Plugins support?

Hi,

I'm using tsup for a library and I really like the simplicity.
I want to use an esbuild plugin I wrote to append ".js" or "index.js" on required imports.
To be sure I tested it in plain esbuild and it works well, but not in tsup for some reason.

The `setup` method is properly ran, but not the onLoad callback (its never called).

Is this a know issue? If not how would you debug it ?

Thanks

No repository files or tests are named. Start by comparing the plugin's setup and onLoad behavior in tsup versus plain esbuild, using the reported import-rewriting plugin behavior as the reproduction target. Done means the callback behavior is explained or corrected and covered by a regression test.

Written by the indexing model from the issue text.