require 'abstract_unit'

module ActionDispatch
  module Journey
    module NFA
      class TestTransitionTable < ActiveSupport::TestCase
        def setup
          @parser = Journey::Parser.new
        end

        def test_eclosure
          table = tt '/'
          assert_equal [0], table.eclosure(0)

          table = tt ':a|:b'
          assert_equal 3, table.eclosure(0).length

          table = tt '(:a|:b)'
          assert_equal 5, table.eclosure(0).length
          assert_equal 5, table.eclosure([0]).length
        end

        def test_following_states_one
          table = tt '/'

          assert_equal [1], table.following_states(0, '/')
          assert_equal [1], table.following_states([0], '/')
        end

        def test_following_states_group
          table  = tt 'a|b'
          states = table.eclosure 0

          assert_equal 1, table.following_states(states, 'a').length
          assert_equal 1, table.following_states(states, 'b').length
        end

        def test_following_states_multi
          table  = tt 'a|a'
          states = table.eclosure 0

          assert_equal 2, table.following_states(states, 'a').length
          assert_equal 0, table.following_states(states, 'b').length
        end

        def test_following_states_regexp
          table  = tt 'a|:a'
          states = table.eclosure 0

          assert_equal 1, table.following_states(states, 'a').length
          assert_equal 1, table.following_states(states, /[^\.\/\?]+/).length
          assert_equal 0, table.following_states(states, 'b').length
        end

        def test_alphabet
          table  = tt 'a|:a'
          assert_equal [/[^\.\/\?]+/, 'a'], table.alphabet

          table  = tt 'a|a'
          assert_equal ['a'], table.alphabet
        end

        private
        def tt string
          ast     = @parser.parse string
          builder = Builder.new ast
          builder.transition_table
        end
      end
    end
  end
end