Validate command

[cllns]

Hi there!

I'm working on using D2 in my codebase, and in my tests I'd like to just parse the file to validate that the d2 code generated is valid, without actually generating a file.

I ended up implementing this as d2 graph.d2 /dev/null, which works but I think a CLI option would be better since many people don't know about /dev/null

[alixander]

Ah that's a good idea.

I think instead of a flag, this could just serve as its own command. d2 validate input.d2.

[melsonic]

Hey @alixander, I am working on this one & I have a few questions.

1. Should this command support multiple files streamlined together or a single file.
2. Do I need to print something if the file is valid? like "inputPath is valid"

[alixander]

@melsonic Awesome!

1. I think just 1 file is fine.
2. It can print out the errors