Generate Changelogs with Conventional Commits

changelog.sh

#!/usr/bin/env bash

tag=
branch=
tag_value=
branch_value=
has_options=

print_usage() {
  name="$(basename $0)"
  printf """
Usage: 
  %s [options] /path/to/git/repo

Print changlelog for git repositories.

Options:
  -t <tag>\tCompare current revision with specified tag
  -b <branch>\tCompare current revision with specified branch

""" $name
}

# Transform long options to short ones
for arg in "$@"; do
  shift
  case "$arg" in
    "--tag") set -- "$@" "-t" ;;
    "--branch") set -- "$@" "-b" ;;
    "--help")   set -- "$@" "-h" ;;
    *)        set -- "$@" "$arg"
  esac
done

while getopts "t:b:h" reference;
do
    case $reference in
    t)  tag=1
        has_options=1
        tag_value="$OPTARG";;
    b)  branch=1
        has_options=1
        branch_value="$OPTARG";;
    h | -)  print_usage
        exit 0;;
    *)  print_usage
        exit 2;;
    esac
done

shift $(($OPTIND - 1))
path="$@"

if [ -z "$has_options" ];
then
  print_usage
  exit 2
fi

if [ -z "$path" ]; 
then
  echo "No path provided, defaulting to $(pwd)"
else
  cd $path
fi

if [ ! -z "$tag" ]; 
then
  echo "## Bugfix"
  git log  --pretty=format:'* %s' --no-merges --grep fix: "refs/tags/$tag_value"..HEAD

  echo "## Features"
  git log  --pretty=format:'* %s' --no-merges --grep feat: "refs/tags/$tag_value"..HEAD

  exit 0
fi

if [ ! -z "$branch" ]; 
then
  echo "## Bugfix"
  git log  --pretty=format:'* %s' --no-merges --grep fix: "refs/heads/$branch_value"..HEAD

  echo "## Features"
  git log  --pretty=format:'* %s' --no-merges --grep feat: "refs/heads/$branch_value"..HEAD

  exit 0
fi