pre-commit hook for Git that looks for certain patterns and rejects the commit if found

pre-commit-forbidden.rb

#!/usr/bin/env ruby -w

FORBIDDEN = [
	/(?<!\/\/\s)console\.log/,
	/(?<!\/\/\s)console\.debug/,
	/(?<!\/\/\s)echo print_r/,
	/\bdo not commit\b/i
]

full_diff = `git diff --cached --`

full_diff.scan(%r{^\+\+\+ b/(.+)\n@@.*\n([\s\S]*?)(?:^diff|\z)}).each do |file, diff|
	added = diff.split("\n").select { |x| x.start_with?("+") }.join("\n")
	if FORBIDDEN.any? { |re| added.match(re) }
		puts %{Please remove "#{$1 || $&}" statement from #{file} and retry commit}
		exit 1
	end
end