ri-backward-compat.yml

name: RI Backward Compatibility

on:
  push:
    branches:
      - '**'
      - '!dependabot/**'
  pull_request:

permissions:
  contents: read

jobs:
  ri-backward-compat:
    name: RI reads data generated by RDoc ${{ matrix.old_rdoc }}
    strategy:
      fail-fast: false
      matrix:
        old_rdoc: ['6.5.0', '6.9.0', '7.0.2']
    runs-on: ubuntu-latest
    env:
      RI_DATA_DIR: /tmp/ri_data
    steps:
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
      - name: Set up Ruby
        uses: ruby/setup-ruby@26e5b7d197ebf60545ee9667bcbace0be11ccaec # v1.334.0
        with:
          # Must use Ruby 3.x — on Ruby 4.0, Heading is always a Class while old
          # RDoc versions serialized it as a Struct, so the test would always fail
          # regardless of whether the current code is correct.
          ruby-version: '3.4'
      - name: Generate ri data with old RDoc
        run: |
          gem install rdoc -v ${{ matrix.old_rdoc }} --no-document
          ruby -e '
            gem "rdoc", "${{ matrix.old_rdoc }}"
            require "rdoc/rdoc"
            puts "Generating ri data with RDoc #{RDoc::VERSION}"
            RDoc::RDoc.new.document(["--ri", "--op", ENV["RI_DATA_DIR"], "--quiet", "lib/"])
          '
      - name: Install current RDoc
        run: |
          gem build rdoc.gemspec
          gem install rdoc-*.gem --no-document
      - name: Verify current ri can read old data
        run: |
          ruby -e '
            require "rdoc"
            puts "Reading ri data with RDoc #{RDoc::VERSION}"

            store = RDoc::Store.new(RDoc::Options.new, path: ENV["RI_DATA_DIR"], type: :extra)
            store.load_cache

            modules = store.module_names
            errors = []

            modules.each do |mod_name|
              store.load_class(mod_name)
            rescue => e
              errors << [mod_name, e]
              warn "FAIL: #{mod_name} - #{e.class}: #{e.message}"
            end

            if errors.empty?
              puts "All #{modules.size} modules loaded successfully"
            else
              abort "#{errors.size} of #{modules.size} modules failed to load"
            end
          '