git pre-commit hook with php syntax checking and more

git-pre-commit-php.rb

#!/usr/bin/env ruby
#
# Author: Joe Siponen <joe.siponen@gmail.com>
#
# A hook script to verify that only syntactically valid php code is commited.
#
# This hook also stops files containing the string '[[NOCOMMIT' from being committed.
# This provides an mechanism allowing you to protect yourself from committing 
# code you have added for debugging purposes by adding the string '[[NOCOMMIT'
# near the relevant section of code.
#
# Called by git-commit with no arguments. The hook should exit with non-zero status 
# after issuing an appropriate message if it wants to stop the commit.
#
# Put this code into a file called "pre-commit" inside your .git/hooks
# directory, and make sure it is executable ("chmod +x .git/hooks/pre-commit")
#
# Requires Ruby 1.8.6 or better

require 'pp'
require 'open3'
require 'strscan'
include Open3

workdir = Dir.getwd

head_verified = system('git rev-parse --verify HEAD >/dev/null') 

if head_verified
  against = 'HEAD'
else 
  # Initial commit: diff against an empty tree object
  against = '4b825dc642cb6eb9a060e54bf8d69288fbee4904'
end

# pp ENV
 
def is_php_lint_error_result(result_string)
  return result_string.chomp.size > 0
end

def read_file_from_git_index(file)
  file_index_contents_cmd = "git show :#{file}"
  file_index_contents     = nil
  
  popen3(file_index_contents_cmd) do |stdin, stdout, stderr|
    file_index_contents = stdout.read
  end

  if file_index_contents.nil? || file_index_contents.size <= 0
    $stdout.puts "Error reading #{file}: "+(file_index_contents.nil? ? 'Unreadable file' : 'Empty file')
    exit 1
  end
  
  return file_index_contents
end

changed_files = `git diff-index --diff-filter=ACMRTU --name-only -z --cached #{against}`.split("\0").inject([]) do |files, line|
  files << line.chomp
  files
end

puts "Validating PHP syntax"
php_syntax_error_files = changed_files.inject([]) do |php_syntax_error_files, file| 
  if file =~ /\.php$/  #Validate php files
    php_file_index_contents     = read_file_from_git_index(file)
  
    if php_file_index_contents.nil? || php_file_index_contents.size <= 0
      $stdout.puts "Error reading #{file}: "+(php_file_index_contents.size <= 0 ? 'Empty file' : 'Unreadable file')
      exit 1
    end
    
    puts "php -l #{file}"
    
    php_lint_result = nil
  
    popen3('php -l') do | stdin, stdout, stderr |
      stdin.puts(php_file_index_contents)
      stdin.close_write()
      php_lint_result = stderr.read()
    end
  
    if is_php_lint_error_result(php_lint_result)
      php_syntax_error_files << "file://#{File.join(workdir, file)}: #{php_lint_result.chomp}"
    end
  end
  
  php_syntax_error_files
end

#Check for the token [[NOCOMMIT in changed files and 
#stop the commit if it exists.
commit_warn_token_re      = /\[\[NOCOMMIT/

commmit_warn_line_counter = 0

commit_warned_files = changed_files.inject([]) do |commit_warned_files, file|
  file_contents       = read_file_from_git_index(file)
  
  commit_warn_scanner = StringScanner.new(file_contents)
  
  while !(commit_warn_scanner.eos?)
    matched = commit_warn_scanner.scan_until(commit_warn_token_re)
    
    break if (matched.nil? or matched.size <= 0) 
    
    matched_on_line = matched.count("\n")
    commmit_warn_line_counter += matched_on_line
    
    commit_warned_files << "file://#{File.join(workdir, file)}: [[NOCOMMIT token at line #{commmit_warn_line_counter+1}"
  end
  
  commit_warned_files
end

is_valid_commit = true

if (php_syntax_error_files.size > 0)
  $stderr.puts "\n== PHP Parse errors in: ==\n"+php_syntax_error_files.join("\n")
  is_valid_commit = false
end

if (commit_warned_files.size > 0)
  $stderr.puts "\n== Encountered [[NOCOMMIT tokens in: ==\n"+commit_warned_files.join("\n")
  is_valid_commit = false
end

if is_valid_commit == true
  $stdout.puts 'No errors/problems detected in pre-commit phase'
  # All is well
  exit 0
else
  puts
  $stdout.puts 'Aborting commit due to errors/problems detected in pre-commit phase'
  exit 1
end

First version, beta quality: trying this one out for now to see what breaks