vite build --mode=production rollup syntax error when undefined import.meta.env variable

[jschaf]

Describe the bug

Running vite build --mode=production on a TypeScript file that includes import.meta.env with an unset variable errors with Error: Unexpected token on import.meta.env.

I hit this bug attempting to upgrade Vite from 2 to 3.

TypeScript file

export const isFooEnabled = (): boolean =>
  import.meta.env.VITE_FOO === undefined || import.meta.env.VITE_FOO === 'enabled';

console.log('isFooEnabled', isFooEnabled());

Error

vite build --mode=production
vite v3.0.3 building for production...
✓ 3 modules transformed.
Unexpected token (Note that you need plugins to import files that are not JavaScript)
file: /home/projects/vitejs-vite-rw3kdr/src/main.ts:2:14
1: export const isFooEnabled = (): boolean =>
2:   import.meta.env.VITE_FOO === undefined || import.meta.env.VITE_FOO === 'enabled';
                 ^
3: 
4: console.log('isFooEnabled', isFooEnabled());
error during build:
Error: Unexpected token (Note that you need plugins to import files that are not JavaScript)
    at error (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:1888:30)
    at Module.error (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12441:16)
    at Module.tryParse (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12818:25)
    at Module.setSource (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12723:24)
    at ModuleLoader.addModuleSource (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:22165:20)

Workaround

Ensure that every import.meta.env variable is defined, like so:

 VITE_FOO=enabled vite build --mode=production

Related issues:

• Project build failed with "import.meta.env" #3304 This issue deals with import.meta.env in a string literal. That's not the case in this bug.

• Incorrect define replacement in build #8663 Looks like the same root cause but hard to tell. This bug uses the recommended VITE_ prefix. I was able to work around by defining VITE_FOO=enabled

• Support missing import.meta.env storybookjs/builder-vite#413 Looks like the same root cause which is that rollup is doing an inline replacement of import.meta.env with an object literal which leads to invalid syntax of {MODE: "production}.VITE_FOO when starting from import.meta.env.VITE_FOO.

Reproduction

https://stackblitz.com/edit/vitejs-vite-rw3kdr?file=src/main.ts

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (4) 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: 1.22.10 - /bin/yarn
    npm: 7.17.0 - /bin/npm
  npmPackages:
    vite: ^3.0.2 => 3.0.3

Used Package Manager

npm

Logs

Command:

vite build --mode=production --debug

# Workaround (note the env var goes on the vite command, not tsc)
VITE_FOO=enabled vite build --mode=production --debug

Log output (click to expand)

  vite:config no config file found. +0ms
  vite:config using resolved config: {
  vite:config   root: '/home/projects/vitejs-vite-rw3kdr',
  vite:config   base: '/',
  vite:config   mode: 'production',
  vite:config   configFile: undefined,
  vite:config   logLevel: undefined,
  vite:config   clearScreen: undefined,
  vite:config   optimizeDeps: {
  vite:config     disabled: 'build',
  vite:config     force: undefined,
  vite:config     esbuildOptions: { preserveSymlinks: undefined }
  vite: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: true,
  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: false,
  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   configFileDependencies: [],
  vite:config   inlineConfig: {
  vite:config     root: undefined,
  vite:config     base: undefined,
  vite:config     mode: 'production',
  vite:config     configFile: undefined,
  vite:config     logLevel: undefined,
  vite:config     clearScreen: undefined,
  vite:config     optimizeDeps: { force: undefined },
  vite:config     build: {}
  vite:config   },
  vite:config   resolve: { alias: [ [Object], [Object] ] },
  vite:config   publicDir: '/home/projects/vitejs-vite-rw3kdr/public',
  vite:config   cacheDir: '/home/projects/vitejs-vite-rw3kdr/node_modules/.vite',
  vite:config   command: 'build',
  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 } +4ms
vite v3.0.3 building for production...
✓ 3 modules transformed.
Unexpected token (Note that you need plugins to import files that are not JavaScript)
file: /home/projects/vitejs-vite-rw3kdr/src/main.ts:2:14
1: export const isFooEnabled = (): boolean =>
2:   import.meta.env.VITE_FOO === undefined || import.meta.env.VITE_FOO === 'enabled';
                 ^
3: 
4: console.log('isFooEnabled', isFooEnabled());
error during build:
Error: Unexpected token (Note that you need plugins to import files that are not JavaScript)
    at error (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:1888:30)
    at Module.error (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12441:16)
    at Module.tryParse (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12818:25)
    at Module.setSource (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:12723:24)
    at ModuleLoader.addModuleSource (file:///home/projects/vitejs-vite-rw3kdr/node_modules/rollup/dist/es/shared/rollup.js:22165:20)

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.

[bluwy]

You're right with #8663, and it's a duplicate of it. What happens is that Vite is incorrectly replacing that line of code into:

export const isFooEnabled = () => {}.VITE_FOO === undefined || {}.VITE_FOO === 'enabled';

which doesn't work if you paste it in your editor or browser console. A workaround would be to do:

export const isFooEnabled = (): boolean => {
  return import.meta.env.VITE_FOO === undefined || import.meta.env.VITE_FOO === 'enabled';
}

instead. Closing to keep the tracking issue at #8663.