Script to automatically bump semver version.

bump

#!/bin/bash
# Bumps the semantic version of the git-project.
# If no semantic version tags exist in the project, the version starts out at v0.0.0
# and is incremented by one for the field indicated by the bump command argument.

# Example Usage:

# Show the current tag 
# bump -l           

# Major bump, like 1.2.3 -> 2.0.0
# bump major This is a new Update for You

# Minor bump, like 1.2.3 -> 1.3.0
# bump minor This is a new Update for You

# Patch bump, like 1.2.3 -> 1.2.4
# bump patch This is a new Update for You

# Install directly with 
# sudo wget https://gist.githubusercontent.com/damouse/f764f2c7046ef1da42c252eea85c8a39/raw/bump -O /usr/local/bin/bump && sudo chmod +x /usr/local/bin/bump
find_latest_semver() {
  pattern="^$PREFIX([0-9]+\.[0-9]+\.[0-9]+)\$"
  versions=$(for tag in $(git tag); do
    [[ "$tag" =~ $pattern ]] && echo "${BASH_REMATCH[1]}"
  done)
  if [ -z "$versions" ];then
    echo 0.0.0
  else
    echo "$versions" | tr '.' ' ' | sort -nr -k 1 -k 2 -k 3 | tr ' ' '.' | head -1
  fi
}

# Call with (major | minor | patch) <version>
update_version() {
    case $1 in
        "major" ) major=true;;
        "minor" ) minor=true;;
        "patch" ) patch=true;;
    esac

    shift $(($OPTIND - 1))
    version=$2
    a=( ${version//./ } )

    if [ ! -z $major ]; then
        ((a[0]++))
        a[1]=0
        a[2]=0
    fi

    if [ ! -z $minor ]; then
        ((a[1]++))
        a[2]=0
    fi

    if [ ! -z $patch ]; then
        ((a[2]++))
    fi
    
    echo "${a[0]}.${a[1]}.${a[2]}"
}


bump() {
    latest_ver="${PREFIX}$(find_latest_semver)"
    latest_commit=$(git rev-parse "${latest_ver}" 2>/dev/null )
    head_commit=$(git rev-parse HEAD)
    next_ver=$(update_version $1 $latest_ver)

    shift 1
    message=$@

    if [ "$latest_commit" = "$head_commit" ]; then
        echo "refusing to tag; $latest_ver already tagged for HEAD ($head_commit)"
    else
        echo "bumping $latest_ver to $next_ver with message '$message'"
        git tag -a "$next_ver" -m "$message"
        git push --tags
    fi
}

usage() {
  echo "Usage: bump [-p prefix] <major|minor|patch> <message> | -l"
  echo "Bumps the semantic version field by one for a git-project."
  echo
  echo "Options:"
  echo "  -l  list the latest tagged version instead of bumping."
  echo "  -p  prefix [to be] used for the semver tags."
  echo ""
  echo "Example:"
  echo "  bump patch 'Fixed many bugs'"
  exit 1
}

while getopts :p:l opt; do
  case $opt in
    p) PREFIX="$OPTARG";;
    l) LIST=1;;
    \?) usage;;
    :) echo "option -$OPTARG requires an argument"; exit 1;;
  esac
done
shift $((OPTIND-1))

if [ ! -z "$LIST" ];then
  find_latest_semver
  exit 0
fi

if [ "$#" -lt 2 ]; then usage; exit 0; fi

bump_type=$1
shift 1

case $bump_type in
  major) bump major "$@";;
  minor) bump minor "$@";;
  patch) bump patch "$@";;
  *) usage
esac