Move sample values to group instance

The goal is to construct examples with a parameterless initializer.
This doesn't quite work, since the sample values are retrieved via the
harness, which doesn't have an active example when the sample values are
created.

src/spectator.cr

@@ -41,12 +41,6 @@ module Spectator
       include ::Spectator::DSL::StructureDSL # Include the DSL for creating groups, example, and more.
       include ::Spectator::DSL::ExampleDSL   # Mix in methods and macros specifically for example DSL.
 
-      # Placeholder initializer.
-      # This is needed because examples and groups call super in their initializer.
-      # Those initializers pass the sample values upward through their hierarchy.
-      def initialize(_sample_values : ::Spectator::Internals::SampleValues)
-      end
-
       # Pass off the "what" argument and block to `DSL::StructureDSL.describe`.
       # That method will handle creating a new group for this spec.
       describe({{what}}) {{block}}

src/spectator/dsl/example_factory.cr

@@ -7,9 +7,9 @@ module Spectator::DSL
     end
 
     # Constructs a new example instance and returns it.
-    # The *group* and *sample_values* are passed to `Example#initialize`.
+    # The *group* is passed to `Example#initialize`.
-    def build(group : ExampleGroup, sample_values : Internals::SampleValues) : Example
+    def build(group : ExampleGroup, _sample_values : Internals::SampleValues) : Example
-      @example_type.new(group, sample_values)
+      @example_type.new(group)
     end
   end
 end

src/spectator/dsl/nested_example_group_builder.cr

@@ -26,7 +26,7 @@ module Spectator::DSL
     # The *parent* should be the group that contains this group.
     # The *sample_values* will be given to all of the examples (and groups) nested in this group.
     def build(parent : ExampleGroup, sample_values : Internals::SampleValues) : NestedExampleGroup
-      NestedExampleGroup.new(@what, parent, hooks, conditions).tap do |group|
+      NestedExampleGroup.new(@what, parent, hooks, conditions, sample_values).tap do |group|
         # Set the group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/root_example_group_builder.cr

@@ -6,7 +6,7 @@ module Spectator::DSL
     # Creates a `RootExampleGroup` which can have instances of `Example` and `ExampleGroup` nested in it.
     # The *sample_values* will be given to all of the examples (and groups) nested in this group.
     def build(sample_values : Internals::SampleValues) : RootExampleGroup
-      RootExampleGroup.new(hooks, conditions).tap do |group|
+      RootExampleGroup.new(hooks, conditions, sample_values).tap do |group|
         # Set the group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/sample_example_group_builder.cr

@@ -39,11 +39,11 @@ module Spectator::DSL
     # The *parent* should be the group that contains this group.
     # The *sample_values* will be given to all of the examples (and groups) nested in this group.
     def build(parent : ExampleGroup, sample_values : Internals::SampleValues) : NestedExampleGroup
-      collection = @collection_builder.call(@collection_type.new(sample_values))
+      collection = @collection_builder.call(@collection_type.new)
 
       # This creates the container for the sub-groups.
       # The hooks are defined here, instead of repeating for each sub-group.
-      NestedExampleGroup.new(@what, parent, hooks, conditions).tap do |group|
+      NestedExampleGroup.new(@what, parent, hooks, conditions, sample_values).tap do |group|
         # Set the container group's children to be sub-groups for each item in the collection.
         group.children = collection.map do |value|
           # Create a sub-group for each item in the collection.
@@ -61,7 +61,7 @@ module Spectator::DSL
     private def build_sub_group(parent : ExampleGroup, sample_values : Internals::SampleValues, value : T) : NestedExampleGroup
       # Add the value to sample values for this sub-group.
       sub_values = sample_values.add(@symbol, @name, value)
-      NestedExampleGroup.new(value.to_s, parent, ExampleHooks.empty, ExampleConditions.empty).tap do |group|
+      NestedExampleGroup.new(value.to_s, parent, ExampleHooks.empty, ExampleConditions.empty, sub_values).tap do |group|
         # Set the sub-group's children to built versions of the children from this instance.
         group.children = @children.map do |child|
           # Build the child and up-cast to prevent type errors.

src/spectator/dsl/structure_dsl.cr

@@ -503,13 +503,6 @@ module Spectator::DSL
       # The collection could reference a helper method
       # or anything else in the parent scope.
       class Sample%sample < {{@type.id}}
-        # Placeholder initializer.
-        # This is needed because examples and groups call super in their initializer.
-        # Those initializers pass the sample values upward through their hierarchy.
-        def initialize(_sample_values : ::Spectator::Internals::SampleValues)
-          super
-        end
-
         # Method that returns an array containing the collection.
         # This method should be called only once.
         # The framework stores the collection as an array for a couple of reasons.
@@ -543,9 +536,9 @@ module Spectator::DSL
         end
 
         # Initializer to extract current element of the collection from sample values.
-        def initialize(sample_values : ::Spectator::Internals::SampleValues)
+        def initialize
           super
-          @%wrapper = sample_values.get_wrapper(:%sample)
+          @%wrapper = ::Spectator::Internals::Harness.current.group.sample_values.get_wrapper(:%sample)
         end
 
         # Start a new example group.
@@ -656,9 +649,9 @@ module Spectator::DSL
         end
 
         # Initializer to extract current element of the collection from sample values.
-        def initialize(sample_values : ::Spectator::Internals::SampleValues)
+        def initialize
           super
-          @%wrapper = sample_values.get_wrapper(:%sample)
+          @%wrapper = ::Spectator::Internals::Harness.current.group.sample_values.get_wrapper(:%sample)
         end
 
         # Start a new example group.
@@ -1576,13 +1569,6 @@ module Spectator::DSL
     private macro _spectator_test(class_name, run_method_name)
       # Wrapper class for isolating the test code.
       class {{class_name.id}} < {{@type.id}}
-        # Initializer that accepts sample values.
-        # The sample values are passed upward to the group modules.
-        # Any module that adds sample values can pull their values from this instance.
-        def initialize(sample_values : ::Spectator::Internals::SampleValues)
-          super
-        end
-
         # Generated method for actually running the test code.
         def {{run_method_name.id}}
           {{yield}}
@@ -1614,9 +1600,9 @@ module Spectator::DSL
         # Stores the group the example belongs to
         # and sample values specific to this instance of the test.
         # This method's signature must match the one used in `ExampleFactory#build`.
-        def initialize(group : ::Spectator::ExampleGroup, sample_values : ::Spectator::Internals::SampleValues)
+        def initialize(group : ::Spectator::ExampleGroup)
           super
-          @instance = {{test_class_name.id}}.new(sample_values)
+          @instance = {{test_class_name.id}}.new
         end
 
         # Retrieves the underlying, wrapped test code.

src/spectator/example.cr

@@ -31,8 +31,7 @@ module Spectator
 
     # Creates the base of the example.
     # The group should be the example group the example belongs to.
-    # The *sample_values* are passed to the example code.
+    def initialize(@group)
-    def initialize(@group, sample_values : Internals::SampleValues)
     end
 
     # Indicates there is only one example to run.

src/spectator/example_group.cr

@@ -15,9 +15,11 @@ module Spectator
     include Enumerable(ExampleComponent)
     include Iterable(ExampleComponent)
 
+    getter sample_values : Internals::SampleValues
+
     # Creates the example group.
     # The hooks are stored to be triggered later.
-    def initialize(@hooks : ExampleHooks, @conditions : ExampleConditions)
+    def initialize(@hooks : ExampleHooks, @conditions : ExampleConditions, @sample_values)
       @before_all_hooks_run = false
       @after_all_hooks_run = false
     end

src/spectator/internals/harness.cr

@@ -34,6 +34,11 @@ module Spectator::Internals
     # Retrieves the current running example.
     getter example : Example
 
+    # Retrieves the group for the current running example.
+    def group
+      example.group
+    end
+
     # Reports the outcome of an expectation.
     # An exception will be raised when a failing result is given.
     def report_expectation(expectation : Expectations::Expectation) : Nil

src/spectator/nested_example_group.cr

@@ -18,8 +18,8 @@ module Spectator
     # The parent's children must contain this group,
     # otherwise there may be unexpected behavior.
     # The *hooks* are stored to be triggered later.
-    def initialize(@what, @parent, hooks : ExampleHooks, conditions : ExampleConditions)
+    def initialize(@what, @parent, hooks : ExampleHooks, conditions : ExampleConditions, sample_values)
-      super(hooks, conditions)
+      super(hooks, conditions, sample_values)
     end
 
     # Indicates wheter the group references a type.