Error when evaluating SSR module (Unexpected token 'export') in DEV

[livehtml]

Describe the bug

When I run pnpm run dev and load some page I've got an error in console:

3:53:23 PM [vite] Error when evaluating SSR module /.svelte-kit/dev/runtime/internal/singletons.js:
SyntaxError: Unexpected token 'export'
    at new AsyncFunction (<anonymous>)
    at instantiateModule (/home/www/sources/node_modules/.pnpm/vite@2.6.14_sass@1.43.5/node_modules/vite/dist/node/chunks/dep-e0fe87f8.js:66543:28)
3:53:23 PM [vite] Error when evaluating SSR module /.svelte-kit/dev/runtime/app/navigation.js:
SyntaxError: Unexpected token 'export'
    at new AsyncFunction (<anonymous>)
    at instantiateModule (/home/www/sources/node_modules/.pnpm/vite@2.6.14_sass@1.43.5/node_modules/vite/dist/node/chunks/dep-e0fe87f8.js:66543:28)
3:53:23 PM [vite] Error when evaluating SSR module /src/lib/Components/Base/LoginPopup.svelte:
SyntaxError: Unexpected token 'export'
    at new AsyncFunction (<anonymous>)
    at instantiateModule (/home/www/sources/node_modules/.pnpm/vite@2.6.14_sass@1.43.5/node_modules/vite/dist/node/chunks/dep-e0fe87f8.js:66543:28)
3:53:23 PM [vite] Error when evaluating SSR module /src/routes/__layout.svelte:
SyntaxError: Unexpected token 'export'
    at new AsyncFunction (<anonymous>)
    at instantiateModule (/home/www/sources/node_modules/.pnpm/vite@2.6.14_sass@1.43.5/node_modules/vite/dist/node/chunks/dep-e0fe87f8.js:66543:28)
Unexpected token 'export'
SyntaxError: Unexpected token 'export'
    at new AsyncFunction (<anonymous>)
    at instantiateModule (/home/www/sources/node_modules/.pnpm/vite@2.6.14_sass@1.43.5/node_modules/vite/dist/node/chunks/dep-e0fe87f8.js:66543:28)

But if I reload the page — no more errors until I again restart dev.

Reproduction

I can't tell exaclty why and when in happens, but looks like it's an error from packages. Probably after updating dependencies few days ago.

System Info

System:
    OS: Linux 5.4 Ubuntu 20.04.3 LTS (Focal Fossa)
    CPU: (2) x64 DO-Regular
    Memory: 249.28 MB / 3.84 GB
    Container: Yes
    Shell: 5.0.17 - /bin/bash
  Binaries:
    Node: 16.13.0 - /usr/bin/node
    npm: 8.1.0 - /usr/bin/npm
  npmPackages:
    @sveltejs/adapter-node: ^1.0.0-next.55 => 1.0.0-next.55 
    @sveltejs/adapter-static: ^1.0.0-next.21 => 1.0.0-next.21 
    @sveltejs/kit: next => 1.0.0-next.200 
    svelte: ^3.44.2 => 3.44.2

Severity

serious, but I can work around it

Additional Information

No response

[bluwy]

I created a skeleton app and run in dev but I'm not getting the errors. Please provide a reproduction so we can track this down. Thanks!

[livehtml]

Sorry, it was my mistake. But the reason of this error output totally unclear. I've just put image with wrong path (missed file):
img(src="images/default-ava.svg", alt="ava")
(I'm using svelte preprocess Pug)

So, it's really strange error output. And there is even no file where I'm put this missed image. Totally confused 🤷‍♂️

[jrmoynihan]

Having the same types of issues here. Valid Vite imports of functions in my .ts files are just failing. Seems really random.

[dominikg]

Without a proper reproduction there is nothing we can do to analyze this further. Please provide the required information.

[denizkenan]

@dominikg I have similar case here:

https://stackblitz.com/edit/sveltekit-oydoc5?file=src/lib/Chart.svelte

when used with cloudflare worker adapter build works without any issue. Dev mode throws same error mentioned in this issue.

[Rich-Harris]

The issue in the reproduction is caused by echarts exposing native JS modules without having "type": "module" in its package.json. This is a bug in that library; it should either add "type": "module" and use .cjs for the CommonJS files, or use .mjs for the modules. Either way, it should add an "exports" field to package.json. Otherwise, it won't work correctly in Node.

It can be worked around by including it in Vite's processing:

// svelte.config.js
export default {
  kit: {
    vite: {
      ssr: {
        noExternal: ['echarts']
      }
    }
  }
};

No idea what's going on with the original issue but since there's no repro there's no way for us to investigate — closing.

[csjh]

The issue in the reproduction is caused by echarts exposing native JS modules without having "type": "module" in its package.json. This is a bug in that library; it should either add "type": "module" and use .cjs for the CommonJS files, or use .mjs for the modules. Either way, it should add an "exports" field to package.json. Otherwise, it won't work correctly in Node.

It can be worked around by including it in Vite's processing:

// svelte.config.js
export default {
  kit: {
    vite: {
      ssr: {
        noExternal: ['echarts']
      }
    }
  }
};

No idea what's going on with the original issue but since there's no repro there's no way for us to investigate — closing.

This workaround isn't working anymore after the switch to Vite 3, reproduction in https://github.com/csjh/broken_kit

Edit: fixed by putting ssr: { format: 'cjs' } in vite.config.js