feat(internals): add cache to class

lib/convenient_service/common/plugins/has_internals/entities/internals/plugins/has_cache/concern.rb

@@ -15,6 +15,18 @@ module HasCache
                 module Concern
                   include Support::Concern
 
+                  class_methods do
+                    ##
+                    # @return [ConvenientService::Support::Cache]
+                    #
+                    # @internal
+                    #   TODO: `Support::Cache.create(backend: :thread_safe_hash)`.
+                    #
+                    def cache
+                      @cache ||= Support::Cache.create(backend: :hash)
+                    end
+                  end
+
                   instance_methods do
                     ##
                     # @return [ConvenientService::Support::Cache]

spec/lib/convenient_service/common/plugins/has_internals/entities/internals/plugins/has_cache/concern_spec.rb

@@ -5,6 +5,16 @@
 require "convenient_service"
 
 RSpec.describe ConvenientService::Common::Plugins::HasInternals::Entities::Internals::Plugins::HasCache::Concern do
+  let(:internals_class) do
+    Class.new.tap do |klass|
+      klass.class_exec(described_class) do |mod|
+        include mod
+      end
+    end
+  end
+
+  let(:internals_instance) { internals_class.new }
+
   example_group "modules" do
     include ConvenientService::RSpec::Matchers::IncludeModule
 
@@ -15,15 +25,45 @@
     context "when included" do
       subject { internals_class }
 
-      let(:internals_class) do
-        Class.new.tap do |klass|
-          klass.class_exec(described_class) do |mod|
-            include mod
-          end
-        end
+      it { is_expected.to include_module(described_class::InstanceMethods) }
+    end
+  end
+
+  example_group "class methods" do
+    include ConvenientService::RSpec::Matchers::DelegateTo
+    include ConvenientService::RSpec::PrimitiveMatchers::CacheItsValue
+
+    describe ".cache" do
+      specify do
+        expect { internals_class.cache }
+          .to delegate_to(ConvenientService::Support::Cache, :create)
+          .with_arguments(backend: :hash)
+          .and_return_its_value
       end
 
-      it { is_expected.to include_module(described_class::InstanceMethods) }
+      specify do
+        expect { internals_class.cache }.to cache_its_value
+      end
+    end
+  end
+
+  example_group "instance methods" do
+    include ConvenientService::RSpec::Matchers::DelegateTo
+    include ConvenientService::RSpec::PrimitiveMatchers::CacheItsValue
+
+    describe "#cache" do
+      let(:internals) { internals_instance }
+
+      specify do
+        expect { internals.cache }
+          .to delegate_to(ConvenientService::Support::Cache, :create)
+          .with_arguments(backend: :hash)
+          .and_return_its_value
+      end
+
+      specify do
+        expect { internals.cache }.to cache_its_value
+      end
     end
   end
 end