Git pre-commit hook for warning about new occurrences of a string, e.g. "// TODO"

pre-commit

#!/bin/bash


# Change $stopword to whatever string you want to disallow
# N.B. It's going into a regex, so don't be ridiculous.
stopword="TODO"


########################################
# You shouldn't need to touch anything #
#          below this line             #
########################################


# Redirect output to stderr.
exec 1>&2
# enable user input
exec < /dev/tty


# Count all matches in added/modified lines (excluding filenames) in the current patch
count=$(git diff --cached | grep -e "^+" | grep -v "^+++" | grep -e $stopword | wc -l)

# CHECK
if test $count != 0
then
  echo -e "\n\033[0;31mWarning: You've added $(echo $count) occurences of \"$(echo $stopword)\" since the last commit!\n\033[0m";
  # Backup IFS delimiter
  OLD_IFS="$IFS";
  # Only split on newlines, not normal whitespace
  IFS=$'\n';
  # Get filenames of all files containing additions/modifications, and get stopword matches
  matches=($(git diff --cached | grep --color=never -e "^+++" -e "^@@" -e "^+.*$stopword"));
  # Restore previous IFS delimiter
  IFS="$OLD_IFS";
  # Loop over each result
  filename="";
  startline=0;
  endline=0;
  for i in "${matches[@]}"
  do
    if test $(echo $i | grep -e "^+++" | wc -l) != 0
    then
      # Strip out filename from unified diff header line,
      # e.g. `+++ b/config/env/local.js`
      filename=$(echo $i | sed "s/+++ [ab]\///");
    elif test $(echo $i | grep -e "^@@" | wc -l) != 0
    then
      # Strip out new line numbers from hunks header,
      # e.g. `@@ -18,6 +19,8 @@ ...`
      lines=$(echo $i | sed "s/^[^+]*+\([0-9]*,[0-9]*\).*/\1/");
      startline=$(echo $lines | sed "s/,.*//");
      endline=$(echo $lines | sed "s/[^,]*,//");
      endline=$(( $startline + $endline ))
    else
      excerpt=$(echo $i | sed "s/+\s*//");
      echo -e "\033[0;34m$filename \033[0;33m($startline-$endline): \033[0;37m$excerpt\033[0m";
    fi
  done
  echo -e "\033[0;36m";
  read -p "Are you sure want to continue (y/N)? " -n1 yn
  echo -e "\033[0m";
  echo $yn | grep -iq ^y$
  if [ $? -eq 0 ]
  then
    exit 0;
  else
    echo "Commit aborted.";
    exit 1;
  fi
fi