Simplify tests for test-unit support

The Rails application isn't cleaned up between tests so the test-unit
support was bleeding over into other tests. We don't have many tests
that depend on different Rails application state so I'm going with
deleting any created files after each test.

Fixes #22
Closes #32

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 2.3.0 / TBD
 
+* [ENHANCEMENT] Add support for test-unit
 * [ENHANCEMENT] Add support for Ruby 3.1+ and Rails 7.0+
 * [ENHANCEMENT] Drop support for EOL Ruby and Rails versions
 * [ENHANCEMENT] Change depdency from all of Rails to just railties

lib/generators/templates/test.erb

@@ -1,4 +1,4 @@
-require 'test_helper'
+require "test_helper"
 
 class <%= class_name %>Test < ActiveSupport::TestCase
   # test "the truth" do

spec/interactor/rails_spec.rb

@@ -204,9 +204,38 @@ class Invoice::PlaceOrder
             end
           end
         FILE
+      ensure
+        remove("spec/rails_helper.rb")
       end
     end
 
+    it "support test unit instead of rspec" do
+      # Enable test-unit support since it is skipped while generating the app.
+      write_file "config/initializers/test_unit.rb", <<~FILE
+        require "rails/test_unit/railtie"
+      FILE
+
+      run_command_and_stop "bundle exec rails generate interactor invoice/place_order"
+
+      path = "spec/interactors/invoice/place_order_spec.rb"
+      expect(path).not_to be_an_existing_file
+
+      path = "test/interactors/invoice/place_order_test.rb"
+      expect(path).to be_an_existing_file
+
+      expect(path).to have_file_content(<<~FILE)
+        require "test_helper"
+
+        class Invoice::PlaceOrderTest < ActiveSupport::TestCase
+          # test "the truth" do
+          #   assert true
+          # end
+        end
+      FILE
+    ensure
+      remove("config/initializers/test_unit.rb")
+    end
+
     it "auto-loads interactors" do
       run_command_and_stop "bundle exec rails generate interactor place_order"
       run_command_and_stop "bundle exec rails runner PlaceOrder"