release-changelog

#!/bin/bash

set -e

if [[ -z "${INPUT_TAG_REGEX}" ]]; then
    echo "No 'tag_regex' input was specified"
    exit 1
fi

if [[ -z "${INPUT_VERSION_BUMP}" ]]; then
    echo "No 'version_bump' input was specified. Skipping tagging commit."
fi

TAG_REGEX=${INPUT_TAG_REGEX}
VERSION_BUMP=${INPUT_VERSION_BUMP}

git_fetch() {
    git config --global --add safe.directory "${GITHUB_WORKSPACE}"
    git fetch --depth=1 origin +refs/tags/*:refs/tags/* # Fetch all tags to get the previous tag in the next step.
    git fetch --prune --unshallow                       # Fetch all history to get all commits in the release body.
}

git_previous_tag() {
    local previous_tag
    # shellcheck disable=SC2046 disable=SC2086
    previous_tag=$(eval git tag --sort=version:refname | grep -v $(git tag --contains $(git rev-parse HEAD) | grep -E ${TAG_REGEX}) | grep -E "${TAG_REGEX}" | tail -n1)

    # If there is no tag, just get the first commit on repo
    [[ -z ${previous_tag} ]] && previous_tag=$(git rev-list --max-parents=0 HEAD)

    echo "${previous_tag}"
}

git_generate_changelog() {
    local prev_tag release_body
    prev_tag=${1}

    release_body=$(git log --no-merges "${prev_tag}".."${GITHUB_SHA}" --format='* [%h] %s (%an)')
    # See: https://github.community/t5/GitHub-Actions/set-output-Truncates-Multiline-Strings/m-p/38372#M3322
    release_body="${release_body//'%'/'%25'}"
    release_body="${release_body//$'\n'/'%0A'}"
    release_body="${release_body//$'\r'/'%0D'}"

    echo ::set-output name=release_body::"## Changelog%0A${release_body}"
}

git_next_tag() {
    local version
    version=$(git describe --abbrev=0 --tags "$(git rev-list --tags --skip=0 --max-count=1)")
    IFS=. read -r major minor patch <<<"$version"
    # Remove "v" from major
    major=${major#?}
    case $VERSION_BUMP in
        major)
            ((major++))
            minor=0
            patch=0
            ;;
        minor)
            ((minor++))
            patch=0
            ;;
        patch)
            ((patch++))
            ;;
        *)
            echo -n "Version bump input can be: major, minor or patch."
            exit 1
            ;;
    esac
    printf -v version 'v%d.%d.%d' "$((major))" "$((minor))" "$((patch))"
    echo "${version}"
}

git_tag_commit() {
    local new_tag
    new_tag=${1}
    echo "Tagging latest commit with ${new_tag}"
    git tag "${new_tag}"
    git push origin "${new_tag}"
}

git_output_latest_tag() {
  echo ::set-output name=release_tag::"$(git describe --abbrev=0 --tags "$(git rev-list --tags --skip=0 --max-count=1)")"
}

main() {
    git_fetch
    [[ -n ${VERSION_BUMP} ]] && git_tag_commit "$(git_next_tag)"
    git_generate_changelog "$(git_previous_tag)"
    git_output_latest_tag
}

main "$@"