Sorry if this question has already been asked ( I could not find however).
I installed npm dependencies by running on moodle dir:
npm install
I also installed grunt cli as global and npx as well. Commands are working. Everything is fine except when I run 'npx grunt' adm/src/my.js files are being transpiled in same (src) directory. I think it is supposed to that grunt should output .js files inside 'build' directory.
I tested it on linux/Ubuntu. These commands are working fine. JS modules and are being outputted in 'amd/build' directory. But in windows something is wrong. Minified files are output to amd/src directory.
Windows 11
Windows 11
UPDATE: The current working solution/workaround is, install Ubuntu on windows via WSL (google it if you are unaware of it). Then use ubuntu terminal instead of windows terminal.
When running grunt on Windows, a root path has to be declared to ensure that it will only run on the desired directory.
For example: grunt amd --root=mod/quiz/amd/src/
For example: grunt amd --root=mod/quiz/amd/src/
Oh never mind, I see now this is a different issue 
