It is trivial to write extensions for esbuild. We've written extensive plugins to perform ast transformations that all run, collectively, in under 0.5 seconds.

It is trivial to write extensions for esbuild. We've written extensive plugins to perform ast transformations that all run, collectively, in under 0.5 seconds. Make a plugin, add acorn and escodegen. It isn't difficult. I don't see what is difficult to understand.