Ffi/*.js in right place with 'in-source: false'?

Suppose foo.res has

import ... from "blah.js"

this works fine if the directory structure is:

some_path/foo.bs.js // generated

However, when we have 'in-source": false we now have a situation where the *.bs.js file is in lib/... but the *.js file is not copied over.

How do we have rescript copy over the *.js files to the right places ?

Don’t use "in-source": false