Prompt for arguments?

I'm working on a large Node project that's made up of several different packages, each one with a suite of tests. I have a launch.json configuration per package to run each test suite individually. But when I'm trying to debug a single failing test, the overhead of running the entire suite can really slow things down.

In those cases, I go in and manually edit the launch.json and add some arguments to the args field to tell Mocha to only run matching tests with the -g option:

"args": ["--opts", "tests/mocha.opts", "-g", "photos should upload and return a 200 response"],

However, this isn't super discoverable for other people on the team. Ideally, I'd like to make a configuration that prompts the user to provide a string that can be passed as the argument.

I really like how ${command.PickProcess} allows me to create a dynamic configuration with a GUI to prompt me for the process to attach to. Is there any way to do something similar for an argument value? If not, can I humbly submit this as a feature request? 😄