カバレッジ確認スクリプトで Claude Code への指示が快適になった話

namespace :coverage do
  desc '特定ファイルのカバレッジを表示（部分一致検索）'
  task :file, [:path] => :environment do |_t, args|
    require 'json'

    resultset_path = Rails.root.join('coverage/.resultset.json')

    unless File.exist?(resultset_path)
      puts 'Error: coverage/.resultset.json が見つかりません'
      puts 'bundle exec rspec を実行してカバレッジを生成してください'
      exit 1
    end

    resultset = JSON.parse(File.read(resultset_path))
    coverage = resultset.dig('RSpec', 'coverage')

    if coverage.nil?
      puts 'Error: カバレッジデータが見つかりません'
      exit 1
    end

    search_path = args[:path]
    if search_path.blank?
      puts 'Usage: bundle exec rake coverage:file[ファイルパスの一部]'
      puts '例: bundle exec rake coverage:file[commit]'
      exit 1
    end

    matches = coverage.select { |k, _| k.include?(search_path) }

    if matches.empty?
      puts "#{search_path} に一致するファイルが見つかりません"
      exit 0
    end

    matches.each do |file, data|
      lines = data['lines']
      relevant = lines.compact
      covered = relevant.count(&:positive?)
      pct = (covered.to_f / relevant.size * 100).round(2)
      relative_path = file.sub(Rails.root.join.to_s, '')

      puts "#{relative_path}: #{pct}% (#{covered}/#{relevant.size})"
    end
  end

  desc '全ファイルのカバレッジサマリーを表示'
  task summary: :environment do
    require 'json'

    resultset_path = Rails.root.join('coverage/.resultset.json')

    unless File.exist?(resultset_path)
      puts 'Error: coverage/.resultset.json が見つかりません'
      exit 1
    end

    resultset = JSON.parse(File.read(resultset_path))
    coverage = resultset.dig('RSpec', 'coverage')

    total_relevant = 0
    total_covered = 0

    coverage.each_value do |data|
      lines = data['lines']
      relevant = lines.compact
      total_relevant += relevant.size
      total_covered += relevant.count(&:positive?)
    end

    pct = (total_covered.to_f / total_relevant * 100).round(2)
    puts "全体カバレッジ: #{pct}% (#{total_covered}/#{total_relevant})"
  end

  desc 'カバレッジが100%未満のファイル一覧を表示'
  task incomplete: :environment do
    require 'json'

    resultset_path = Rails.root.join('coverage/.resultset.json')

    unless File.exist?(resultset_path)
      puts 'Error: coverage/.resultset.json が見つかりません'
      exit 1
    end

    resultset = JSON.parse(File.read(resultset_path))
    coverage = resultset.dig('RSpec', 'coverage')

    incomplete_files = []

    coverage.each do |file, data|
      lines = data['lines']
      relevant = lines.compact
      next if relevant.empty?

      covered = relevant.count(&:positive?)
      pct = (covered.to_f / relevant.size * 100).round(2)
      next if pct >= 100.0

      relative_path = file.sub(Rails.root.join.to_s, '')
      incomplete_files << { path: relative_path, pct: pct, covered: covered, total: relevant.size }
    end

    if incomplete_files.empty?
      puts '全てのファイルが100%カバーされています'
      exit 0
    end

    incomplete_files.sort_by! { |f| f[:pct] }

    incomplete_files.each do |f|
      puts "#{f[:path]}: #{f[:pct]}% (#{f[:covered]}/#{f[:total]})"
    end

    puts "\n合計: #{incomplete_files.size} ファイル"
  end
end