Use generic test framework for independent matchers test

spec/acceptance/independent_matchers_spec.rb

@@ -2,14 +2,14 @@ require 'acceptance_spec_helper'
 
 describe 'shoulda-matchers has independent matchers' do
   context 'specifically delegate_method' do
-    specify 'and integrates with a Ruby application that uses Minitest' do
+    specify 'and integrates with a Ruby application that uses the default test framework' do
       create_generic_bundler_project
 
       updating_bundle do
         add_minitest_to_project
         add_shoulda_context_to_project(manually: true)
         add_shoulda_matchers_to_project(
-          test_frameworks: [:minitest],
+          test_frameworks: [default_test_framework],
           manually: true
         )
       end
@@ -35,11 +35,11 @@ describe 'shoulda-matchers has independent matchers' do
         end
       FILE
 
-      write_minitest_test 'test/courier_test.rb' do |test_case_superclass|
+      write_n_unit_test 'test/courier_test.rb' do |test_case_superclass|
         <<-FILE
-          require "test_helper"
-          require "courier"
-          require "post_office"
+          require 'test_helper'
+          require 'courier'
+          require 'post_office'
 
           class CourierTest < #{test_case_superclass}
             subject { Courier.new(post_office) }

spec/support/acceptance/helpers/minitest_helpers.rb

@@ -4,14 +4,6 @@ module AcceptanceTests
   module MinitestHelpers
     include GemHelpers
 
-    def minitest_test_case_superclass
-      if minitest_version >= 5
-        'Minitest::Test'
-      else
-        'MiniTest::Unit::TestCase'
-      end
-    end
-
     def minitest_version
       bundle_version_of('minitest')
     end

spec/support/acceptance/helpers/n_unit_helpers.rb

@@ -4,6 +4,14 @@ module AcceptanceTests
   module NUnitHelpers
     include RailsVersionHelpers
 
+    def n_unit_test_case_superclass
+      case default_test_framework
+        when :test_unit then 'Test::Unit::TestCase'
+        when :minitest_4 then 'MiniTest::Unit::TestCase'
+        else 'Minitest::Test'
+      end
+    end
+
     def default_test_framework
       if rails_version =~ '< 4'
         :test_unit

spec/support/acceptance/helpers/step_helpers.rb

@@ -45,8 +45,8 @@ module AcceptanceTests
       end
     end
 
-    def write_minitest_test(path)
-      contents = yield minitest_test_case_superclass
+    def write_n_unit_test(path)
+      contents = yield n_unit_test_case_superclass
       write_file(path, contents)
     end