gistfile1.rb

#!/usr/bin/env ruby

diff_body = `git diff --staged`

# Detect whether we're adding a :focus => true line in a spec file
focus_regex = /^\+.*(describe|context|it).*:focus/

if diff_body =~ focus_regex
  puts "\nAttempting to commit a spec with :focus => true. Aborting...\n\n"

  puts diff_body

  exit 1
end