require "minitest"

module Lox
  class Test < Minitest::Test
    LOX_BIN = File.expand_path("../bin/lox", __dir__)

    def assert_lox(path)
      src = File.read(path)

      expected_out = src.scan(/(?<=\/\/ expect: )(?~\n)/).join("\n")

      out, _err, _status = Open3.capture3(LOX_BIN, path)

      assert_equal expected_out, out
    end
  end

  book_src = File.expand_path(ENV.fetch("CRAFTING_INTERPRETERS_SRC"))
  Dir.chdir(book_src) do
    lox_tests = Dir["./test/**/*.lox"]
      .group_by {|path| path.rpartition(?/).first.sub(/\.\/test\/?/, "") }

    lox_tests.each do |dir, paths|
      klass = Class.new(Test) do
        paths.each do |path|
          name = File.basename(path, ".lox")
          define_method("test_#{name}") do
            assert_lox File.expand_path(path, book_src)
          end
        end
      end

      suite = dir.split(?/).map(&:capitalize).join
      suite = "Root" if suite.empty?
      Object.const_set("Test#{suite}", klass)
    end
  end
end