Add fallback value for `require.extensions`

[auvred]

pkgr/packages/core/src/constants.ts

Lines 12 to 13 in 50bbe5c

	// eslint-disable-next-line sonarjs/deprecation
	export const EXTENSIONS = ['.ts', '.tsx', ...Object.keys(cjsRequire.extensions)]

Node.js docs (https://nodejs.org/docs/latest/api/modules.html#requireextensions) say that require.extensions is deprecated and

Avoid using require.extensions. Use could cause subtle bugs and resolving the extensions gets slower with each registered extension.

And indeed, when the CJS build of @pkgr/core is loaded using the ESM loader (when registerHooks.load is used), require.extensions is undefined, so Object.keys(cjsRequire.extensions) throws TypeError: Cannot convert undefined or null to object.

Reproduction:

// index.mjs
import { registerHooks } from 'node:module'

registerHooks({
  load(url, context, nextLoad) {
    return nextLoad(url, context)
  }
})

import('./cjs-package.cjs')

// cjs-package.cjs
require("@pkgr/core")

To reproduce it locally use:

mkdir repro
cd repro
echo '{"dependencies":{"@pkgr/core":"0.3.5"}}' > package.json
echo 'require("@pkgr/core")' > cjs-package.cjs
cat <<EOF > index.mjs
import { registerHooks } from 'node:module'

registerHooks({
  load(url, context, nextLoad) {
    return nextLoad(url, context)
  }
})

import('./cjs-package.cjs')
EOF
npm install
node index.mjs

---

I propose replacing Object.keys(cjsRequire.extensions) with something like

cjsRequire.extensions == null ? ['.js', '.json', '.node'] : Object.keys(cjsRequire.extensions)