git pre-commit hook to prevent check-in of debugger stuff

pre-commit

#!/usr/bin/env ruby
# This pre-commit hook aims to prevent you from *accidentally* committing debugger
# statements if installed in your project. You can force a commit if necessary with:
# `git commit --no-verify`.
# Install by copying it to <your-project-dir>/.git/hooks/pre-commit'

hits = []

rb_debuggers = ['binding\.pry', 'binding\.remote_pry', 'debugger', 'focus: true', ':focus => true', 'save_and_open_page', 'save_and_open_screenshot']
js_debuggers = ['console\.log', 'debugger']

checks = {
            '_spec\.rb$' => rb_debuggers,
            '\.rb$' => rb_debuggers,
            '\.erb$' => rb_debuggers,
            '\.haml$' => rb_debuggers,
            '\.slim$' => rb_debuggers,
            '\.coffee' => js_debuggers,
            '\.js' => js_debuggers,
            '\.jsx' => js_debuggers
         }

# Find the names of all the filenames 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)
  checks.each do |filename_pattern, patterns|
    if filename.match filename_pattern
      patterns.each do |contents_pattern|
        results = `git diff --cached  #{filename} | grep "^\+[^+]" | grep "#{contents_pattern}"`.split("\n").map { |r| r.sub(/^\+[\s\t]*/, '') }
        if $? == 0
          # Add the relevant change with line number to the hits array
          results.each{ |r|
            hits.push "#{filename}:" + `grep -n '#{r}' #{filename}`.sub(/:\s+/, ' ').chomp
          }
        end
      end
    end
  end
end

if hits.any?
  puts "\e[33m>>> Please remove the following problems from these files before committing\e[0m"
  puts hits.join("\n")
  puts "or force your commit by passing --no-verify"
end

exit 1 if hits.any?