Use semver to release to GitHub

semver-github-release.sh

#!/bin/bash

function log() {
    local -r level="$1"
    local -r message="$2"

    echo -e "[$level] $message"
}

function _get_bump_part() {
    local -r commit_subject="$1"

    local bump_part=$(echo $commit_subject | sed -En 's/.*\[semver:(major|minor|patch)\].*/\1/p')

    echo $bump_part
}

function _install_ghr() {
    if ! command -v go &> /dev/null; then
        log info "Installing ghr"
        echo "Go must be available in the path."
        exit 1
    fi

    go install github.com/tcnksm/ghr@latest
}

function _install_semver_tool() {
	if ! command -v semver &> /dev/null; then
        log info "Installing semver tool"
		sudo curl -sSL https://raw.githubusercontent.com/fsaintjacques/semver-tool/master/src/semver -o /usr/local/bin/semver && \
		sudo chmod +x /usr/local/bin/semver
	fi
}

function set_new_version() {
    _install_semver_tool &> /dev/null

    # Get the current commit message's subject line.
    local commit_subject=$(git log -1 --pretty=%s.)

    log info "Checking if semver prefix exists"
    if ! [[ "$commit_subject" == *"[semver"* ]]; then
        return
    fi

    log info "Getting semver bump part"
    local bump_part=$(_get_bump_part "$commit_subject")

    if [ -z "$bump_part" ]; then
        log error "Could not find find valid bump part. Should be one of [semver:(major/minor/patch)]"
        exit 1
    fi

    # We don't want to get the last tag, but rather the latest semver'd one.
    log info "Bumping ${bump_part} version"
    local latest_tag=$(git describe --abbrev=0 --tags --match "v[0-9]*")

    log info "Previous tag is: $latest_tag"
    local new_version=$(semver bump "$bump_part" "$latest_tag")

    log info "Setting new version in semver.env in NEW_VERSION variable to $new_version"
    echo NEW_VERSION=$new_version > semver.env
}

function _main() {
    # Get the current commit message's subject line.
    local commit_subject=$(git log -1 --pretty=%s.)

    if ! [[ "$commit_subject" == *"[semver"* ]]; then
        log info "Semver prefix not provided in commit subject."
        exit 0
    fi

    if [ -z "$GITHUB_TOKEN" ]; then
        echo "You must set a GITHUB_TOKEN environment variable."
        exit 1
    fi

    _install_semver_tool
    set_new_version
    source semver.env
    _install_ghr

    local release_files_path=${BUILD_ARTIFACTS_PATH:-~/workspace/}
    local latest_tag=$(git describe --abbrev=0 --tags --match "v[0-9]*")
    local changelog=$(git log --pretty=format:'* %s (%h)' "$latest_tag"..HEAD)
    local new_tag="v$NEW_VERSION"

    log info "Release info: latest_tag=$latest_tag new_tag=$new_tag release_files_path=$release_files_path"
    log info "Changelog:\n $changelog"

    ghr -token $GITHUB_TOKEN -name latest -body "${changelog}" -owner strigo -delete latest $release_files_path
    ghr -token $GITHUB_TOKEN -name $new_tag -body "${changelog}" -owner strigo -delete $new_tag $release_files_path
}

# Only run main if not sourced.
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
  _main "$@"
fi