Git pre-commit for Rubocop

pre-commit

#!/bin/sh
BRANCH=$(git branch | grep \* | cut -d ' ' -f2)
REF=$(git merge-base master $BRANCH)
DIFFS=$(git diff --diff-filter AM --name-only --relative $REF)
if [ "$DIFFS" != "" ]
then
  echo "Checking for rubocop offenses..."
  OFFENSES=$(rubocop $(echo "$DIFFS"))
  if [ "$(echo $OFFENSES | grep 'no offenses')" == "" ]
  then
    echo "$OFFENSES"
    exit 1
  else
    echo "No offenses, proceeding with commit"
  fi
fi
echo "DONE!\nYou're a good citizen... this time!\n"