📎 New `--changed` argument

[ematipico]

Description

Rome now has support for VCS, which means that we can unlock new features that make the life of developers easier!

One of these features is the addition of a new argument called --changed to the CLI. When we pass this argument, Rome will execute check/format/etc. only to those files that were changed.

Technical details

I am still determining the implementation of this argument. There are two alternatives:

1. execute the command via Command, we pass the proper arguments to the git program, and we read the output that was generated. Although I don't know yet what's the correct command/arguments to get an accurate output
2. Use the crate git2. While this crate is phenomenal, its size is not small (207kb)

What do you guys think?

[Conaclos]

One issue I see is that a user could expect to apply the linter/checker only on staged parts of the changed files, leaving unchecked the unstaged parts.

[ematipico]

One issue I see is that a user could expect to apply the linter/checker only on staged parts of the changed files, leaving unchecked the unstaged parts.

We wouldn't care about "what" changed in a file. We would only care about if it's changed. Even adding a white space or a new line would count as changed file, and we would need to check it ALL.