fix(ssr): throw on missing named exports in inlined modules

[bun-unsafe]

ssrLoadModule and the module runner accept import { missing } from a local ESM file. Node throws SyntaxError for the same graph.

I compared Node import() with Vite SSR on the same files. External packages already go through analyzeImportedModDifference. Inlined modules did not: processImport returned early, and inlined fetch results have no type.

This runs that ESM check after the imported module has finished evaluating, with type module. Circular graphs can observe a partial exports object, so the check is skipped until evaluation finishes.

Tests: server-runtime.spec.ts fixtures esm-internal-non-existing.js and esm-internal-existing.js.

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[bun-unsafe]

This is a bugfix, not a feature.

Node throws SyntaxError for import { missing } from a local ESM file. Vite's module runner / ssrLoadModule did not, because inlined modules skipped analyzeImportedModDifference (external packages already used that check).

The patch runs the same ESM check after the module has finished evaluating, and skips it on incomplete circular graphs so existing cycle tests stay valid. Tests are in server-runtime.spec.ts with the new fixtures.

Please review the diff. If the bot misfired, could a maintainer apply bot: skip and reopen?

[bluwy]

Is this fixing a specific issue, or one you encountered yourself?

[bun-unsafe]

No existing GitHub issue. I hit this myself.

I compared Node import() with Vite ssrLoadModule on the same local ESM files: Node throws SyntaxError for a missing named export; Vite did not. I did not find an open issue for that gap, so I sent the fix with tests.

Happy to open an issue for tracking if you prefer.

[bun-unsafe]

recheck