7 +347,7 @@ export default function viteReact(opts: Options = {}): PluginOption[] {
           plugins,
           sourceMaps: true,
           // Vite handles sourcemap flattening
-          inputSourceMap: false as any
+          inputSourceMap: inputMap ?? (false as any)
         })
 
         if (result) {

playground/react-sourcemap/App.jsx

@@ -0,0 +1,8 @@
+console.log('App.jsx 1') // for sourcemap
+function App() {
+  return <div>foo</div>
+}
+
+console.log('App.jsx 2') // for sourcemap
+
+export default App

playground/react-sourcemap/__tests__/react-sourcemap.spec.ts

@@ -0,0 +1,7 @@
+import { isBuild, serverLogs } from '~utils'
+
+test.runIf(isBuild)('should not output sourcemap warning', () => {
+  serverLogs.forEach((log) => {
+    expect(log).not.toMatch('Sourcemap is likely to be incorrect')
+  })
+})

playground/react-sourcemap/index.html

@@ -0,0 +1,2 @@
+<div id="app"></div>
+<script type="module" src="main.jsx"></script>

playground/react-sourcemap/main.jsx

@@ -0,0 +1,9 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App.jsx'
+
+ReactDOM.createRoot(document.getElementById('app')).render(
+  React.createElement(App)
+)
+
+console.log('main.jsx') // for sourcemap

playground/react-sourcemap/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "test-react-sourcemap",
+  "private": true,
+  "version": "0.0.0",
+  "scripts": {
+    "dev": "vite",
+    "dev:classic": "cross-env USE_CLASSIC=1 vite",
+    "build": "vite build",
+    "build:classic": "cross-env USE_CLASSIC=1 vite build",
+    "debug": "node --inspect-brk ../../packages/vite/bin/vite",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-react": "workspace:*",
+    "cross-env": "^7.0.3"
+  }
+}

playground/react-sourcemap/vite.config.ts

@@ -0,0 +1,15 @@
+import react from '@vitejs/plugin-react'
+import type { UserConfig } from 'vite'
+
+const config: UserConfig = {
+  plugins: [
+    react({
+      jsxRuntime: process.env.USE_CLASSIC === '1' ? 'classic' : 'automatic'
+    })
+  ],
+  build: {
+    sourcemap: true
+  }
+}
+
+export default config