`Unable to load your Astro config` when linked cjs dependency is imported in `astro.config.ts`

Astro Info

Astro                    v4.13.1
Node                     v20.14.0
System                   Linux (x64)
Package Manager          npm
Output                   static
Adapter                  none
Integrations             none

(note that I'm commenting out cjs import to run `astro info` since otherwise it's breaking cli)

If this issue only occurs in one browser, which browser is a problem?

Describe the Bug

When cjs linked dependency is imported in astro.config.ts, it throws an error since Vite's ssrLoadModule doesn't support cjs global such as require and module.

When such dependency is only used inside app, users can workaround it by explicitly externalizing by vite.ssr.external, but that seems impossible when ssrLoadModule is used when loading astro.config.ts itself.

//// astro.config.ts

import { defineConfig } from 'astro/config';

// @ts-ignore
import testDepCjs from "test-dep-cjs";  // <-- this is linked dep
console.log(testDepCjs);

// https://astro.build/config
export default defineConfig({});

$ pnpm dev

> vite-ssr-cjs-astro-napi-rs-2206@0.0.1 dev /home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206
> astro dev

12:03:37 PM [vite] Error when evaluating SSR module /fixtures/test-dep-cjs/index.js:
|- ReferenceError: require is not defined
    at /home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206/fixtures/test-dep-cjs/index.js:2:1
    at instantiateModule (file:///home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206/node_modules/.pnpm/vite@5.3.5/node_modules/vite/dist/node/chunks/dep-mCdpKltl.js:52650:11)

12:03:37 PM [vite] Error when evaluating SSR module /home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206/astro.config.ts:
|- ReferenceError: require is not defined
    at /home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206/fixtures/test-dep-cjs/index.js:2:1
    at instantiateModule (file:///home/hiroshi/code/personal/reproductions/vite-ssr-cjs-astro-napi-rs-2206/node_modules/.pnpm/vite@5.3.5/node_modules/vite/dist/node/chunks/dep-mCdpKltl.js:52650:11)

[astro] Unable to load your Astro config

What's the expected result?

Config loads successfully.

I'm not so familiar with Astro, but when looking at the code, it looks like it's desired/planned to externalize all deps here. Perhaps, this can be switched to ssr.external: true since the linked PR is already merged long time ago.

https://github.com/withastro/astro/blob/bc2796436dc3810e988c27b71b7a66fcb1ae8bda/packages/astro/src/core/config/vite-load.ts#L14-L27

Link to Minimal Reproducible Example

https://stackblitz.com/github/hi-ogawa/reproductions/tree/main/vite-ssr-cjs-astro-napi-rs-2206?file=README.md

(note: on stackblitz, it looks like ssrFixStacktrace is also crashing so the error log is different. original code can be found in https://github.com/hi-ogawa/reproductions/tree/main/vite-ssr-cjs-astro-napi-rs-2206)

Participation

[ ] I am willing to submit a pull request for this issue.

withastro / astro