Auto version increment of tag using git post-commit hook

post-commit

#!/bin/bash

message=$(git log -1 --pretty=%B)
PATTERN="^(minor-fix|major-fix|patch): "

incrementVersion () {
  version="$1"
  major=0
  minor=0
  patch=0

  # break down the version number into it's components
  regex="([0-9]+).([0-9]+).([0-9]+)"
  if [[ $version =~ $regex ]]; then
    major="${BASH_REMATCH[1]}"
    minor="${BASH_REMATCH[2]}"
    patch="${BASH_REMATCH[3]}"
  fi

  # check paramater to see which number to increment
  case $2 in

    patch)
      build=$(echo $patch + 1 | bc)
      ;;

    minor-fix)
      minor=$(echo $minor + 1 | bc)
      ;;

    major-fix)
      major=$(echo $major+1 | bc)
      ;;

  esac

  # echo the new version number
  newVersionNumber="v${major}.${minor}.${patch}"
  if [ "$newVersionNumber" == "$version" ]; then 
    echo "Error!! Duplicate tag found"
    exit -1
  fi
  
  echo "Generated tag: " $newVersionNumber
  $(git tag ${newVersionNumber})
} 

if [[ "$message" =~ $PATTERN ]]; then
  echo  "Generating tag..."  
  latestTagVersion=$(git tag | tail -1)
  generatedTag=$latestTagVersion
  echo "Last tag version: " $latestTagVersion
  incrementVersion $latestTagVersion ${BASH_REMATCH[1]}
fi