Add .memoized? method

To check (externally) if method memoized or not.

lib/memery.rb

@@ -31,6 +31,13 @@ def memoize(method_name, condition: nil, ttl: nil)
       define_memoized_method!(method_name, condition: condition, ttl: ttl)
     end
 
+    def memoized?(method_name)
+      return faslse unless defined?(@_memery_module)
+
+      @_memery_module.method_defined?(method_name) ||
+        @_memery_module.private_method_defined?(method_name)
+    end
+
     private
 
     def prepend_memery_module!

spec/memery_spec.rb

@@ -14,6 +14,8 @@ class A
     m_private
   end
 
+  def not_memoized; end
+
   memoize def m_nil
     m_protected
   end
@@ -254,4 +256,38 @@ class E
       end
     end
   end
+
+  describe ".memoized?" do
+    subject { A.memoized?(method_name) }
+
+    context "public memoized method" do
+      let(:method_name) { :m }
+
+      it { is_expected.to be true }
+    end
+
+    context "private memoized method" do
+      let(:method_name) { :m_private }
+
+      it { is_expected.to be true }
+    end
+
+    context "non-memoized method" do
+      let(:method_name) { :not_memoized }
+
+      it { is_expected.to be false }
+    end
+
+    context "standard class method" do
+      let(:method_name) { :constants }
+
+      it { is_expected.to be false }
+    end
+
+    context "standard instance method" do
+      let(:method_name) { :to_s }
+
+      it { is_expected.to be false }
+    end
+  end
 end