diff --git a/lib/generator/case_values.rb b/lib/generator/case_values.rb
index 9d109d9edc..d025fbc2a8 100644
--- a/lib/generator/case_values.rb
+++ b/lib/generator/case_values.rb
@@ -1,39 +1,24 @@
 module Generator
   module CaseValues
-
     class Extractor
-      attr_reader :exercise_name, :exercise_data
-
-      def self.extract(exercise_name:, exercise_data:)
-        self.new(
-          exercise_name: exercise_name,
-          exercise_data: exercise_data
-        ).extract
-      end
-
-      def initialize(exercise_name:, exercise_data:)
-        @exercise_name = exercise_name
-        @exercise_data = exercise_data
+      def initialize(case_class:)
+        @case_class = case_class
       end
 
-      def extract
-        extract_test_cases.map.with_index do |test, index|
-          test_case_class.new(test.merge('index' => index))
+      def call(exercise_data)
+        parsed_data = JSON.parse(exercise_data)['cases']
+        extract_test_cases(data: parsed_data).map.with_index do |test, index|
+          @case_class.new(test.merge('index' => index))
         end
       end
 
       private
 
-      def extract_test_cases(data: JSON.parse(exercise_data)['cases'])
+      def extract_test_cases(data:)
         data.flat_map do |entry|
           entry.key?('cases') ? extract_test_cases(data: entry['cases']) : entry
         end
       end
-
-      def test_case_class
-        Object.const_get(Files::GeneratorCases.class_name(exercise_name))
-      end
     end
-
   end
 end
diff --git a/lib/generator/template_values.rb b/lib/generator/template_values.rb
index b4dceeaa63..700d8c585b 100644
--- a/lib/generator/template_values.rb
+++ b/lib/generator/template_values.rb
@@ -27,11 +27,13 @@ def template_values
 
     def extract
       load cases_load_name
+      extractor.call(canonical_data.to_s)
+    end
 
-      CaseValues::Extractor.extract(
-        exercise_name: exercise_name,
-        exercise_data: canonical_data.to_s
-      )
+    def extractor
+        CaseValues::Extractor.new(
+          case_class: Object.const_get(Files::GeneratorCases.class_name(exercise_name))
+        )
     end
 
     def cases_load_name
diff --git a/test/generator/case_values_test.rb b/test/generator/case_values_test.rb
index 7f57e8f80a..4560cfd048 100644
--- a/test/generator/case_values_test.rb
+++ b/test/generator/case_values_test.rb
@@ -10,10 +10,10 @@ module Generator
   module CaseValues
     class ExtractorTest < Minitest::Test
       def test_multi_level_auto_extraction
+        canonical_data = File.read('test/fixtures/metadata/exercises/complex/canonical-data.json')
         cases = Extractor.new(
-          exercise_name: 'complex',
-          exercise_data: File.read('test/fixtures/metadata/exercises/complex/canonical-data.json')
-        ).extract
+          case_class: ComplexCase,
+        ).call(canonical_data)
 
         expected = [
           ComplexCase.new(description: 'first generic verse', property: 'verse', number: 99,