@jannis foreign-libs preprocess option works like that. I don't remember if it can be used with node modules. The implementation should work but not sure how to use the option.

hrm I suppose we could support notion of preprocess at inputs level pre-compile

then you could file match

That would make things pretty flexible and I bet allow various small problems to be fixed on the fly.

What could that look like?

(b/build
  {:preprocess-js [{:file "node_modules/lib/symbol-observable/lib/index.js"
                    :fn (fn [ijs] ...)        ; returns an IJavaScript again
                    :method :fix-babel-output ; alternative (similar to :preprocess of :foreign-libs): a dispatch key
                    }]})

no just an arbitrary function which takes inputs before we call Closure

in order to do make this possible we need to make our pipeline more Closure like, i.e. put compiled source on the input not on disk

What does "on the input" mean in this case?

I think I understand: the compiled source would have to be available, in memory, as part of or along with the input, to the processing function, so it can efficiently read/update it instead of having to go to the disk.

When you say "input", are you referring to the IJavaScript objects (I am)?

IJavaScript is not long for this world

the input maps

but yes