Improve our SafeDup module

Include Refiment for True, False, Integer and Float classes
to be able to call #dup on ruby 2.1

The method frozen_or_dup for ruby 2.3 an oward only epxect to receive
String values. by checking if the value we can warranty same behavior
for all kind of objects

lib/datadog/core/utils/safe_dup.rb

@@ -13,20 +13,70 @@ def dup
             end
           end
 
+          # Ensures #initialize can call true.dup safely
+          module RefineTrue
+            refine TrueClass do
+              def dup
+                self
+              end
+            end
+          end
+
+          # Ensures #initialize can call false.dup safely
+          module RefineFalse
+            refine FalseClass do
+              def dup
+                self
+              end
+            end
+          end
+
+          # Ensures #initialize can call 1.dup safely
+          module RefineInteger
+            refine Integer do
+              def dup
+                self
+              end
+            end
+          end
+
+          # Ensures #initialize can call 1.0.dup safely
+          module RefineFloat
+            refine Float do
+              def dup
+                self
+              end
+            end
+          end
+
           using RefineNil
+          using RefineTrue
+          using RefineFalse
+          using RefineInteger
+          using RefineFloat
         end
 
         # String#+@ was introduced in Ruby 2.3
         if String.method_defined?(:+@) && String.method_defined?(:-@)
           def self.frozen_or_dup(v)
-            # If the string is not frozen, the +(-v) will:
-            # - first create a frozen deduplicated copy with -v
-            # - then it will dup it more efficiently with +v
-            v.frozen? ? v : +(-v)
+            case v
+            when String
+              # If the string is not frozen, the +(-v) will:
+              # - first create a frozen deduplicated copy with -v
+              # - then it will dup it more efficiently with +v
+              v.frozen? ? v : +(-v)
+            else
+              v.frozen? ? v : v.dup
+            end
           end
 
           def self.frozen_dup(v)
-            -v if v
+            case v
+            when String
+              -v if v
+            else
+              v.frozen? ? v : v.dup.freeze
+            end
           end
         else
           def self.frozen_or_dup(v)

spec/datadog/core/utils/safe_dup_spec.rb

@@ -1,62 +1,260 @@
 require 'datadog/core/utils/safe_dup'
 
 RSpec.describe Datadog::Core::Utils::SafeDup do
-  describe '.frozen_or_dup' do
-    context 'when given a frozen string' do
-      it 'returns the original input' do
-        input = 'a_frozen_string'.freeze
+  context 'String' do
+    describe '.frozen_or_dup' do
+      context 'when given a frozen string' do
+        it 'returns the original input' do
+          input = 'a_frozen_string'.freeze
 
-        result = described_class.frozen_or_dup(input)
+          result = described_class.frozen_or_dup(input)
 
-        expect(input).to be_frozen
+          expect(input).to be_frozen
 
-        expect(result).to eq(input)
-        expect(result).to be(input)
-        expect(result).to be_frozen
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a string' do
+        it 'returns a non frozen dupliacte' do
+          input = 'a_string'
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).not_to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).not_to be_frozen
+        end
+      end
+    end
+
+    describe '.frozen_dup' do
+      context 'when given a frozen string' do
+        it 'returns the original input' do
+          input = 'a_frozen_string'.freeze
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a string' do
+        it 'returns a frozen duplicate' do
+          input = 'a_string'
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).not_to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).to be_frozen
+        end
+      end
+    end
+  end
+
+  context 'Hash' do
+    describe '.frozen_or_dup' do
+      context 'when given a frozen hash' do
+        it 'returns the original input' do
+          input = { a: :b }.freeze
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a hash' do
+        it 'returns a non frozen dupliacte' do
+          input = { a: :b }
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).not_to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).not_to be_frozen
+        end
       end
     end
 
-    context 'when given a string' do
-      it 'returns a non frozen dupliacte' do
-        input = 'a_string'
+    describe '.frozen_dup' do
+      context 'when given a frozen hash' do
+        it 'returns the original input' do
+          input = { a: :b }.freeze
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a hash' do
+        it 'returns a frozen duplicate' do
+          input = { a: :b }
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).not_to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).to be_frozen
+        end
+      end
+    end
+  end
+
+  context 'Boolean' do
+    before do
+      skip 'TrueClass and FalseClass are not frozen by default on ruby 2.1' if RUBY_VERSION < '2.2'
+    end
+
+    describe '.frozen_or_dup' do
+      context 'when given a boolean' do
+        it 'returns the original input' do
+          input = true
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+    end
+
+    describe '.frozen_dup' do
+      context 'when given a boolean' do
+        it 'returns the original input' do
+          input = true
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+    end
+  end
+
+  context 'Array' do
+    describe '.frozen_or_dup' do
+      context 'when given a frozen array' do
+        it 'returns the original input' do
+          input = [1].freeze
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a string' do
+        it 'returns a non frozen array' do
+          input = [1]
+
+          result = described_class.frozen_or_dup(input)
+
+          expect(input).not_to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).not_to be_frozen
+        end
+      end
+    end
+
+    describe '.frozen_dup' do
+      context 'when given a frozen array' do
+        it 'returns the original input' do
+          input = [1].freeze
+
+          result = described_class.frozen_dup(input)
+
+          expect(input).to be_frozen
+
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
+      end
+
+      context 'when given a array' do
+        it 'returns a frozen duplicate' do
+          input = [1]
 
-        result = described_class.frozen_or_dup(input)
+          result = described_class.frozen_dup(input)
 
-        expect(input).not_to be_frozen
+          expect(input).not_to be_frozen
 
-        expect(result).to eq(input)
-        expect(result).not_to be(input)
-        expect(result).not_to be_frozen
+          expect(result).to eq(input)
+          expect(result).not_to be(input)
+          expect(result).to be_frozen
+        end
       end
     end
   end
 
-  describe '.frozen_dup' do
-    context 'when given a frozen string' do
-      it 'returns the original input' do
-        input = 'a_frozen_string'.freeze
+  context 'Numeric' do
+    describe '.frozen_or_dup' do
+      context 'when given a numeric' do
+        it 'returns the original input' do
+          input = 1
 
-        result = described_class.frozen_dup(input)
+          result = described_class.frozen_or_dup(input)
 
-        expect(input).to be_frozen
+          expect(input).to be_frozen
 
-        expect(result).to eq(input)
-        expect(result).to be(input)
-        expect(result).to be_frozen
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
       end
     end
 
-    context 'when given a string' do
-      it 'returns a frozen duplicate' do
-        input = 'a_string'
+    describe '.frozen_dup' do
+      context 'when given a numeric' do
+        it 'returns the original input' do
+          input = 10.0
 
-        result = described_class.frozen_dup(input)
+          result = described_class.frozen_dup(input)
 
-        expect(input).not_to be_frozen
+          expect(input).to be_frozen
 
-        expect(result).to eq(input)
-        expect(result).not_to be(input)
-        expect(result).to be_frozen
+          expect(result).to eq(input)
+          expect(result).to be(input)
+          expect(result).to be_frozen
+        end
       end
     end
   end