ParameterType transformer runs in World

Gemfile.lock

@@ -4,7 +4,7 @@ PATH
     cucumber (3.0.2)
       builder (>= 2.1.2)
       cucumber-core (~> 3.0.0)
-      cucumber-expressions (~> 4.0.3)
+      cucumber-expressions (~> 5.0.3)
       cucumber-wire (~> 0.0.1)
       diff-lcs (~> 1.3)
       gherkin (~> 4.0)
@@ -25,7 +25,7 @@ GEM
     bcat (0.6.2)
       rack (~> 1.0)
     builder (3.2.3)
-    capybara (2.15.4)
+    capybara (2.16.1)
       addressable
       mini_mime (>= 0.1.3)
       nokogiri (>= 1.3.3)
@@ -39,7 +39,7 @@ GEM
       backports (>= 3.8.0)
       cucumber-tag_expressions (>= 1.0.1)
       gherkin (>= 4.1.3)
-    cucumber-expressions (4.0.4)
+    cucumber-expressions (5.0.3)
     cucumber-tag_expressions (1.0.1)
     cucumber-wire (0.0.1)
     diff-lcs (1.3)
@@ -64,18 +64,18 @@ GEM
     parser (2.4.0.2)
       ast (~> 2.3)
     powerpack (0.1.1)
-    pry (0.11.2)
+    pry (0.11.3)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (3.0.1)
     rack (1.6.8)
     rack-protection (1.5.3)
       rack
-    rack-test (0.7.0)
+    rack-test (0.8.2)
       rack (>= 1.0, < 3)
     rainbow (2.2.2)
       rake
-    rake (12.2.1)
+    rake (12.3.0)
     rspec (3.7.0)
       rspec-core (~> 3.7.0)
       rspec-expectations (~> 3.7.0)

cucumber.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'multi_json', '>= 1.7.5', '< 2.0'
   s.add_dependency 'multi_test', '>= 0.1.2'
   s.add_dependency 'cucumber-wire', '~> 0.0.1'
-  s.add_dependency 'cucumber-expressions', '~> 4.0.3'
+  s.add_dependency 'cucumber-expressions', '~> 5.0.3'
 
   s.add_development_dependency 'bundler', '~> 1.16.0'
   s.add_development_dependency 'aruba', '~> 0.6.1'

features/docs/writing_support_code/parameter_types.feature

@@ -52,18 +52,24 @@ Feature: Parameter Types
     When I run `cucumber features/foo.feature`
     Then it should pass
 
-    Scenario: Parameter type defined with ParameterType method
-      If your parameter type's `regexp` is very general, you can tell
-      Cucumber not to suggest its use in snippets:
-
+  Scenario: Parameter type delegating to World
     Given a file named "features/support/parameter_types.rb" with:
       """
       ParameterType(
         name: 'person',
         regexp: /[A-Z]\w+/,
-        transformer: -> (name) { Person.new(name) },
+        transformer: -> (name) { make_person(name) },
         use_for_snippets: false
       )
       """
+    Given a file named "features/support/world.rb" with:
+      """
+      module MyWorld
+        def make_person(name)
+          Person.new(name)
+        end
+      end
+      World(MyWorld)
+      """
     When I run `cucumber features/foo.feature`
     Then it should pass

lib/cucumber/glue/step_definition.rb

@@ -63,7 +63,7 @@ def parse_target_proc_from(options)
         end
       end
 
-      attr_reader :expression
+      attr_reader :expression, :registry
 
       def initialize(registry, expression, proc)
         raise 'No regexp' if expression.is_a?(Regexp)

lib/cucumber/step_match.rb

@@ -13,7 +13,10 @@ def initialize(step_definition, step_name, step_arguments)
     end
 
     def args
-      @step_arguments.map(&:value)
+      current_world = @step_definition.registry.current_world
+      @step_arguments.map do |arg|
+        arg.value(current_world)
+      end
     end
 
     def activate(test_step)