Vite SSR doesn't support "Arbitrary Module Namespace Identifiers"

[hi-ogawa]

Describe the bug

We had a report on Vitest vitest-dev/vitest#5851 and it looks like the issue is in Vite's SSR transform.

// file-2.js
const something = "Something";

export { something as "arbitrary string" };

export { something as normalIdentifier };

# [OK] import from node
$ node repro-node.js
[Module: null prototype] {
  'arbitrary string': 'Something',
  normalIdentifier: 'Something'
}

# [NOT OK] import from Vite ssrLoadModule
$ node repro-vite.js
{
  undefined: [Getter],
  normalIdentifier: [Getter],
  [Symbol(Symbol.toStringTag)]: 'Module'
}

# [OK] import from Vite client
$ pnpm dev

links

• spec Normative: Arbitrary module namespace identifier names tc39/ecma262#2154
• typescript support Implement "Arbitrary Module Namespace Identifiers" microsoft/TypeScript#58640
• vitest issue String exports aren't resolved on wildcard imports vitest-dev/vitest#5851

Reproduction

https://github.com/hi-ogawa/reproductions/tree/main/vite-ssr-arbitrary-module-namespace-identifier

Steps to reproduce

Also on stackblitz https://stackblitz.com/github/hi-ogawa/reproductions/tree/main/vite-ssr-arbitrary-module-namespace-identifier

System Info

(stackblitz)

  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: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vite: ^5.2.13 => 5.2.13

Used Package Manager

pnpm

Logs

No response

Validations

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• Read the Contributing Guidelines.
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• The provided reproduction is a minimal reproducible example of the bug.