git-last-modified

#!/usr/bin/env ruby

# frozen_string_literal: true

# Usage:
# $ git-last-modified
# $ git-last-modified '*.rb'

require "bundler/inline"
require "open3"
require "shellwords"

gemfile do
  source "https://rubygems.org"
  gem "async", "~> 2.34"
end

PATHSPEC = ARGV.first.freeze

def current_files
	command = %w[git ls-files -z --exclude-standard]
	command << "--" << PATHSPEC if PATHSPEC
	last_stdout, _wait_threads = Open3.pipeline_r(command)
	last_stdout.each_line("\0", chomp: true).lazy.each do |file|
		yield file
	end
ensure
	last_stdout&.close
end

def last_modified(file)
	command = ["git", "log", "-1", "--format=%as", "--", file]
	`#{Shellwords.join(command)}`.strip
end

Barrier do |barrier|
	current_files do |file|
		barrier.async do
			date = last_modified(file)
			puts "#{date} #{file}"
		end
	end
end