Print info about each commit for a given author

lines-per-person.js

// @ts-check
/* eslint-disable no-console */

/**
 * Calculates commit info per person in a git repo
 *
 * Run: node lines-per-person.js 'first@email.com' 'first@go.email.com' 'iamthesame@pers.on'
 */

const Git = require("nodegit");

const flatten = (a, n) => [...a, ...n];

const emails = process.argv.slice(2);

async function main() {
	const repo = await Git.Repository.open(".");
	const master = await repo.getMasterCommit();
	const history = master.history();
	const commits = [];

	history.on("commit", async function (commit) {
		const author = commit.author();
		const authorEmail = author.email();

		if (!emails.some(e => e === authorEmail)) {
			return;
		}

		const diff = await commit.getDiff();
		const patches = (await Promise.all(diff.map(d => d.patches()))).reduce(flatten, []);
		const stats = patches.map(p => p.lineStats());
		const changes = stats.reduce(([a, d, c], {
			total_additions: na,
			total_context: nc,
			total_deletions: nd
		}) => [a + na, d + nd, c + nc], [0, 0, 0]);

		const t = new Date(commit.time() * 1000);
		const p = s => s < 10 ? `0${ s }` : s;
		const ts = `${ t.getFullYear() }-${ p( t.getMonth() + 1 ) }-${ p( t.getDate() ) } ${ p( t.getHours() ) }:${ p( t.getMinutes() ) }:${ p( t.getSeconds() ) }`;

		commits.push([commit.sha(), ts, ...changes, changes[0] - changes[1]]);
	});

	history.start();

	history.on('end', () => {
		console.log('Commit Hash;Date;Added;Removed;Context');
		commits
			.sort((a, b) => a[1].localeCompare(b[1]))
			.reduce((cs, c, i) => [...cs, [...c, i > 0 ? cs[i - 1][6] + c[5] : c[5]]], [])
			.forEach(l => console.log(l.join(';')));
	});
}

main();