release.yml

name: GitHub Release

on:
  push:
    branches:
      - main

jobs:
  release:
    name: Create GitHub release (on version bump)
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Detect pyproject version bump
        id: detect
        shell: bash
        run: |
          set -euo pipefail

          if ! git diff --name-only "${{ github.event.before }}" "${{ github.sha }}" | grep -q '^pyproject\.toml$'; then
            echo "pyproject.toml did not change; skipping release."
            echo "changed=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          new_version="$(awk -F'"' '/^version\s*=\s*"/ {print $2; exit}' pyproject.toml)"

          before="${{ github.event.before }}"
          if [[ "$before" == "0000000000000000000000000000000000000000" ]]; then
            old_version=""
          else
            old_version="$(git show "${before}:pyproject.toml" | awk -F'"' '/^version\s*=\s*"/ {print $2; exit}' || true)"
          fi

          if [[ -z "$new_version" ]]; then
            echo "Could not parse version from pyproject.toml"
            exit 1
          fi

          echo "Old version: ${old_version:-<none>}"
          echo "New version: ${new_version}"

          if [[ "$new_version" == "$old_version" ]]; then
            echo "Version did not change; skipping release."
            echo "changed=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          echo "changed=true" >> "$GITHUB_OUTPUT"
          echo "version=${new_version}" >> "$GITHUB_OUTPUT"
          echo "tag=v${new_version}" >> "$GITHUB_OUTPUT"

      - name: Skip if tag already exists
        id: tagexists
        if: steps.detect.outputs.changed == 'true'
        shell: bash
        run: |
          set -euo pipefail
          tag="${{ steps.detect.outputs.tag }}"
          if git rev-parse -q --verify "refs/tags/${tag}" >/dev/null; then
            echo "Tag ${tag} already exists; skipping release."
            echo "skip=true" >> "$GITHUB_OUTPUT"
          else
            echo "skip=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Install uv
        if: steps.detect.outputs.changed == 'true' && steps.tagexists.outputs.skip != 'true'
        uses: astral-sh/setup-uv@v4

      - name: Build sdist and wheel
        if: steps.detect.outputs.changed == 'true' && steps.tagexists.outputs.skip != 'true'
        run: uv build

      - name: Create GitHub release
        if: steps.detect.outputs.changed == 'true' && steps.tagexists.outputs.skip != 'true'
        uses: softprops/action-gh-release@v2
        with:
          tag_name: ${{ steps.detect.outputs.tag }}
          target_commitish: ${{ github.sha }}
          generate_release_notes: true
          files: |
            dist/*