The [name]-legacy-[hash].js file generated by vite@4.x and @vitejs/plugin-legacy does not have a sourcemap

[Vizards]

Describe the bug

vite@4.x could not generate a soucemap file for the [filename]-legacy-[hash].js file generated by @vitejs/plugin-legacy, but vite@3.x could successfully generate the corresponding sourcemap file.

I'm not sure if it's vite or @vitejs/plugin-legacy that's causing this problem.

I've listed two links to reproduce it below. One uses vite@4.0.4 and the other uses vite@3.2.5. Both versions of @vitejs/plugin-legacy are 3.0.1. They have the exact same configuration, and I didn't forget to add sourcemap: true to the configuration file.

Reproduction

https://stackblitz.com/edit/vitejs-v4-sourcemap-issue?file=package.json

Steps to reproduce

• Run npm run build
• Check the generated files in dist/assets/
• index-[hash].js has a sourcemap file named index-[hash].js.map. But there is no sourcemap file for index-legacy-[hash].js. (even though Vite lists its size in output for me)

The sourcemap file corresponding to index-legacy-[hash].js in vite@3.2.5 can be successfully generated. You can check the reproduction link located at https://stackblitz.com/edit/vitejs-v3-sourcemap-issue?file=package.json

System Info

  System:
    OS: macOS 12.6
    CPU: (8) arm64 Apple M1
    Memory: 275.42 MB / 16.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.18.0 - ~/.nvm/versions/node/v16.18.0/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 8.19.2 - ~/.nvm/versions/node/v16.18.0/bin/npm
  Browsers:
    Safari: 16.1
  npmPackages:
    @vitejs/plugin-legacy: ^3.0.1 => 3.0.1
    @vitejs/plugin-react: ^3.0.1 => 3.0.1
    vite: ^4.0.4 => 4.0.4

Used Package Manager

npm

Logs

Click to expand!

$ vite build --debug
  vite:config bundled config file loaded in 663.24ms +0ms
  vite:esbuild init tsconfck (root: /home/projects/vitejs-vite-edjzfv) +0ms
  vite:esbuild init tsconfck (root: /home/projects/vitejs-vite-edjzfv) +1ms
  vite:esbuild init tsconfck (root: /home/projects/vitejs-vite-edjzfv) +0ms
  vite:esbuild init tsconfck (root: /home/projects/vitejs-vite-edjzfv) +1ms
  vite:esbuild init tsconfck end +0ms
  vite:esbuild init tsconfck end +0ms
  vite:esbuild init tsconfck end +0ms
  vite:esbuild init tsconfck end +0ms
  vite:config using resolved config: {
  vite:config   build: {
  vite:config     target: [ 'es2020', 'edge79', 'firefox67', 'chrome64', 'safari11.1' ],
  vite:config     cssTarget: 'chrome61',
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     cssCodeSplit: true,
  vite:config     sourcemap: true,
  vite:config     rollupOptions: { output: [Array] },
  vite:config     minify: 'esbuild',
  vite:config     terserOptions: {},
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  vite:config     reportCompressedSize: true,
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  vite:config     'vite:legacy-generate-polyfill-chunk',
  vite:config     'vite:wasm-fallback',
  vite:config     'vite:define',
  vite:config     'vite:css-post',
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  vite:config   configFileDependencies: [ '/home/projects/vitejs-vite-edjzfv/vite.config.js' ],
  vite:config   inlineConfig: {
  vite:config     root: undefined,
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  vite:config   command: 'build',
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  vite:config   experimental: { importGlobRestoreExtension: false, hmrPartialAccept: false },
  vite:config   getSortedPlugins: [Function: getSortedPlugins],
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  vite:config } +6ms
vite v4.0.4 building for production...
✓ 34 modules transformed.
rendering chunks (1)...[@vitejs/plugin-legacy] legacy polyfills: Set(40) {
  'core-js/modules/es.object.to-string.js',
  'core-js/modules/es.promise.js',
  'core-js/modules/es.symbol.js',
  'core-js/modules/es.symbol.description.js',
  'core-js/modules/es.symbol.iterator.js',
  'core-js/modules/es.array.iterator.js',
  'core-js/modules/es.string.iterator.js',
  'core-js/modules/web.dom-collections.iterator.js',
  'core-js/modules/es.object.assign.js',
  'core-js/modules/es.error.cause.js',
  'core-js/modules/es.regexp.exec.js',
  'core-js/modules/es.string.replace.js',
  'core-js/modules/es.regexp.to-string.js',
  'core-js/modules/es.array.push.js',
  'core-js/modules/es.object.keys.js',
  'core-js/modules/web.immediate.js',
  'core-js/modules/es.set.js',
  'core-js/modules/es.regexp.test.js',
  'core-js/modules/es.array.slice.js',
  'core-js/modules/es.string.match.js',
  'core-js/modules/es.string.trim.js',
  'core-js/modules/es.object.define-property.js',
  'core-js/modules/es.reflect.to-string-tag.js',
  'core-js/modules/es.reflect.construct.js',
  'core-js/modules/es.array.includes.js',
  'core-js/modules/es.string.includes.js',
  'core-js/modules/es.object.get-own-property-descriptor.js',
  'core-js/modules/web.dom-collections.for-each.js',
  'core-js/modules/es.array.index-of.js',
  'core-js/modules/es.regexp.flags.js',
  'core-js/modules/es.math.clz32.js',
  'core-js/modules/es.map.js',
  'core-js/modules/es.array.concat.js',
  'core-js/modules/es.array.unshift.js',
  'core-js/modules/web.queue-microtask.js',
  'core-js/modules/es.weak-map.js',
  'core-js/modules/es.weak-set.js',
  'core-js/modules/es.array.splice.js',
  'core-js/modules/es.json.stringify.js',
  'core-js/modules/es.array.from.js'
}
  vite:config using resolved config: {
  vite:config   mode: 'production',
  vite:config   root: '/home/projects/vitejs-vite-edjzfv/node_modules/@vitejs/plugin-legacy/dist',
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dist/assets/polyfills-legacy-7338514e.js   66.02 kB │ gzip: 27.12 kB
dist/assets/index-legacy-6a8fcc90.js      145.45 kB │ gzip: 46.98 kB │ map: 351.98 kB
dist/index.html                   1.70 kB
dist/assets/react-35ef61ed.svg    4.13 kB
dist/assets/index-ac565ccf.css    1.44 kB │ gzip:  0.75 kB
dist/assets/index-1dca1a01.js   143.74 kB │ gzip: 46.29 kB │ map: 349.61 kB

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