fix: resolve CommonJS directory requires inside dependencies

[imevanc]

Problem

On Node 24+, a CommonJS require() inside a dependency flows through tsx's sync ESM hook, where directory-style specifiers (require('..'), require('process/')) were resolved to a file:// URL. Node's CommonJS resolver rejects file:// URLs in a require() context, so every candidate failed — including the real .js/.ts — and the last-tried .jsx surfaced:

Error: Cannot find module '.../node_modules/ajv/dist/compile/index.jsx'

Changes

In a CommonJS require() context, resolveDirectorySync:

• defers bare specifiers with a trailing slash (e.g. require('process/')) to Node's package resolution;
• resolves relative directories (require('..'), require('./dir/')) from a filesystem path, falling back to the directory's package.json main when no index file exists.

The ESM import path is unchanged.

Closes #800

[privatenumber]

Thanks for kicking this off, @imevanc! I pushed a commit that extends it to fix the underlying cause more broadly.

The directory resolution was handing Node's CommonJS resolver a file:// URL, which it rejects in a require() context — so even the real .js/.ts file failed and the last-tried .jsx is what surfaced. It now resolves the implicit index from a filesystem path.

That also covers two related shapes from the same code path:

• Bare package specifiers with a trailing slash. readable-stream does require('process/') to load its process dependency — the trailing slash deliberately selects the npm package over Node's builtin, so it's a bare specifier, not a relative path. tsx was resolving it against the parent dir (.../streams/process/ → index.jsx); it's now left to Node's normal package resolution.
• Directory requires that resolve through a nested package.json main.

Added regression tests for each, and CI is green across the Node matrix.

[privatenumber]

This issue is now resolved in v4.22.4.

If you're able to, your sponsorship would be very much appreciated.