`cjsModuleRunnerPlugin` transforms cjs with `require("some-package")` incorrectly when `"some-package"` exports esm

[hi-ogawa]

Related #903

It's likely what's happening is that there is cjs code

• https://unpkg.com/next@15.5.4/dist/shared/lib/app-router-context.shared-runtime.js

const _interop_require_default = require("@swc/helpers/_/_interop_require_default");

which cjsModuleRunnerPlugin transforms into:

const _interop_require_default = (await import("@swc/helpers/_/_interop_require_default")).default;

which then in turn vite import analysis resolves as esm:

const _interop_require_default = (await import(".../@swc/helpers/esm/_interop_require_default.js")).default;
// then eventually module runner transform changes:
// import -> __vite_ssr_dynamic_import__

Either we have to do:

• if we know package (in this case @swc/helpers/...) has esm variant, then we should omit default when transforming from require to `import.
• Or we somehow instruct Vite import analysis to resolve it to cjs version of package. (this doesn't sound possible)

---

• Or we check during runtime checkIfItShouldPickDefaultOrNot(await import("...")) based on some heuristics.

[hi-ogawa]

• Or we check during runtime checkIfItShouldPickDefaultOrNot(await import("...")) based on some heuristics.

I think this works. Let's do:

• inject some marker export like export const __cjs_module_runner_transform = true for modules transformed by cjsModuleRunnerPlugin.
• then checkIfItShouldPickDefaultOrNot can unwrap default only when __cjs_module_runner_transform exists.