1 files changed, 74 insertions, 0 deletions
diff --git a/actionpack/test/journey/nfa/transition_table_test.rb b/actionpack/test/journey/nfa/transition_table_test.rb
new file mode 100644
index 0000000000..c23611e980
--- /dev/null
+++ b/actionpack/test/journey/nfa/transition_table_test.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+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