Generates an adds/removes-based scoreboard for a git project

gistfile1.txt

## Usage:

$ ruby git-scoreboard.rb

You can also specify a range of commits:

$ ruby git-scoreboard.rb v1.2..HEAD


## Outputs:

Most adds:
  1. Mislav Marohnic   36430
  2. Steve Jobs        4329
  3. Bill Gates        2144

Most deletes:
  1. Bill Gates        12736
  2. Mislav Marohnic   926
  3. Steve Jobs        903


## Note:

This script ignores these files:

  * extensions: sql, xml, yml
  * everything under "vendor/" or "log/"
  * Prototype and script.aculo.us

git-scoreboard.rb

#!/usr/bin/env ruby
## Scoreboard for git projects with multiple people committing.
## This is a better version of: git log --pretty=format:%an | sort | uniq -ci | sort -r | head -n30
scoreboard = {}
author = commit_id = changes_per_commit = nil
commits = []

# TODO: ignore file moves :(
ignore_mode = false
$ignore_pattern = %r!
  (?:
    \.(?: sql | xml | ya?ml ) | # ignored file extensions
    /javascripts/(?: builder|controls|effects|scriptaculous|prototype )\.js |
    (?: ^
      public/dispatch\.\w{2,4} |
      public/\d{3}.html |
      config/boot.rb
    )
  )$ |
  \b(?: vendor | log )/ # otherwise the winner would be the one who freezes rails
  !x

log = `git log --no-merges -p --pretty=format:"##%an|%h" #{ARGV.join(' ')}`

log.each_line do |line|
  if line =~ %r{^diff .+ a/(.+) b/(.+)\n$}
    ## start of a file
    path = $1
    ignore_mode = path =~ $ignore_pattern
    puts "ignored: " + path if ignore_mode and $VERBOSE
  else
    case line[0,2]
    when '##'
      ## start of a commit
      # record last commit info:
      commits << [commit_id, changes_per_commit] if commit_id
      # initialize metadata:
      author, commit_id = line[2..-2].split('|')
      scoreboard[author] ||= [0, 0]
      changes_per_commit = 0
    when '+ ', '- '
      ## the main stuff!
      unless ignore_mode
        scoreboard[author][line[0,1] == '+' ? 0 : 1] += 1
        changes_per_commit += 1
      end
    end
  end
end

everyone = scoreboard.to_a
# names with multibyte chars screw this up, but whatever:
longest_name = scoreboard.keys.compact.sort_by { |name| name.length }.last.length

def output(entries, index, width)
  entries.reverse.each_with_index do |entry, i|
    puts sprintf(' %2d. %s  %d', i + 1, entry[0].ljust(width), entry[1][index])
    break if i == 29
  end
end

puts "Most adds:"
output(everyone.sort_by { |entry| entry[1][0] }, 0, longest_name)

puts "\nMost deletes:"
output(everyone.sort_by { |entry| entry[1][1] }, 1, longest_name)

if $VERBOSE
  largest = commits.sort_by { |c| c[1] }[-4..-1].reverse.map { |c| c[0] }
  puts "\nLargest commits: #{largest.join(', ')}"
end