Add new --matrix option to multiply commands

[cdrini]

Closes #517

Sample runs:

Single dimension:

$ dist/bin/concurrently.js --group --matrix "os:windows linux" 'echo {M:os}'
[0] windows
[0] echo windows exited with code 0
[1] linux
[1] echo linux exited with code 0

Multiple dimensions:

$ dist/bin/concurrently.js --group -M "os:windows linux" -M "version:10 12 14" 'echo {M:os} (version {M:version})'
[0] windows (version 10)
[0] echo windows (version 10) exited with code 0
[1] windows (version 12)
[1] echo windows (version 12) exited with code 0
[2] windows (version 14)
[2] echo windows (version 14) exited with code 0
[3] linux (version 10)
[3] echo linux (version 10) exited with code 0
[4] linux (version 12)
[4] echo linux (version 12) exited with code 0
[5] linux (version 14)
[5] echo linux (version 14) exited with code 0

With environment variables:

$ SERVERS="$(echo ol-web{0..2})"
$ IMAGES="python:3.12-slim python:3.13-slim"
$ dist/bin/concurrently.js --group -r -M "server:$SERVERS" -M "image:$IMAGES" 'echo ssh {M:server} docker image pull {M:image}'
ssh ol-web0 docker image pull python\:3.12-slim
ssh ol-web0 docker image pull python\:3.13-slim
ssh ol-web1 docker image pull python\:3.12-slim
ssh ol-web1 docker image pull python\:3.13-slim
ssh ol-web2 docker image pull python\:3.12-slim
ssh ol-web2 docker image pull python\:3.13-slim
ssh ol-web1 docker image pull python\:3.12-slim
ssh ol-web1 docker image pull python\:3.13-slim
ssh ol-web2 docker image pull python\:3.12-slim
ssh ol-web2 docker image pull python\:3.13-slim
ssh ol-web2 docker image pull python\:3.12-slim
ssh ol-web2 docker image pull python\:3.13-slim

[coveralls]

coverage: 99.841%. first build
when pulling cbed67a on cdrini:517/feature/matrix-option
into 7631bec on open-cli-tools:main.

[gustavohenke]

Thanks for taking this up!
I made several suggestions and asked a few questions in this pass.

I'll update the docs to mention matrices as well in a follow-up, unless you feel like doing it while keeping it on brand?

[paescuj]

@cdrini Wanna take this up again?

[cdrini]

Thank you for rebasing, @paescuj ! And thank you for the code review @gustavohenke . Apologies for the delay was a bit stuck on the right approach. Taking another look today.

[cdrini]

Ok! I updated this up with the comments. I decided to tweak the interface slightly to allow/enforce named matrix dimensions, and a M: prefix for the matrix placeholder in the command (eg --matrix "os:windows linux" 'echo {M:os}'). This not only fixes the collisions issue with the placeholder for pass-through arguments, but also avoids an issue I've noticed with GNU parallel, which is that it very quickly becomes unreadable with very many eg {1} {3} {2}. It also avoids having to have extra options for names (something GNU parallel supports IIRC), which I think fragments the interface a bit. Now there's one interface that kind of handles it all. Although at the cost of being a bit more verbose.

I updated the description with the new interface. Would love to know your thoughts!

Note: I also fixed a naming error I'd made in the code; there aren't multiple matrices, there is just one matrix!

Also if anyone has any thoughts on why that mac test is failing... 🤔 Thank you to whoever I assume re-ran it.