Error: Using declaration is not enabled. Set jsc.parser.usingDecl to true

[justjake]

Describe the bug

I am using a stock, default vite build, and trying to adopt the using statement supported by Typescript 5.2: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-5-2.html#using-declarations-and-explicit-resource-management

This results in an error:

Using declaration is not enabled. Set jsc.parser.usingDecl to true
file: /home/projects/vitejs-vite-94zdjw/main.js:6:0
4: import { setupCounter } from './counter.js'
5: 
6: using _x = 1
   ^
7: 
8: document.querySelector('#app').innerHTML = `
error during build:
RollupError: Using declaration is not enabled. Set jsc.parser.usingDecl to true
    at error (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:468:30)
    at nodeConverters (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:2215:9)
    at convertNode (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:1100:12)
    at convertProgram (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:1091:48)
    at Module.parseAstAsync (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:2281:20)
    at async Module.tryParseAsync (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:13538:21)
    at async Module.setSource (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:13119:35)
    at async ModuleLoader.addModuleSource (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:17782:13)

Note that the error advises:

Set jsc.parser.usingDecl to true

I tried putting this in vite.config.js, but it didn't typecheck and had no effect on the error. I think it's an SWC option, and I don't see a way to pass options to SWC.

Reproduction

https://stackblitz.com/edit/vitejs-vite-94zdjw?file=main.js

Steps to reproduce

Add a using statement to a new vite project, like using _x = 1.

System Info

$ npx envinfo --system --npmPackages '{vite,@vitejs/*,rollup}' --binaries --browsers

Need to install the following packages:
envinfo@7.11.0
Ok to proceed? (y)

  System:
    OS: macOS 14.0
    CPU: (8) arm64 Apple M2
    Memory: 95.41 MB / 24.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.10.0 - ~/Library/pnpm/node
    Yarn: 4.0.2 - ~/Library/pnpm/yarn
    npm: 10.2.3 - ~/Library/pnpm/npm
    pnpm: 8.12.0 - ~/Library/pnpm/pnpm
  Browsers:
    Chrome: 120.0.6099.129
    Safari: 17.0
  npmPackages:
    @vitejs/plugin-vue: ^4.5.2 => 4.5.2
    vite: ^5.0.8 => 5.0.10

Used Package Manager

npm

Logs

Click to expand!

~/projects/vitejs-vite-94zdjw
❯ npx vite build --debug
  vite:config no config file found. +0ms
  vite:config using resolved config: {
  vite:config   root: '/home/projects/vitejs-vite-94zdjw',
  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: false }
  vite: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: false,
  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   configFileDependencies: [],
  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   rawBase: '/',
  vite:config   resolve: {
  vite:config     mainFields: [ 'browser', 'module', 'jsnext:main', 'jsnext' ],
  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-94zdjw/public',
  vite:config   cacheDir: '/home/projects/vitejs-vite-94zdjw/node_modules/.vite',
  vite:config   command: 'build',
  vite:config   ssr: {
  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: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: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   css: { lightningcss: undefined },
  vite:config   esbuild: { jsxDev: false },
  vite:config   server: {
  vite:config     preTransformRequests: true,
  vite:config     sourcemapIgnoreList: [Function: isInNodeModules$1],
  vite:config     middlewareMode: false,
  vite:config     fs: {
  vite:config       strict: true,
  vite:config       allow: [Array],
  vite:config       deny: [Array],
  vite:config       cachedChecks: false
  vite:config     }
  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-94zdjw',
  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-94zdjw' => {
  vite:config       dir: '/home/projects/vitejs-vite-94zdjw',
  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: createResolver],
  vite:config   worker: { format: 'iife', plugins: '() => plugins', rollupOptions: {} },
  vite:config   appType: 'spa',
  vite:config   experimental: { importGlobRestoreExtension: false, hmrPartialAccept: false },
  vite:config   getSortedPlugins: [Function: getSortedPlugins],
  vite:config   getSortedPluginHooks: [Function: getSortedPluginHooks]
  vite:config } +3ms
vite v5.0.10 building for production...
✓ 3 modules transformed.
Using declaration is not enabled. Set jsc.parser.usingDecl to true
file: /home/projects/vitejs-vite-94zdjw/main.js:6:0
4: import { setupCounter } from './counter.js'
5: 
6: using _x = 1
   ^
7: 
8: document.querySelector('#app').innerHTML = `
error during build:
RollupError: Using declaration is not enabled. Set jsc.parser.usingDecl to true
    at error (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:468:30)
    at nodeConverters (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:2215:9)
    at convertNode (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:1100:12)
    at convertProgram (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:1091:48)
    at Module.parseAstAsync (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/parseAst.js:2281:20)
    at async Module.tryParseAsync (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:13538:21)
    at async Module.setSource (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:13119:35)
    at async ModuleLoader.addModuleSource (/home/projects/vitejs-vite-94zdjw/node_modules/rollup/dist/es/shared/node-entry.js:17782:13)

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-94zdjw (Open reproduction)

[sapphi-red]

Rollup doesn't support using declaration yet (rollup/rollup#5113) (also the browser doesn't support it yet) and requires to be transpiled. You need to configure it like:

export default defineConfig({
  esbuild: {
    target: 'es2020',
    include: /\.(m?[jt]s|[jt]sx)$/,
    exclude: []
  }
})

Note that this configuration will make all files to be transpiled by esbuild, to make it more performant, only run the transpile on the files using using by creating a plugin.

If you just need to enable it in .ts files, setting esbuild.target: 'es2020' will suffice.

related: #13756

[jrnail23]

@sapphi-red, I'm having the same issue with vitest, but I'm polyfilling the dispose implementation if needed -- this works fine with plain tsc, but is there any way around the parsing error? Perhaps some sort of pragma that can tell vite/rollup/esbuild to ignore it?

[neko-para]

Rollup doesn't support using declaration yet (rollup/rollup#5113) (also the browser doesn't support it yet) and requires to be transpiled. You need to configure it like:

export default defineConfig({
  esbuild: {
    target: 'es2020',
    include: /\.(m?[jt]s|[jt]sx)$/,
    exclude: []
  }
})

Note that this configuration will make all files to be transpiled by esbuild, to make it more performant, only run the transpile on the files using using by creating a plugin.

If you just need to enable it in .ts files, setting esbuild.target: 'es2020' will suffice.

related: #13756

This seems only works in built mode. As in dev mode, no transpilers are involved. So is it possible to make a plugin to convert them? Or maybe I have to use watch mode instead of dev mode.

---

Found out that vite has emulated rollup build hooks in development mode, so it's possible to call esbuild to transform code.
Here's an example.

import { transform } from 'esbuild'
// ...
  plugins: [
    vue(),
    vueJsx(),
    {
      name: 'esbuild-transform',
      async transform(code, id, options) {
        if (id.endsWith('.ts') || id.endsWith('.vue')) {
          code = (
            await transform(code, {
              target: 'es2022'
            })
          ).code
        }
        return code
      }
    }
  ],

[sapphi-red]

Closing as this is now supported by rollup since v4.14.0.