Git Line change calculator

count-changes

#!/usr/bin/env node
"use strict";

let exec = require("child_process").exec;

let args = process.argv.slice(2);

if(args.length <= 0) {
	console.error("You must specify at least one commit to track back to.");
	return;
}

exec(`git log ${args[0]}..${args[1] || "HEAD"} --oneline --shortstat | grep "changed,"`, (error, stdout) => {
	let input = stdout.toString().split("\n");

	let totalChanges = input.filter(line => line.indexOf('changed,') >= 0).map(line => 
		line.substr(line.indexOf('changed,') + 8)
			.replace(/(insertion(s)?\(\+\))/g, "")
			.replace(/(deletion(s)?\(\-\))/g, "")
			.split(",")
			.map(count => parseInt(count.trim()))
			.reduce((a, b) => a + b, 0)
	).reduce((a, b) => a + b, 0);

	console.log(`Total changes across ${input.length} commits: ${totalChanges}`);
});

Will sum up every addition and deletion across every commit, as far back as you specify. Will default to HEAD, unless you specify a end commit as well as a begin commit. Requires Node.js 4+.

Usage:

count-changes <begin-commit> <end-commit="HEAD">