C# projects, add mechanism of being able to run custom action for invidividual file

In C++ projects I'm including .lua configuration script as customly built file, for example like this:

vpaths { ["*"] = { lua2compile } }
files { lua2compile }

filter ("files:**" .. lua2compile )
buildrule {
     description = 'Generating project from $(SolutionName).lua file',
     commands = 
         "    premake5.exe --file=\"%Lua%\" " .. buildvsver .. "\r\n" ..
         ")\r\n" ..
         "echo 1>$(IntDir)" .. stateFile
     ,
     outputs = { "$(IntDir)" .. stateFile }
}        
filter {}

But I miss for C# to do the same.

There exists "buildaction", but currently you cannot specify custom command for it.

files { includedFrom }
filter ( "files:**" .. includedFrom )
buildaction "Compile"
filter { }

Using it as "Compile" - tries to compile .lua script, but not to use premake5.exe.

This is an important feature for integrating premake5 to be used for C# based projects.

Someone might claim that you have pre/post build steps for C# projects, that's true - but it's not sufficient. Typically you're modifying .lua script and building / compiling only it & reload project.

Start at the C# project generation path and trace the existing buildaction handling, then compare it with the buildrule example shown for C++ projects. Define the expected behavior for a custom command attached to an individual file, including how it avoids compiling the Lua file, and verify the generated C# project reflects that action.