Cannot import from external URLs

[sagargurtu]

Describe the bug

Vitest is not able to export from external URLs.

Reproduction

Working Vite Example: https://stackblitz.com/edit/vitejs-vite-krutmh
Nonworking Vitest Example: https://stackblitz.com/edit/vitest-dev-vitest-fn6bpu?file=src%2Fbasic.js

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.18.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 9.4.2 - /usr/local/bin/npm
    pnpm: 8.14.0 - /usr/local/bin/pnpm
  npmPackages:
    @vitest/ui: latest => 1.2.0 
    vite: latest => 5.0.11 
    vitest: latest => 1.2.0

Used Package Manager

npm

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[hi-ogawa]

Thanks for the repro. FYI, Vite's SSR also doesn't support network imports yet:

• running vite.ssrLoadModule causes error when using ESM CDN for example (esm.sh) vitejs/vite#15143

Interestingly, the issue on Vitest (vite-node) might be actually different since Vite gets an error during ssrLoadModule (while transformRequest seems to be working fine). Vite-node doesn't use this API and also the error stack suggests Vitest is failing during loadAndTransform.

---

EDIT: Indeed, Vite side issue seems irrelevant. On Vitest, server.deps.external and poolOptions.threads/forks.execArgv can be used to enable nodejs's native network imports:

https://stackblitz.com/edit/vitest-dev-vitest-3ewr53?file=vite.config.ts

export default defineConfig({
  test: {
    poolOptions: {
      threads: {
        execArgv: ['--experimental-network-imports'],
      },
    },
    server: {
      deps: {
        external: [/^https:/],
      },
    },
  },
});

[sagargurtu]

Thank you for providing the workaround. Will it become the official solution, or will Vitest incorporate this logic internally?

[hi-ogawa]

I think users should be still responsible for enabling --experimental-network-imports (unless you're using Vitest browser mode, in which case the flag is probably not necessary nor relevant), but the other part external: [/^https:/] could be handled by Vitest (vite-node) automatically just like data:... is always treated as external here:

vitest/packages/vite-node/src/externalize.ts

Lines 97 to 100 in 0b28f30

	// data: should be processed by native import,
	// since it is a feature of ESM
	if (id.startsWith('data:'))
	return id