Plugin built by esbuild cannot be loaded in vite.config.ts

[guoyunhe]

Describe the bug

I write a plugin for Vite, using a default export syntax export default myPlugin.
And I built it with esbuild. See plugin folder in the reproduction sandbox.

Then I load the plugin into my vite.config.js and run vite build. I got error:

Error: import_plugin.default is not a function

Reproduction

https://stackblitz.com/edit/vitejs-vite-k7eufn

Steps to reproduce

No response

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (6) 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: 1.22.19 - /usr/local/bin/yarn
    npm: 7.17.0 - /usr/local/bin/npm
  npmPackages:
    @vitejs/plugin-react: ^3.1.0 => 3.1.0 
    vite: ^4.1.4 => 4.1.4

Used Package Manager

npm

Logs

No response

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-k7eufn (Open reproduction)

[fi3ework]

There's an extra (for this case) default wrapper when transpiling from ESM to CJS. It's by-designed for esbuild for now, see evanw/esbuild#2026 (comment). You can remove the type: module or use a named export instead or ship a pure ESM/dual pkg.

[sapphi-red]

Vite's config works like node.js.

If you import your plugin with node.js like this, you can see it's not what you expect.

import foo from './plugin/dist/index.js'

console.log(foo)
console.log(foo.default)

Closing as this is not a bug in Vite.