Handle gracefully fixtures that only exist for tests in `TestHelper.u…

…nload_fixture` (#72)

TestHelper.unload_fixture: handle models without data

lib/frozen_record/test_helper.rb

@@ -12,7 +12,7 @@ def load_fixture(model_class, alternate_base_path)
 
         return if @cache.key?(model_class)
 
-        @cache[model_class] ||= model_class.base_path
+        @cache[model_class] = base_path_if_file_present(model_class)
 
         model_class.base_path = alternate_base_path
         model_class.load_records(force: true)
@@ -26,9 +26,10 @@ def unload_fixture(model_class)
         return unless @cache.key?(model_class)
 
         old_base_path = @cache[model_class]
-        model_class.base_path = old_base_path
-        model_class.load_records(force: true)
-
+        if old_base_path
+          model_class.base_path = old_base_path
+          model_class.load_records(force: true)
+        end
         @cache.delete(model_class)
       end
 
@@ -40,6 +41,19 @@ def unload_fixtures
 
       private
 
+      # Checks for the existence of the file for the frozen_record in the default directory.
+      # Returns the base_path if the file is present, otherwise nil.
+      # Some tests define specific test classes that do ONLY exist in the alternate directory.
+      # As `unload_fixture(s)` tries to force load the default file, it would raise an error for
+      # the "test only" fixtures. The nil value in the cache handles that case gracefully.
+      def base_path_if_file_present(model_class)
+        if File.exist?(model_class.file_path)
+          model_class.base_path
+        else
+          nil
+        end
+      end
+
       def ensure_model_class_is_frozenrecord(model_class)
         unless model_class < FrozenRecord::Base
           raise ArgumentError, "Model class (#{model_class}) does not inherit from #{FrozenRecord::Base}"

spec/fixtures/test_helper/only_in_tests.yml.erb

@@ -0,0 +1,3 @@
+---
+- id: 1
+  name: Some continent

spec/test_helper_spec.rb

@@ -49,6 +49,18 @@
       expect(Continent.count).to be == 1
       expect(Country.count).to be == 3
     end
+
+    context "when the test fixture does not exist in normal base path" do
+      class OnlyInTest < FrozenRecord::Base; end
+      before do
+        test_fixtures_base_path = File.join(File.dirname(__FILE__), 'fixtures', 'test_helper')
+        FrozenRecord::TestHelper.load_fixture(OnlyInTest, test_fixtures_base_path)
+      end
+      it 'unload fixture gracefully recovers from an ' do
+
+        expect { FrozenRecord::TestHelper.unload_fixture(OnlyInTest) }.not_to raise_error
+      end
+    end
   end
 
   describe '.unload_fixtures' do