Receive "Uncaught ReferenceError: _sfc_main is not defined" when using "export" and "default" strings in one line

[klyuevtech]

Describe the bug

I receive error message in browser:
Uncaught ReferenceError: _sfc_main is not defined

when I try to use component like this:

./components/MyComponent.vue file:

<script lang="ts"> export const foo = 'default'; </script>

in App.vue file:

<script setup lang="ts"> import { foo } from './components/MyComponent.vue' const bar = foo; </script>

But when I replace 'default' word in ./components/MyComponent.vue file with anything else, for example:
./components/MyComponent.vue file:

<script lang="ts"> export const foo = 'custom'; </script>

Then all is compiled properly and I don't receive any error.

This is happening due to this reg ex in node_modules/@vue/compiler-sfc/dist/compiler-sfc.cjs.js
const namedDefaultExportRE = /((?:^|\n|;)\s*)export(.+)(?:as)?(\s*)default/s;

It gives false positives when line contains any 'default' sub-string in it.

Actually I am not sure if it is vite bug or vue one, because error goes from vite code: it does not add "const _sfc_main = {}" to compiled file in genScriptCode function of node_modules/@vitejs/plugin-vue/dist/index.cjs file, but it seems the root of the problem goes from vue script. If I should re-post this issue to vue team please let me know.

Reproduction

https://stackblitz.com/edit/vitejs-vite-xeg2wy?file=src%2Fcomponents%2FMyComponent.vue&terminal=dev

Steps to reproduce

% npm create vite@latest vitejs-vite-jtwu7b-- --template vue

% cd vitejs-vite-jtwu7b && npm i

% touch ./src/components/MyComponent.vue

% echo '<script lang="ts">
export const foo = "default";
</script>' > ./src/components/MyComponent.vue

% echo '<script setup lang="ts">
import { foo } from "./components/MyComponent.vue"
const bar = foo;
</script>' > ./src/App.vue;

% npm run dev

Now check web browser

System Info

System:
    OS: macOS 13.0
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
    Memory: 11.93 GB / 32.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 16.13.2 - /usr/local/bin/node
    Yarn: 1.22.17 - /usr/local/bin/yarn
    npm: 8.19.3 - /usr/local/bin/npm
  Browsers:
    Chrome: 107.0.5304.87
    Firefox: 106.0.5
    Safari: 16.1
  npmPackages:
    @vitejs/plugin-vue: ^3.2.0 => 3.2.0 
    vite: ^3.2.0 => 3.2.2

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.

[sapphi-red]

Since rewriteDefault function is said that it rewrites export default value into a variable value, I think this is a bug in Vue side.

vite/packages/plugin-vue/src/main.ts

Lines 324 to 328 in a9f9d31

	scriptCode = options.compiler.rewriteDefault(
	script.content,
	'_sfc_main',
	[...defaultPlugins, ...userPlugins]
	)

https://github.com/vuejs/core/blob/81a7819535c4382ba7817c817722bac6d41921d8/packages/compiler-sfc/src/rewriteDefault.ts#L9-L12

Would you create a issue to Vue?

[klyuevtech]

Hi @sapphi-red ,
Sure, I have re-posted it to vue maintenance team:
vuejs/core#7038

Would you create a issue to Vue?

[sapphi-red]

Thanks! Closing this one as the fix is coming on their side.