Clear cache for projects' licensed features in EE specs

This improves the overall experience with `stub_licensed_features`.

ee/spec/models/project_spec.rb

@@ -897,9 +897,11 @@ RSpec.describe Project do
 
     it 'only loads licensed availability once' do
       expect(project).to receive(:load_licensed_feature_available)
-                             .once.and_call_original
+        .once.and_call_original
 
-      2.times { project.feature_available?(:push_rules) }
+      with_license_feature_cache do
+        2.times { project.feature_available?(:push_rules) }
+      end
     end
 
     context 'when feature symbol is not included on Namespace features code' do

ee/spec/support/helpers/ee/license_helpers.rb

@@ -31,6 +31,13 @@ module EE
         end
       end
 
+      # Do not clear license feature cache in this block.
+      #
+      # Useful for specs which rely on caching license features.
+      def with_license_feature_cache(&block)
+        ClearLicensedFeatureAvailableCache.without_clear_cache(&block)
+      end
+
       def enable_namespace_license_check!
         stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
         ::Gitlab::CurrentSettings.update!(check_namespace_plan: true)
@@ -42,6 +49,35 @@ module EE
         gl_license = create(:gitlab_license, options)
         create(:license, data: gl_license.export)
       end
+
+      ::Project.prepend ClearLicensedFeatureAvailableCache
+    end
+
+    # This patch helps `stub_licensed_features` to work properly
+    # without the need of clearing caches manually in `before` blocks or
+    # using `let_it_be_refind` deliberately.
+    #
+    # See https://gitlab.com/gitlab-org/gitlab/-/issues/10385
+    module ClearLicensedFeatureAvailableCache
+      class << self
+        attr_accessor :clear_cache
+
+        def without_clear_cache
+          self.clear_cache = false
+          yield
+        ensure
+          self.clear_cache = true
+        end
+      end
+
+      # Enabled by default but can be disabled via `without_clear_cache`.
+      self.clear_cache = true
+
+      def licensed_feature_available?(*)
+        clear_memoization(:licensed_feature_available) if ClearLicensedFeatureAvailableCache.clear_cache
+
+        super
+      end
     end
   end
 end