Github Actions Publish a crate from a branch

github_actions_rust_publish_branch.yml

name: "publish-branch"

on:
  push:
    branches-ignore:
      - "master"

jobs:
  npm-publish:
    name: "Publish branch"
    runs-on: ubuntu-latest
    defaults:
      run:
        shell: bash

    steps:
      ### Extract branch name
      - name: Extract branch name
        if: github.event_name != 'pull_request'
        run: echo "BRANCH_NAME=$(echo ${GITHUB_REF#refs/heads/})" >> $GITHUB_ENV
        id: extract_branch

      - name: Extract branch name
        if: github.event_name == 'pull_request'
        run: echo "BRANCH_NAME=$(echo ${GITHUB_REF#refs/heads/})" >> $GITHUB_ENV

      - name: Checkout repository
        uses: actions/checkout@v2

      ### Prepare cargo & toolchains
      - uses: actions/cache@v2
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            ~/.cargo/bin
            target
          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
      - name: Install Rust toolchain with wasm32-unknown-unknown
        uses: actions-rs/toolchain@v1
        with:
          toolchain: nightly
          profile: minimal
          override: true
      - uses: actions-rs/cargo@v1
        with:
          toolchain: nightly
          command: update
          args: --aggressive

      ### Calculate FINAL_VERSION
      - name: Install jq & sponge
        run: sudo apt-get update && sudo apt-get --yes --force-yes install jq moreutils

      - name: Install cargo-show cargo-workspaces toml-cli
        run: cargo install cargo-show cargo-workspaces toml-cli || true

      - name: Calculate the version
        run: |
          set -euo pipefail
          set -x

          # install semver and add it to PATH
          yarn global add semver
          PATH="$(yarn global bin):$PATH"

          # sanitize branch name so it can be used as a semver suffix (replace [^0-9a-zA-Z-] with hyphen)
          SANITIZED_BRANCH="$(echo -n "${{ env.BRANCH_NAME }}" | tr -C '[:alnum:]-' -)"

          CARGO_TOML="Cargo.toml"
          # get package name from Cargo.toml
          PKG_NAME="$(toml get "$CARGO_TOML" package.name | tr -d \")"

          ### CRATES.IO
          # Define accumulator array variable
          ALL_CRATES_VERSIONS=()

          # For all crates in the workspace gather all versions, filtered by branch
          for CRATE_NAME in $(cargo ws list)
          do
            CRATE_VERSIONS=$(cargo show --json "$CRATE_NAME")
            CRATE_VERSIONS_FILTERED=$(echo $CRATE_VERSIONS | jq -r ".versions[] | .num | select(contains(\"$SANITIZED_BRANCH\"))")
            ALL_CRATES_VERSIONS+=($CRATE_VERSIONS_FILTERED)
          done
          # Take the highest version of all
          MAX_CRATES_VERSION="$(semver -p ${ALL_CRATES_VERSIONS[@]} | tail -n1 || true)"
          # Increment prerelease part of the highest version
          PRERELEASE_CRATE_VERSION="$(semver --increment prerelease --preid "$SANITIZED_BRANCH" "${MAX_CRATES_VERSION}" || true)"

          ### LOCAL
          ### (NOTE: the following code assumes that local versions do not contain prerelease suffix; existing suffix will be ignored)
          # take local Rust version of the "root" crate
          LOCAL_RUST_VERSION="$(toml get "$CARGO_TOML" package.version | tr -d \")"
          LOCAL_RUST_PRERELEASE_VERSION="$(semver --increment prerelease --preid "$SANITIZED_BRANCH" "${LOCAL_RUST_VERSION}-0")" # added '-0' here to avoid semver erroneously increment patch octet. Any suffix works, '-0' is chosen deliberately.

          # take the highest version
          MAX_VERSION="$(semver "$PRERELEASE_CRATE_VERSION" "$LOCAL_RUST_PRERELEASE_VERSION" | tail -n1)"
          echo "FINAL_VERSION=$MAX_VERSION" | tee -a $GITHUB_ENV
          echo "PKG_NAME=$PKG_NAME" | tee -a $GITHUB_ENV

      ### === Rust package release ===
      - name: Login to crates.io
        run: cargo login ${{ secrets.CRATES_IO_TOKEN }}

      - name: Publish to crates.io
        run: cargo ws publish --no-git-commit --allow-dirty --yes custom "${{ env.FINAL_VERSION }}"