[bug] `File could not be loaded` with `resolve.extensions: ['.vue', '.ts']`

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Describe the bug

Exception error: File could not be loaded is thrown when using resolve.extensions: ['.vue', '.ts'] with import MyComponent from './my-component' // without .vue extension

yarn run v1.22.10
warning package.json: No license field
$ vite
 > html:/Users/Carter/vite-bug/src/App.vue: error: File could not be loaded: src/v-text.vue
    2 │ import VText from './v-text';
      ╵                   ~~~~~~~~~~

error when starting dev server:
Error: Build failed with 1 error:
html:/Users/Carter/vite-bug/src/App.vue:2:18: error: File could not be loaded: src/v-text.vue
    at failureErrorWithLog (/Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:1170:15)
    at buildResponseToResult (/Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:906:32)
    at /Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:1001:20
    at /Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:553:9
    at handleIncomingPacket (/Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:642:9)
    at Socket.readFromStdout (/Users/Carter/vite-bug/node_modules/esbuild/lib/main.js:520:7)
    at Socket.emit (node:events:378:20)
    at addChunk (node:internal/streams/readable:313:12)
    at readableAddChunk (node:internal/streams/readable:288:9)
    at Socket.Readable.push (node:internal/streams/readable:227:10)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

I saw the note about custom import types. It was NOT recommended instead of NOT allowed so I believed that using resolve.extensions: ['.vue'] should work by design.

Reproduction

https://github.com/CarterLi/vite-bug

yarn && yarn dev

System Info

• vite version: 2.0.1
• Operating System: macOS 11.2
• Node version: v15.9.0
• Package manager (npm/yarn/pnpm) and version: yarn 1.22.10

Logs (Optional if provided reproduction)

N/A

[zhaozhuoboy]

This should work technically, but again, DON’T USE IT. All future Vue APIs / ecosystem tooling will all assume explicit extensions for .vue imports. You are just creating incompatibility and writing less explicit code for no good reason.

How do I retrofit an existing project to use Vite, since I developed my own business component library and released the NPM package with the omission of the Vue extension

[yyx990803]

This should work technically, but again, DON’T USE IT. All future Vue APIs / ecosystem tooling will all assume explicit extensions for .vue imports. You are just creating incompatibility and writing less explicit code for no good reason.