Git pre commit hook to run rubocop on modified files

changed_ruby_files.rb

force_skip = ['master', 'develop'].include? `git rev-parse --abbrev-ref HEAD`.strip


diff_files = []
# Note: ACMRTUXB is all file types except delete
diff_files.concat(`git --no-pager diff --name-only --diff-filter='ACMRTUXB' origin/develop...`.split(/\n/))
diff_files.concat(`git --no-pager diff --name-only --diff-filter='ACMRTUXB' --cached`.split(/\n/))
if force_skip || diff_files.empty?
  # so that rubocop doesnt run any tests
  puts '-v'
else
  puts diff_files.grep(/\.rb$/).join(' ')
end

pre-commit

#!/bin/sh
echo "Running rubocop..."
bundle exec rubocop --auto-correct --force-exclusion --fail-level autocorrect $(ruby .git/hooks/changed_ruby_files.rb)
RUBOCOP_CODE=$?
if [ $RUBOCOP_CODE -ne 0 ]; then
  exit $RUBOCOP_CODE
fi