I recently learned of this convention of passing -- (double-dash or dash-dash, if you will) as a cli argument, to separate options from arguments when calling a script.
What is unwritten, however, is in the case of a wrapper script, the arguments of the wrapper script become the options of the internal script.
This all came about as I was trying to debug why a particular build script didn't seem to be picking up the passed flags/arguments, and by going down the chain of commands, I found that the structure I had was essentially two wrapper scripts that eventually called the output command.
So, given what we learned, if we have two wrapper scripts and need to pass args to the final command, we have to use a double-double-dash.
npm run start -- -- --somearg