release

#!/bin/bash
#
# Script to release app : `./release --help`
#

set -e

git_path=$(which git)
GREEN="\033[0;32m"
CYAN="\033[0;36m"
NOCOLOR="\033[0m"

target_branch="main"

usage() {
  printf "Usage : ./release [OPTION]\n\n"
  printf "This script does following steps :\n"
  printf "   * Update CHANGELOG.md\n"
  printf "   * Create commit release and tag\n"
  printf "   * Merge into release (release/x.y) branch\n\n"
  printf "Options :\n"
  printf "\t-b <branch> : Default branch to work on (default to 'main').\n"
  printf "\t-h          : Display this help.\n"
}

print_step() {
  echo -e "${GREEN}$1${NOCOLOR}"
}

print_sub_step() {
  echo -e "${CYAN}$1${NOCOLOR}"
}

while getopts ":hb:" opt; do
  case ${opt} in
  h)
    usage
    exit 1
    ;;
  b) target_branch=$OPTARG ;;
  \?)
    echo "Invalid option: -$OPTARG" 1>&2
    exit 1
    ;;
  :)
    echo "Option -$OPTARG requires an argument." >&2
    exit 1
    ;;
  esac
done
shift $((OPTIND - 1))

cd "$(dirname "$0")"

tag=$(cat version.txt)

echo "You are going to release version $tag."
read -r -p "Are you sure? [y/N] " response
if [[ ! "$response" =~ ^([yY])$ ]]; then
  echo "Exit..."
  exit 0
fi

release_branch=$(echo "$tag" | sed -Ene's#(0|[1-9][0-9]*)\.(0|[1-9][0-9]*).*#release/\1.\2#p')
repo_url=$($git_path remote -v | grep -m1 '^origin' | sed -Ene's#.*(git@[^[:space:]]*).*#\1#p' | sed -Ene's#git@(.*):(.*).git#https://\1/\2#p')

ensure_on_target_branch() {
  if [ "$($git_path symbolic-ref --short HEAD)" != "$target_branch" ]; then
    echo "You are not on $target_branch branch"
    exit 1
  fi
}

# https://github.com/git/git/blob/master/git-sh-setup.sh
require_clean_work_tree() {
  $git_path rev-parse --verify HEAD >/dev/null || exit 1
  $git_path update-index -q --ignore-submodules --refresh

  if ! $git_path diff-files --quiet --ignore-submodules; then
    echo >&2 "You have unstaged changes."
  fi

  if ! $git_path diff-index --cached --quiet --ignore-submodules HEAD --; then
    echo >&2 "Your index contains uncommitted changes."
  fi

  if [ -n "$($git_path status --porcelain)" ]; then
    echo >&2 "You have untracked files."
  fi
}

ensure_tag_dont_exist() {
  local remote=$($git_path ls-remote --tags origin "$tag")
  local local=$($git_path tag -l "$tag")
  if [ -n "$remote" ] || [ -n "$local" ]; then
    echo "Tag '$tag' exist on remote or on local"
    exit 1
  fi
}

# https://gist.github.com/rverst/1f0b97da3cbeb7d93f4986df6e8e5695
function check_version() {
  if [[ $1 =~ ^(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)(-((0|[1-9][0-9]*|[0-9]*[a-zA-Z-][0-9a-zA-Z-]*)(\.(0|[1-9][0-9]*|[0-9]*[a-zA-Z-][0-9a-zA-Z-]*))*))?(\+([0-9a-zA-Z-]+(\.[0-9a-zA-Z-]+)*))?$ ]]; then
    echo "$1"
  else
    echo ""
  fi
}

ensure_tag_format() {
  if ! $git_path check-ref-format "tags/$tag"; then
    echo "Tag '$tag' is not a valid name"
    exit 1
  fi

  semver=$(check_version "$tag")
  if [[ ! "$semver" ]]; then
    echo "Tag '$tag' doesn't follow semantic version (https://semver.org/)"
    exit 1
  fi
}

check_prerequisites() {
  ensure_tag_format
  ensure_tag_dont_exist
  ensure_on_target_branch
  require_clean_work_tree
}

prepare() {
  print_step "Preparing sources for $tag..."

  if [[ -f "CHANGELOG.md" ]]; then
    print_sub_step "  * Update CHANGELOG.md"
    ./gradlew generateChangelog -PfinalRelease >/dev/null
  fi
}


release_source() {
  print_step "Pushing release $tag..."

  $git_path add --all . >/dev/null

  print_sub_step "  * Create release commit"
  $git_path commit --quiet --allow-empty --signoff --message="Release $tag"

  print_sub_step "  * Create tag"
  $git_path tag --annotate "$tag" --message="Release $tag"

  print_sub_step "  * Push release commit and tag"
  $git_path push --quiet origin "$target_branch"
  $git_path push --quiet origin "$tag"
}

merge_in_release() {
  if [[ "${release_branch}" == "${target_branch}" ]]; then
    return
  fi

  print_step "Merging into release branch $release_branch..."

  local existed_in_local=$($git_path branch --list "$release_branch")

  if [[ -z ${existed_in_local} ]]; then
    print_sub_step "  * Creating release branch"
    $git_path checkout --quiet -b "$release_branch"
  else
    print_sub_step "  * Checkout release branch and reset from remote"
    $git_path checkout --quiet "$release_branch"
    $git_path reset --quiet --hard "origin/$release_branch"
  fi

  print_sub_step "  * Merge release on release branch"
  $git_path merge --quiet --no-edit "$target_branch"

  print_sub_step "  * Push release branch"
  $git_path push --quiet origin "$release_branch"

  $git_path checkout --quiet "$target_branch"
}

check_prerequisites
prepare
release_source
merge_in_release

echo "-------------------"
echo -e "Release '$tag' pushed on remote :"
echo -e "   \033[4m$repo_url/-/tags/$tag\033[0m"
echo -e "-> Add any necessary release notes"
echo -e "-> Creating artifacts : follow CI pipeline"
echo "-------------------"