publish.yml

name: Publish Crate

on:
  push:
    branches:
      - master
    paths:
      - Cargo.toml
  repository_dispatch:
    types: publish

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Set variables
        id: vars
        run: |
          NAME=$(cargo metadata -q --no-deps | jq -r '.packages[0].name')
          VERSION=$(cargo metadata -q --no-deps | jq -r '.packages[0].version')
          echo "::set-output name=name::$NAME"
          echo "::set-output name=version::v$VERSION"
          echo "Found $NAME-$VERSION"

      - name: Lookup ${{ steps.vars.outputs.version }} tag
        id: need-release
        uses: actions/github-script@v3
        with:
          script: |
            const version = '${{ steps.vars.outputs.version }}'
            const tags = await github.repos.listTags(context.repo)
            if (tags.data.some(tag => tag.name == version)) {
                core.info(`Found ${version} tag -- will proceed with publishing`)
                return true
            }
            core.info(`Found no ${version} tag -- will skip publish step`)
            return false

      # The result from above is JSON-encoded, meaning that we
      # end up with the string 'true', not the Boolean true.
      - if: steps.need-release.outputs.result == 'true'
        name: Publish crate to crates.io
        run: |
          echo "Publishing ${{ steps.vars.outputs.name }}-${{ steps.vars.outputs.version }}"
          cargo publish --token ${{ secrets.CARGO_TOKEN }}