release.yml

name: Release

on:
  push:
    tags:
      - "*"
  workflow_dispatch:
    inputs:
      tag:
        description: "Tag to publish, for example 1.0.0"
        required: true
        type: string

permissions:
  contents: write

jobs:
  release:
    name: GitHub Release
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Create or update release
        env:
          GH_TOKEN: ${{ github.token }}
          TAG_NAME: ${{ inputs.tag || github.ref_name }}
        run: |
          set -euo pipefail

          tag="${TAG_NAME}"
          if [[ ! "${tag}" =~ ^v?[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
            echo "Skip non-semver tag: ${tag}"
            exit 0
          fi

          git fetch --tags --force
          if ! git rev-parse -q --verify "refs/tags/${tag}" >/dev/null; then
            echo "Tag does not exist: ${tag}" >&2
            exit 1
          fi

          version="${tag#v}"
          notes_file="$(mktemp)"
          awk -v version="${version}" '
            BEGIN { in_section = 0 }
            $0 ~ "^##[[:space:]]+" version "([[:space:]]|-|$)" {
              in_section = 1
              next
            }
            in_section && /^##[[:space:]]+/ {
              exit
            }
            in_section {
              print
            }
          ' CHANGELOG.md > "${notes_file}"

          if [[ ! -s "${notes_file}" ]]; then
            printf 'Release %s\n' "${tag}" > "${notes_file}"
          fi

          if gh release view "${tag}" >/dev/null 2>&1; then
            gh release edit "${tag}" --title "${tag}" --notes-file "${notes_file}"
          else
            gh release create "${tag}" --title "${tag}" --notes-file "${notes_file}" --verify-tag
          fi