release-notes.yml

# Updates a release with release notes
name: release-notes

on:
  release:
    types: [published]

jobs:
  release-notes:
    runs-on: ubuntu-latest
    steps:
      - name: 🤘 checkout
        uses: actions/checkout@v2
        with: 
          submodules: recursive
          fetch-depth: 0

      - name: 🏷 current
        run: echo "CURRENT_TAG=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
      - name: 🏷 since
        run: echo "SINCE_TAG=$(git describe --abbrev=0 --tags $(git rev-list --tags --skip=1 --max-count=1))" >> $GITHUB_ENV

      - name: ⚙ changelog
        uses: faberNovel/github-changelog-generator-action@master
        if: env.SINCE_TAG != ''
        with:
          options: --token ${{ secrets.GITHUB_TOKEN }} --since-tag ${{ env.SINCE_TAG }} --o changelog.md

      - name: ⚙ changelog
        uses: faberNovel/github-changelog-generator-action@master
        if: env.SINCE_TAG == ''
        with:
          options: --token ${{ secrets.GITHUB_TOKEN }} --o changelog.md

      - name: 🖉 release
        shell: pwsh
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          $id = iwr "$env:GITHUB_API_URL/repos/$env:GITHUB_REPOSITORY/releases/tags/$env:CURRENT_TAG" | 
            select -ExpandProperty Content | 
            ConvertFrom-Json | 
            select -ExpandProperty id
            
          $notes = (Get-Content .\changelog.md | where { !($_ -like '\*') } | %{ $_.replace('\', '\\') }) -join '\n'
          $headers = @{ 'Accept'='application/vnd.github.v3+json;charset=utf-8'; 'Authorization' = "bearer $env:GITHUB_TOKEN" }
          $body = '{ "body":"' + $notes + '" }'

          # ensure we can convert to json
          $body | ConvertFrom-Json | ConvertTo-Json

          # patch & render response nicely
          iwr -Body $body "$env:GITHUB_API_URL/repos/$env:GITHUB_REPOSITORY/releases/$id" -Method PATCH -Headers $headers |
            select -ExpandProperty Content | 
            ConvertFrom-Json | 
            ConvertTo-Json