bin/git-wt-add

   1 #!/usr/bin/env ruby
   2
   3 ## git-wt-add: A darcs-style interactive staging script for git. As the
   4 ## name implies, git-wt-add walks you through unstaged changes on a
   5 ## hunk-by-hunk basis and allows you to pick the ones you'd like staged.
   6 ##
   7 ## git-wt-add Copyright 2007 William Morgan <wmorgan-git-wt-add@masanjin.net>.
   8 ## This program is free software: you can redistribute it and/or modify
   9 ## it under the terms of the GNU General Public License as published by
  10 ## the Free Software Foundation, either version 3 of the License, or
  11 ## (at your option) any later version.
  12 ##
  13 ## This program is distributed in the hope that it will be useful,
  14 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ## GNU General Public License for more details.
  17 ##
  18 ## You can find the GNU General Public License at:
  19 ##   http://www.gnu.org/licenses/
  20
  21 COLOR = /\e\[\d*m/
  22
  23 class Hunk
  24   attr_reader :file, :file_header, :diff
  25   attr_accessor :disposition
  26
  27   def initialize file, file_header, diff
  28     @file = file
  29     @file_header = file_header
  30     @diff = diff
  31     @disposition = :unknown
  32   end
  33
  34   def self.make_from diff
  35     ret = []
  36     state = :outside
  37     file_header = hunk = file = nil
  38
  39     diff.each do |l| # a little state machine to parse git diff output
  40       reprocess = false
  41       begin
  42         reprocess = false
  43         case
  44         when state == :outside && l =~ /^(#{COLOR})*diff --git a\/(.+) b\/(\2)/
  45           file = $2
  46           file_header = ""
  47         when state == :outside && l =~ /^(#{COLOR})*index /
  48         when state == :outside && l =~ /^(#{COLOR})*(---|\+\+\+) /
  49           file_header += l + "\n"
  50         when state == :outside && l =~ /^(#{COLOR})*@@ /
  51           state = :in_hunk
  52           hunk = l + "\n"
  53         when state == :in_hunk && l =~ /^(#{COLOR})*(@@ |diff --git a)/
  54           ret << Hunk.new(file, file_header, hunk)
  55           state = :outside
  56           reprocess = true
  57         when state == :in_hunk
  58           hunk += l + "\n"
  59         else
  60           raise "unparsable diff input: #{l.inspect}"
  61         end
  62       end while reprocess
  63     end
  64
  65     ## add the final hunk
  66     ret << Hunk.new(file, file_header, hunk) if hunk
  67
  68     ret
  69   end
  70 end
  71
  72 def help
  73   puts <<EOS
  74 y: record this patch
  75 n: don't record it
  76 w: wait and decide later, defaulting to no
  77
  78 s: don't record the rest of the changes to this file
  79 f: record the rest of the changes to this file
  80
  81 d: record selected patches, skipping all the remaining patches
  82 a: record all the remaining patches
  83 q: cancel record
  84
  85 j: skip to next patch
  86 k: back up to previous patch
  87 c: calculate number of patches
  88 h or ?: show this help
  89
  90 <Space>: accept the current default (which is capitalized)
  91 EOS
  92 end
  93
  94 def walk_through hunks
  95   skip_files, record_files = {}, {}
  96   skip_rest = record_rest = false
  97
  98   while hunks.any? { |h| h.disposition == :unknown }
  99     pos = 0
 100     until pos >= hunks.length
 101       h = hunks[pos]
 102       if h.disposition != :unknown
 103         pos += 1
 104         next
 105       elsif skip_rest || skip_files[h.file]
 106         h.disposition = :ignore
 107         pos += 1
 108         next
 109       elsif record_rest || record_files[h.file]
 110         h.disposition = :record
 111         pos += 1
 112         next
 113       end
 114
 115       puts "Hunk from #{h.file}"
 116       puts h.diff
 117       print "Shall I stage this change? (#{pos + 1}/#{hunks.length}) [ynWsfqadk], or ? for help: "
 118       c = $stdin.getc
 119       puts
 120       case c
 121       when ?y: h.disposition = :record
 122       when ?n: h.disposition = :ignore
 123       when ?w, ?\ : h.disposition = :unknown
 124       when ?s
 125         h.disposition = :ignore
 126         skip_files[h.file] = true
 127       when ?f
 128         h.disposition = :record
 129         record_files[h.file] = true
 130       when ?d: skip_rest = true
 131       when ?a: record_rest = true
 132       when ?q: exit
 133       when ?k
 134         if pos > 0
 135           hunks[pos - 1].disposition = :unknown
 136           pos -= 2 # double-bah
 137         end
 138       else
 139         help
 140         pos -= 1 # bah
 141       end
 142
 143       pos += 1
 144       puts
 145     end
 146   end
 147 end
 148
 149 def make_patch hunks
 150   patch = ""
 151   did_header = {}
 152   hunks.each do |h|
 153     next unless h.disposition == :record
 154     unless did_header[h.file]
 155       patch += h.file_header
 156       did_header[h.file] = true
 157     end
 158     patch += h.diff
 159   end
 160
 161   patch.gsub COLOR, ""
 162 end
 163
 164 ### execution starts here ###
 165
 166 diff = `git diff`.split(/\r?\n/)
 167 if diff.empty?
 168   puts "No unstaged changes."
 169   exit
 170 end
 171 hunks = Hunk.make_from diff
 172
 173 ## unix-centric!
 174 state = `stty -g`
 175 begin
 176   `stty -icanon` # immediate keypress mode
 177   walk_through hunks
 178 ensure
 179   `stty #{state}`
 180 end
 181
 182 patch = make_patch hunks
 183 if patch.empty?
 184   puts "No changes selected for staging."
 185 else
 186   IO.popen("git apply --cached", "w") { |f| f.puts patch }
 187   puts <<EOS
 188 Staged patch of #{patch.split("\n").size} lines.
 189
 190 Possible next commands:
 191   git diff --cached: see staged changes
 192          git commit: commit staged changes
 193           git reset: unstage changes
 194 EOS
 195 end
 196