The F # compiler supports folders just fine. You can keep in mind the fact that Visual Studio by default does not allow adding folders to F # projects - this is a true fact. But if you manage to add folders to the project file (either manually editing the file or F # Power Tools ), then the F # compiler will not have problems with them.
But this is still irrelevant to your case, because scripts ( fsx ) are not the same as compiled modules ( fs ). Scripts do not have a project for linking them together, but instead must #load each other to use each other. And #load can be done in any way.
For example, you can lay out your code as follows:
ProjectFolder -> Common -> Helpers.fsx -> Function1 -> function.json -> run.fsx -> Function2 -> function.json -> run.fsx
And then, in Function1/run.fsx , load the Helpers.fsx file using the relative path:
// Function1/run.fsx
As you can see from the above example, a script loaded in this way will appear in the script host as a module named after the script file.
It works, but over time it will become very dirty. I highly recommend using precompiled code instead. That way, you can put the common code into a shared library and reference it from both functions.
I highly recommend this latest video from NDC Oslo . He speaks very well about these things and much more.