Rollup code-split error during lib build

[lukeed]

Describe the bug

Building a library with iife and es formats selected. As soon as a dynamic import is introduced, the ESM build fails to compile:

$ vite build
vite v3.0.2 building for production...
✓ 3 modules transformed.
dist/howdy.iife.js   0.19 KiB / gzip: 0.17 KiB
dist/style.css       1.01 KiB / gzip: 0.54 KiB
Cannot split a chunk that has already been edited (1:7 – "import("./foobar")")
error during build:
Error: Cannot split a chunk that has already been edited (1:7 – "import("./foobar")")
    at MagicString._splitChunk (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:1033:10)
    at MagicString._split (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:1023:43)
    at MagicString.overwrite (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:806:8)
    at ImportExpression.renderFinalResolution (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:10250:14)
    at Chunk.finaliseDynamicImports (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:15009:22)
    at Chunk.render (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:14808:14)
    at file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:15988:52
    at Array.map (<anonymous>)
    at Bundle.addFinalizedChunksToBundle (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:15986:34)
    at Bundle.generate (file:///Users/.../node_modules/rollup/dist/es/shared/rollup.js:15966:24)

Found similar issue(s) in Rollup tracker, starting with rollup/rollup#2660

In that issue, @lukastaegert mentions "three levels of dynamic imports", so it makes me think that it may have something to do with how Vite is pitching/preparing the entry module for rollup?

Either way, even though this is a Rollup error, I cannot reproduce it when using the same source & Rollup directly.

Reproduction

https://github.com/lukeed/repro-vite-lib-split

System Info

System:
    OS: macOS 12.2.1
  Binaries:
    Node: 18.3.0 - ~/.volta/tools/image/node/18.3.0/bin/node
    Yarn: 1.22.10 - ~/.volta/tools/image/yarn/1.22.10/bin/yarn
    npm: 8.11.0 - ~/.volta/tools/image/node/18.3.0/bin/npm
  Browsers:
    Brave Browser: 86.1.15.76
    Chrome: 103.0.5060.134
    Firefox: 99.0.1
    Safari: 15.3
  npmPackages:
    vite: 3.0.2 => 3.0.2

Used Package Manager

pnpm

Logs

Click to expand!

$ vite build --debug
  vite:config bundled config file loaded in 26.67ms +0ms
  vite:config using resolved config: {
  vite:config   build: {
  vite:config     target: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari13' ],
  vite:config     polyfillModulePreload: true,
  vite:config     outDir: 'dist',
  vite:config     assetsDir: 'assets',
  vite:config     assetsInlineLimit: 4096,
  vite:config     cssCodeSplit: false,
  vite:config     cssTarget: [ 'es2020', 'edge88', 'firefox78', 'chrome87', 'safari13' ],
  vite:config     sourcemap: false,
  vite:config     rollupOptions: {},
  vite:config     minify: 'esbuild',
  vite:config     terserOptions: {},
  vite:config     write: true,
  vite:config     emptyOutDir: null,
  vite:config     manifest: false,
  vite:config     lib: { name: 'howdy', entry: 'src/main.ts', formats: [Array] },
  vite:config     ssr: false,
  vite:config     ssrManifest: 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   },
  vite:config   optimizeDeps: {
  vite:config     disabled: 'build',
  vite:config     force: undefined,
  vite:config     esbuildOptions: { preserveSymlinks: undefined }
  vite:config   },
  vite:config   configFile: '/Users/.../repro/vite.config.ts',
  vite:config   configFileDependencies: [ '/Users/.../repro/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: '/Users/.../repro',
  vite:config   base: '/',
  vite:config   resolve: { alias: [ [Object], [Object] ] },
  vite:config   publicDir: '/Users/.../repro/public',
  vite:config   cacheDir: '/Users/.../repro/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   plugins: [
  vite:config     'vite:build-metadata',
  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:watch-package-data',
  vite:config     'commonjs',
  vite:config     'vite:data-uri',
  vite:config     'vite:asset-import-meta-url',
  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:reporter',
  vite:config     'vite:load-fallback'
  vite:config   ],
  vite:config   server: {
  vite:config     preTransformRequests: true,
  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   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(0) { set: [Function (anonymous)] },
  vite:config   createResolver: [Function: createResolver],
  vite:config   worker: {
  vite:config     format: 'iife',
  vite:config     plugins: [
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object], [Object], [Object],
  vite:config       [Object]
  vite:config     ],
  vite:config     rollupOptions: {}
  vite:config   },
  vite:config   appType: 'spa',
  vite:config   experimental: { importGlobRestoreExtension: false, hmrPartialAccept: false }
  vite:config } +6ms
vite v3.0.2 building for production...
✓ 3 modules transformed.
dist/howdy.iife.js   0.19 KiB / gzip: 0.17 KiB
dist/style.css       1.01 KiB / gzip: 0.54 KiB
Cannot split a chunk that has already been edited (1:7 – "import("./foobar")")
error during build:
Error: Cannot split a chunk that has already been edited (1:7 – "import("./foobar")")
    at MagicString._splitChunk (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:1033:10)
    at MagicString._split (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:1023:43)
    at MagicString.overwrite (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:806:8)
    at ImportExpression.renderFinalResolution (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:10250:14)
    at Chunk.finaliseDynamicImports (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:15009:22)
    at Chunk.render (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:14808:14)
    at file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:15988:52
    at Array.map (<anonymous>)
    at Bundle.addFinalizedChunksToBundle (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:15986:34)
    at Bundle.generate (file:///Users/.../repro/node_modules/rollup/dist/es/shared/rollup.js:15966:24)

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.

[lukastaegert]

Without looking into it yet, I can tell you that the error message is misleading—this has nothing to do with code-splitting but rather with file transformation. The error is caused by using magic-string wrongly in some way. Still, it looks like it might be a bug in Rollup considering it happens during dynamic import rendering, where only Rollup is doing anything with magic-string.

[sapphi-red]

It seems this does not happen when format is ['es', 'iife'] instead of ['iife', 'es'].
I was able to reproduce only with rollup and I've created a issue there (rollup/rollup#4586).

[lukastaegert]

Thanks to your observation, I managed to find a fix: rollup/rollup#4589

[sapphi-red]

Thanks!

Closing as rollup 2.77.2 that includes the fix was released.