generate-changelog

#!/bin/bash -e

fatal() { echo "fatal [$(basename $0)]: $@" 1>&2; exit 1; }

usage() {
cat<<EOF
Syntax: $0
Convenience script to output updated CHANGELOG.md for manual editing

Notes::
    
    - auto-increments major.minor.PATCH from latest git tag (or 0.1.0)
    - includes short git log of changes since latest git tag (or all)

EOF
exit 1
}

increment_version() {
    version=$1
    last_char=${version#${version%?}}
    echo $version | sed 's/[0-9]$/'"$((last_char+1))"'/'
}

get_log() {
    since=$1
    [ "$since" ] && between=$since..HEAD
    git --no-pager log $between --reverse --pretty=format:'- %s'
}

[[ "$#" = "0" ]] || usage

latest=$(git tag -l | head -1)
gitlog=$(get_log $latest)
[ "$latest" ] && version=$(increment_version $latest)

echo -e "## ${version:-0.1.0}\n"
echo -e "<replace with high level summary>\n"
echo -e "#### New features\n"
echo -e "#### Bugfixes\n"
echo "${gitlog}" | grep -i fix && echo || true
echo -e "#### Other changes\n"
echo "${gitlog}" | grep -vi fix && echo || true
[ -e CHANGELOG.md ] && cat CHANGELOG.md

exit 0