ReScript v12 js-post-build confusion

Of course, this is our config in rescript.json:

"js-post-build": {
  "cmd": "./tools/gen.sh"
},

And the gen.sh file expects a single argument to be passed to it which is the path to the JS file that was generated by the rescript compiler. This is a relative path in the ReScript v11 build system. It’s impossible for me to know to what the path is relative – but if I had to guess, I’d say it’s relative to node_modules/rescript/. All I know is that it starts with ../../.

We use this script to compile a Flow types file from the @genType-generated TypeScript file. This is crucial for us to move forward with our rescript codebase without breaking important business features in our legacy flowtyped JS codebase.