action.yaml

name: "Validate OpenAPI spec against TOMP-API"
description: "Compare a candidate OpenAPI spec against the TOMP-API reference and fail the build on breaking changes."
author: "Bas Matthee <basmatthee@gmail.com>"
inputs:
  candidate_spec:
    description: "Path to your OpenAPI YAML file (relative to workspace)"
    required: true
  version_tag:
    description: "TOMP-API release tag (e.g., v1.6.1). Defaults to latest."
    required: false
  fail_on_breaking_changes:
    description: "Fail if breaking changes are found"
    required: false
    default: "true"
  fail_on_non_breaking_changes:
    description: "Fail if non-breaking changes are found"
    required: false
    default: "false"
  show_unclassified:
    description: "Show unclassified changes"
    required: false
    default: "true"

runs:
  using: "composite"
  steps:
    - name: Prepare working directory
      run: |
        export DIFFDIR="/tmp/openapi-diff"
        echo "DIFFDIR=$DIFFDIR" >> "$GITHUB_ENV"
        mkdir -p "$DIFFDIR"
        cp "${{ github.workspace }}/${{ inputs.candidate_spec }}" "$DIFFDIR/openapi.yaml"
      shell: bash

    - name: Fetch TOMP-API reference spec
      run: |
        VERSION="${{ inputs.version_tag }}"
        if [[ -z "$VERSION" ]]; then
          VERSION=$(curl -s https://api.github.com/repos/TOMP-WG/TOMP-API/releases/latest | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/')
        fi

        echo "📦 Using TOMP-API version: $VERSION"
        curl -fsSL "https://raw.githubusercontent.com/TOMP-WG/TOMP-API/$VERSION/TOMP-API.yaml" \
          -o "/tmp/openapi-diff/TOMP-API-reference.yaml"

        chmod a+r /tmp/openapi-diff/*.yaml
      shell: bash

    - name: Bundle specs with Redocly
      run: |
        npm install --no-fund --no-audit --loglevel=error -g @redocly/cli 
        redocly bundle /tmp/openapi-diff/openapi.yaml -o /tmp/openapi-diff/openapi-bundled.yaml > /dev/null
        redocly bundle /tmp/openapi-diff/TOMP-API-reference.yaml -o /tmp/openapi-diff/TOMP-API-reference-bundled.yaml > /dev/null
      shell: bash

    - name: Run openapi-diff
      run: |
        echo "🧪 Running openapi-diff..."

        docker_output=$(mktemp)
        docker run --rm \
          -v /tmp/openapi-diff:/specs \
          openapitools/openapi-diff:latest \
          /specs/TOMP-API-reference-bundled.yaml /specs/openapi-bundled.yaml \
          > /tmp/openapi-diff/diff_result.txt 2>"$docker_output" || {
            echo "exit_code=$?" >> "$GITHUB_OUTPUT"
          }

        echo "🧪 Diff Result:"
        cat /tmp/openapi-diff/diff_result.txt
      shell: bash

    - name: Fail on configured diff results
      run: |
        RESULT=$(cat /tmp/openapi-diff/diff_result.txt)
        FAIL=false

        if [[ "$RESULT" == *"API changes broke backward compatibility"* && "${{ inputs.fail_on_breaking_changes }}" == "true" ]]; then
          echo "❌ Breaking changes detected!"
          FAIL=true
        fi

        if [[ "$RESULT" == *"API changes are backward compatible"* && "${{ inputs.fail_on_non_breaking_changes }}" == "true" ]]; then
          echo "⚠️ Non-breaking changes present!"
          FAIL=true
        fi

        if [[ "$RESULT" == *"UNCLASSIFIED"* && "${{ inputs.show_unclassified }}" == "true" ]]; then
          echo "❓ Unclassified changes detected:"
          echo "$RESULT" | grep UNCLASSIFIED
        fi

        if [[ "$FAIL" == "true" ]]; then
          echo "💥 Spec comparison failed based on your config."
          exit 1
        else
          echo "✅ Spec comparison passed."
        fi
      shell: bash