Fail to import packages in vite.config.ts when "type": "module" is set

[sapphi-red]

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Describe the bug

When { "type": "module" } is set in package.json and config is written in TypeScript, the error below occurs with vite & vite build.

failed to load config from /Users/green/Downloads/vite-project/vite.config.ts
error when starting dev server:
TypeError [ERR_INVALID_URL]: Invalid URL: vite
    at onParseError (internal/url.js:259:9)
    at new URL (internal/url.js:335:5)
    at Loader.defaultResolve [as _resolve] (internal/modules/esm/resolve.js:790:5)
    at Loader.resolve (internal/modules/esm/loader.js:86:40)
    at Loader.getModuleJob (internal/modules/esm/loader.js:230:28)
    at ModuleWrap.<anonymous> (internal/modules/esm/module_job.js:56:40)
    at link (internal/modules/esm/module_job.js:55:36)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

Reproduction

1. Run npm init @vitejs/app and select vue-ts.
2. Add

  "type": "module"

to package.json.
3. Run npm run serve or npm run build.

System Info

• vite version: 2.0.0-beta.30
• Operating System: Windows 10
• Node version: v14.15.4
• Package manager (npm/yarn/pnpm) and version: npm 6.14.11

[CHOYSEN]

Seems like cause by 803f6da