action.yml

---
# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions
name: Flatten Contexts
author: '@vbem'
description: Dump flattened GitHub contexts for friendly debugging
branding:
  icon: align-justify
  color: green

inputs:
  sep:
    description: 'Separator between key and value'
    required: false
    default: ''

# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#outputs-for-composite-actions
outputs: {}

# https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#runs-for-composite-actions
runs:
  using: composite
  steps:
    - name: Dump flattened GitHub actions contexts for debugging
      id: main
      env:
        STEP_CTX_GITHUB:    ${{ toJson(github) }}
        STEP_CTX_JOB:       ${{ toJson(job) }}
        STEP_CTX_STEPS:     ${{ toJson(steps) }}
        STEP_CTX_RUNNER:    ${{ toJson(runner) }}
        STEP_CTX_STRATEGY:  ${{ toJson(strategy) }}
        STEP_CTX_MATRIX:    ${{ toJson(matrix) }}
      shell: bash
      run: |
        # implementation details

        # Group stdin to stderr with title
        # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#grouping-log-lines
        #   $1: group title
        #   stdin: logs
        #   stderr: grouped logs
        #   $?: 0 if successful and non-zero otherwise
        function kit::wf::group {
            echo "::group::$1"      >&2
            echo "$(< /dev/stdin)"  >&2
            echo '::endgroup::'     >&2
        }

        # Flatten JSON to key-value lines
        #   $1: separator (default as ' 👉 ')
        #   stdin: json
        #   stdout: flattened key-value lines
        #   $?: 0 if successful and non-zero otherwise
        function kit::json::flatten {
            jq -Mcr --arg sep "${1:- 👉 }" \
            'paths(type!="object" and type!="array") as $p | {"key":$p|join("."),"value":getpath($p)} | "\(.key)\($sep)\(.value|@json)"'
        }

        # Render the context
        #   $1: context name
        #   stdin: json
        #   stderr: redered output
        #   $?: 0 if successful and non-zero otherwise
        function render {
            kit::json::flatten '${{ inputs.sep }}' | kit::wf::group "📚 GitHub context: '$1'"
        }

        jq -Mcre '{runner:.}' <<< "$STEP_CTX_RUNNER" | render "runner"
        jq -Mcre 'del(.token)|del(.event)|{github:.}' <<< "$STEP_CTX_GITHUB" | render "github"
        jq -Mcre '{github:{event:.event}}' <<< "$STEP_CTX_GITHUB" | render "github.event"
        jq -Mcre '{job:.}' <<< "$STEP_CTX_JOB" | render "job"
        jq -Mcre '{steps:.}' <<< "$STEP_CTX_STEPS" | render "steps"
        jq -Mcre '{strategy:.}' <<< "$STEP_CTX_STRATEGY" | render "strategy"
        jq -Mcre '{matrix:.}' <<< "$STEP_CTX_MATRIX" | render "matrix"
...