FR: jj diff --stat

[ocharles]

Is your feature request related to a problem? Please describe.

git diff supports the --stat option which shows the number of additions/removal per file. I like this to get an understanding of where the big changes might lie. Afaict, jj diff only has -s, which only gives me file names, but not change sizes.

Describe the solution you'd like

jj diff gains a --stat option, or -s is extended to show net LOC changes.

[PhilipMetzger]

cc @thoughtpolice, are you on it?

[martinvonz]

If not, you're probably able to do it yourself in a few hours, @ocharles. Here's the enum that defines the different formats:

jj/cli/src/diff_util.rs

Lines 65 to 72 in 28182db

	#[derive(Clone, Debug, Eq, PartialEq)]
	pub enum DiffFormat {
	Summary,
	Types,
	Git,
	ColorWords,
	Tool(Box<ExternalMergeTool>),
	}

. It shouldn't be hard to add another variant to that and copy some code from the Git variant to calculate the diff but then just count the lines instead of printing them.

[thoughtpolice]

Yes, I was intending to write a patch for this, and also unify the output with jj st, but have just been busy this week, but I'll have some more free time after tomorrow or later tonight to look at it.

[martinvonz]

Done in #2106