Git pre-commit hook to block committing Spec files with :focus => true on test blocks and .orig files from merge conflicts

pre-commit.rb

#!/usr/bin/env ruby

orig_hits = []
spec_hits = []

# In Mountion Lion Apple uses BSD grep with REG_ENHANCED enabled,
# so all regular regex special chars like ?, | and + need to be
# escaped...
def grep_focus
  if `grep --v`.match /BSD/
    'grep "\(:focus\(\s\?=>\s\?true\)\?\|focus:\s\?true\)"'
  else
    'grep -P "(:focus(\s?=>\s?true)?|focus:\s?true)"'
  end
end

# Find the names of all files that have been (A)dded (C)opied or (M)odified
filenames = `git diff --cached --name-only --diff-filter=ACM`.split("\n")

filenames.each do |filename|
  # Perform special checks for _spec filenames (rspec tests)
  if filename.match /_spec\.rb$/
    # Filter all the additions to this file, find if they contain `focus: true`
    # or `:focus => true` and store them without the initial `+` and spaces
    results = `git diff --cached  #{filename} | grep "^\+[^+]" | #{grep_focus}`.split("\n").map do |r|
      r.sub(/^\+[\s\t]*/, '')
    end

    if $? == 0
      # Add the relevant change with line number to the spec_hits array
      results.each do |r|
        spec_hits.push "#{filename}:" + `grep -n "#{r}" #{filename}`.sub(/:\s+/, ' ').chomp
      end
    end
  # Perform special checks for .orig filenames (from merge conflicts)
  elsif filename.match /\.orig$/
    orig_hits.push filename
  end
end

if spec_hits.any?
  puts "\e[33m>>> Please remove your `focus: true` from the following tests before committing\e[0m"
  puts spec_hits.join("\n")
end

if orig_hits.any?
  puts "\e[33m>>> You should not add merge conflict filenames, like these:\e[0m"
  puts orig_hits.join("\n")
end

exit 1 if spec_hits.any? || orig_hits.any?