action.yml

name: "Find Minimum Required Rust Version"

description: "Runs cargo-msrv on multiple paths and finds the highest minimum Rust version required."
author: "derrix060"

branding:
  icon: "eye"
  color: "red"

inputs:
  paths:
    description: "Comma-separated list of paths to run cargo-msrv.  Defaults to the current directory"
    default: "."

outputs:
  highest-msrv:
    description: "The highest minimum Rust version required."
    value: ${{ steps.cargo-msrv.outputs.highest-msrv }}

runs:
  using: "composite"
  steps:
    - name: Setup Rust
      uses: actions-rust-lang/setup-rust-toolchain@v1
      with:
        components: cargo

    - name: Install cargo-msrv
      shell: bash
      run: cargo install cargo-msrv

    - name: Setup jq
      uses: dcarbone/install-jq-action@v3.0.1

    - name: Run cargo-msrv for each path
      id: cargo-msrv
      shell: bash
      run: |
        set -euxo pipefail

        # Split the input paths by commas
        IFS=',' read -r -a paths <<< "${{ inputs.paths }}"
        
        # Initialize the highest version variable
        highest_msrv="0.0.0"

        # Function to compare versions
        compare_versions() {
          if [[ "$1" == "$2" ]]; then
            echo 0
          elif [[ "$1" == "$(echo -e "$1\n$2" | sort -Vr | head -n1)" ]]; then
            echo 1
          else
            echo 2
          fi
        }

        # Loop through all paths and run cargo-msrv
        for path in "${paths[@]}"; do
          echo "Running cargo-msrv for $path"
          cargo msrv find --path $path --output-format json --no-log  2>&1 | tee logs.txt
          version=$(tail -1 logs.txt | jq -r '.result.version')
          if [[ "$version" == "null" ]]; then
            echo "Could not find MSRV for $path"
            exit 1
          fi

          echo "Found MSRV $version for $path"

          # Compare and store the highest version
          result=$(compare_versions $highest_msrv $version)
          if [[ "$result" -eq "2" ]]; then
            echo "Found higher MSRV $version than $highest_msrv"
            highest_msrv=$version
          fi
        done

        echo "The highest MSRV is $highest_msrv"

        # Set output
        echo "highest-msrv=$highest_msrv" >> $GITHUB_OUTPUT