Change to memoize empty decorator chain

piotrmurach · Jun 28, 2020 · 79b50ce · 79b50ce
1 parent 60e7012
commit 79b50ce
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 3 deletions.
diff --git a/lib/pastel/decorator_chain.rb b/lib/pastel/decorator_chain.rb
@@ -13,13 +13,13 @@ class DecoratorChain
     #
     # @api public
     def self.empty
-      new
+      @empty ||= self.new
     end
 
     # Create a decorator chain
     #
     # @api public
-    def initialize(decorators = [])
+    def initialize(decorators = [].freeze)
       @decorators = decorators
     end
 

diff --git a/spec/unit/decorator_chain_spec.rb b/spec/unit/decorator_chain_spec.rb
@@ -5,7 +5,13 @@
     expect(described_class.new).to be_a(Enumerable)
   end
 
-  describe ".each" do
+  describe ".empty" do
+    it "memoizes an empty chain" do
+      expect(described_class.empty.object_id).to eq(described_class.empty.object_id)
+    end
+  end
+
+  describe "#each" do
     it "yields each decorator" do
       first   = double("first")
       second  = double("second")