When I started migration process to Azure Function 3.0 of an existing project, I have discovered small, but painful inconvenience. The problem was that all function.json files were permanently removed from output folder just before Azure Function Tools func.exe was started. I have to confess it was very annoying. There were suggestions e.g. on StackOverflow or other sites to run PowerShell which copies files later – after emulator is started, but it was not a solution I like.