Vite renaming CSS Modules filenames during build

[stefanmaric]

Describe the bug

Hi 👋

I'm trying to figure out if any given CSS asset in my build includes CSS Modules-hashed selectors.

During vite dev it is pretty easy because the injected <style> tags include the CSS source filename as data attributes, e.g.: data-vite-dev-id="/home/projects/vitejs-vite-azu81e/Isolated.module.css"

But on vite build it is renaming [name].module.css id to [js_file_name_that_imports_it]-[hash].css.

This wouldn't be a problem except for the fact that the source file is also renamed in the manifest as well:

  "counter.css": {
    "file": "assets/counter-b9e4a1e6.css",
    "src": "counter.css"
  },

I don't understand where counter.css comes from. This file doesn't exists in my working tree.

I understand why would you want to have counter-[hash].css named chunks, since one might want to merge several CSS sources into a single asset. But not having a trace to the source file sounds like a bug to me.

I'm trying to create my own mapping with a custom plugin. I can see the original .module.css source file name in the load() and transform() plugin hooks, but I don't seem to find any way to trace their journey to counter-[hash].css.

Am I missing something?

Reproduction

https://stackblitz.com/edit/vitejs-vite-azu81e?file=dist%2Fmanifest.json&terminal=dev

Steps to reproduce

Check the manifest.json file. You can re-build by opening a new terminal tab in StackBlitz and running npm run build

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 16.14.2 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 7.17.0 - /usr/local/bin/npm
  npmPackages:
    vite: ^4.3.9 => 4.3.9

Used Package Manager

npm

Logs

  vite:config bundled config file loaded in 1078.50ms +0ms
  vite:config using resolved config: {
  vite:config   build: {
  vite:config     target: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ],
  vite:config     cssTarget: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari14' ],
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     cssCodeSplit: true,
  vite:config     sourcemap: false,
  vite:config     rollupOptions: {},
  vite:config     minify: 'esbuild',
  vite:config     terserOptions: {},
  vite:config     write: true,
  vite:config     emptyOutDir: null,
  vite:config     copyPublicDir: true,
  vite:config     manifest: true,
  vite:config     lib: false,
  vite:config     ssr: false,
  vite:config     ssrManifest: false,
  vite:config     ssrEmitAssets: false,
  vite:config     reportCompressedSize: true,
  vite:config     chunkSizeWarningLimit: 500,
  vite:config     watch: null,
  vite:config     commonjsOptions: { include: [Array], extensions: [Array] },
  vite:config     dynamicImportVarsOptions: { warnOnError: true, exclude: [Array] },
  vite:config     modulePreload: { polyfill: true },
  vite:config     cssMinify: true
  vite:config   },
  vite:config   plugins: [
  vite:config     'vite:build-metadata',
  vite:config     'vite:watch-package-data',
  vite:config     'vite:pre-alias',
  vite:config     'alias',
  vite:config     'vite-plugin-inspect',
  vite:config     'vite:modulepreload-polyfill',
  vite:config     'vite:resolve',
  vite:config     'vite:html-inline-proxy',
  vite:config     'vite:css',
  vite:config     'vite:esbuild',
  vite:config     'vite:json',
  vite:config     'vite:wasm-helper',
  vite:config     'vite:worker',
  vite:config     'vite:asset',
  vite:config     'vite:wasm-fallback',
  vite:config     'vite:define',
  vite:config     'vite:css-post',
  vite:config     'vite:build-html',
  vite:config     'vite:worker-import-meta-url',
  vite:config     'vite:asset-import-meta-url',
  vite:config     'vite:force-systemjs-wrap-complete',
  vite:config     'commonjs',
  vite:config     'vite:data-uri',
  vite:config     'vite:dynamic-import-vars',
  vite:config     'vite:import-glob',
  vite:config     'vite:build-import-analysis',
  vite:config     'vite:esbuild-transpile',
  vite:config     'vite:terser',
  vite:config     'vite:manifest',
  vite:config     'vite:reporter',
  vite:config     'vite:load-fallback'
  vite:config   ],
  vite:config   optimizeDeps: {
  vite:config     disabled: 'build',
  vite:config     force: undefined,
  vite:config     esbuildOptions: { preserveSymlinks: false }
  vite:config   },
  vite:config   configFile: '/home/projects/vitejs-vite-azu81e/vite.config.ts',
  vite:config   configFileDependencies: [ '/home/projects/vitejs-vite-azu81e/vite.config.ts' ],
  vite:config   inlineConfig: {
  vite:config     root: undefined,
  vite:config     base: undefined,
  vite:config     mode: undefined,
  vite:config     configFile: undefined,
  vite:config     logLevel: undefined,
  vite:config     clearScreen: undefined,
  vite:config     optimizeDeps: { force: undefined },
  vite:config     build: {}
  vite:config   },
  vite:config   root: '/home/projects/vitejs-vite-azu81e',
  vite:config   base: '/',
  vite:config   rawBase: '/',
  vite:config   resolve: {
  vite:config     mainFields: [ 'module', 'jsnext:main', 'jsnext' ],
  vite:config     browserField: true,
  vite:config     conditions: [],
  vite:config     extensions: [
  vite:config       '.mjs',  '.js',
  vite:config       '.mts',  '.ts',
  vite:config       '.jsx',  '.tsx',
  vite:config       '.json'
  vite:config     ],
  vite:config     dedupe: [],
  vite:config     preserveSymlinks: false,
  vite:config     alias: [ [Object], [Object] ]
  vite:config   },
  vite:config   publicDir: '/home/projects/vitejs-vite-azu81e/public',
  vite:config   cacheDir: '/home/projects/vitejs-vite-azu81e/node_modules/.vite',
  vite:config   command: 'build',
  vite:config   mode: 'production',
  vite:config   ssr: {
  vite:config     format: 'esm',
  vite:config     target: 'node',
  vite:config     optimizeDeps: { disabled: true, esbuildOptions: [Object] }
  vite:config   },
  vite:config   isWorker: false,
  vite:config   mainConfig: null,
  vite:config   isProduction: true,
  vite:config   esbuild: { jsxDev: false },
  vite:config   server: {
  vite:config     preTransformRequests: true,
  vite:config     sourcemapIgnoreList: [Function: isInNodeModules],
  vite:config     middlewareMode: false,
  vite:config     fs: { strict: true, allow: [Array], deny: [Array] }
  vite:config   },
  vite:config   preview: {
  vite:config     port: undefined,
  vite:config     strictPort: undefined,
  vite:config     host: undefined,
  vite:config     https: undefined,
  vite:config     open: undefined,
  vite:config     proxy: undefined,
  vite:config     cors: undefined,
  vite:config     headers: undefined
  vite:config   },
  vite:config   envDir: '/home/projects/vitejs-vite-azu81e',
  vite:config   env: { BASE_URL: '/', MODE: 'production', DEV: false, PROD: true },
  vite:config   assetsInclude: [Function: assetsInclude],
  vite:config   logger: {
  vite:config     hasWarned: false,
  vite:config     info: [Function: info],
  vite:config     warn: [Function: warn],
  vite:config     warnOnce: [Function: warnOnce],
  vite:config     error: [Function: error],
  vite:config     clearScreen: [Function: clearScreen],
  vite:config     hasErrorLogged: [Function: hasErrorLogged]
  vite:config   },
  vite:config   packageCache: Map(1) {
  vite:config     'fnpd_/home/projects/vitejs-vite-azu81e' => {
  vite:config       dir: '/home/projects/vitejs-vite-azu81e',
  vite:config       data: [Object],
  vite:config       hasSideEffects: [Function: hasSideEffects],
  vite:config       webResolvedImports: {},
  vite:config       nodeResolvedImports: {},
  vite:config       setResolvedCache: [Function: setResolvedCache],
  vite:config       getResolvedCache: [Function: getResolvedCache]
  vite:config     },
  vite:config     set: [Function (anonymous)]
  vite:config   },
  vite:config   createResolver: [Function (anonymous)],
  vite:config   worker: {
  vite:config     format: 'iife',
  vite:config     plugins: [
  vite:config       'vite:build-metadata',
  vite:config       'vite:watch-package-data',
  vite:config       'vite:pre-alias',
  vite:config       'alias',
  vite:config       'vite:modulepreload-polyfill',
  vite:config       'vite:resolve',
  vite:config       'vite:html-inline-proxy',
  vite:config       'vite:css',
  vite:config       'vite:esbuild',
  vite:config       'vite:json',
  vite:config       'vite:wasm-helper',
  vite:config       'vite:worker',
  vite:config       'vite:asset',
  vite:config       'vite:wasm-fallback',
  vite:config       'vite:define',
  vite:config       'vite:css-post',
  vite:config       'vite:build-html',
  vite:config       'vite:worker-import-meta-url',
  vite:config       'vite:asset-import-meta-url',
  vite:config       'vite:force-systemjs-wrap-complete',
  vite:config       'commonjs',
  vite:config       'vite:data-uri',
  vite:config       'vite:worker-post',
  vite:config       'vite:dynamic-import-vars',
  vite:config       'vite:import-glob',
  vite:config       'vite:build-import-analysis',
  vite:config       'vite:esbuild-transpile',
  vite:config       'vite:terser',
  vite:config       'vite:load-fallback'
  vite:config     ],
  vite:config     rollupOptions: {},
  vite:config     getSortedPlugins: [Function: getSortedPlugins],
  vite:config     getSortedPluginHooks: [Function: getSortedPluginHooks]
  vite:config   },
  vite:config   appType: 'spa',
  vite:config   experimental: { importGlobRestoreExtension: false, hmrPartialAccept: false },
  vite:config   getSortedPlugins: [Function: getSortedPlugins],
  vite:config   getSortedPluginHooks: [Function: getSortedPluginHooks]
  vite:config } +21ms
vite v4.3.9 building for production...
transforming (1) index.html  vite:esbuild 336.88ms tsconfck init /home/projects/vitejs-vite-azu81e +0ms
✓ 9 modules transformed.
Inspect report generated at /home/projects/vitejs-vite-azu81e/.vite-inspect
dist/index.html                      0.45 kB │ gzip: 0.30 kB
dist/manifest.json                   0.73 kB │ gzip: 0.25 kB
dist/assets/javascript-8dac5379.svg  1.00 kB │ gzip: 0.60 kB
dist/assets/counter-b9e4a1e6.css     0.03 kB │ gzip: 0.05 kB
dist/assets/index-48a8825f.css       1.24 kB │ gzip: 0.65 kB
dist/assets/counter-b27d6922.js      0.22 kB │ gzip: 0.19 kB
dist/assets/index-978023f4.js        2.21 kB │ gzip: 1.10 kB
✓ built in 922ms

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 vuejs/core 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.

[stackblitz]

Start a new pull request in StackBlitz Codeflow.

• vitejs-vite-azu81e (Open reproduction)

[faga295]

IIUC, this is your expected output:

 "counter.css": {
    "file": "assets/counter-b9e4a1e6.css",
    "src": ["Isolated.module.css"]// all .module.css imported by couter.js
  },

[stefanmaric]

Indeed @faga295, would expect something along those lines; a way to tell "assets/counter-b9e4a1e6.css's content came from Isolated.module.css (and maybe others as well)".

[bluwy]

I don't understand where counter.css comes from. This file doesn't exists in my working tree.

This is fixed in #14945. On stackblitz, the manifest looks like this now

Details

{
  "counter.js": {
    "css": [
      "assets/counter-8mkbkWOV.css"
    ],
    "file": "assets/counter-JhrRzO5T.js",
    "isDynamicEntry": true,
    "src": "counter.js"
  },
  "index.html": {
    "css": [
      "assets/index-Cw8cJx0e.css"
    ],
    "dynamicImports": [
      "counter.js"
    ],
    "file": "assets/index-WIyQ0__r.js",
    "isEntry": true,
    "src": "index.html"
  }
}

It however still doesn't contain the information you need, but I think that's correct as manifest.json isn't meant to contain that information.

To get the files that consist within counter-[hash].css, you can create a Rollup plugin with the generateBundle hook, and using chunk.viteMetadata.importedCss, it should give you the information you need.

I've updated your plugin in the repro to do this: new stackblitz link