MONGOID-5257 make === equivalent to == (#5172)

* MONGOID-5257 make === equivalent to ==

* MONGOID-5257 move class === to equality

* MONGOID-5257 test all === tests with feature flag turned on and off

Author: neilshweky

lib/mongoid/document.rb

@@ -272,22 +272,6 @@ def as_attributes
 
     module ClassMethods
 
-      # Performs class equality checking.
-      #
-      # @example Compare the classes.
-      #   document === other
-      #
-      # @param [ Document, Object ] other The other object to compare with.
-      #
-      # @return [ true, false ] True if the classes are equal, false if not.
-      def ===(other)
-        if Mongoid.legacy_triple_equals
-          other.class == Class ? self <= other : other.is_a?(self)
-        else
-          other.is_a?(self)
-        end
-      end
-
       # Instantiate a new object, only when loaded from the database or when
       # the attributes have already been typecast.
       #

lib/mongoid/equality.rb

@@ -4,6 +4,9 @@ module Mongoid
 
   # This module contains the behavior of Mongoid's clone/dup of documents.
   module Equality
+    # Leave the current contents of this module outside of InstanceMethods
+    # to prevent cherry picking conflicts. For now...
+    extend ActiveSupport::Concern
 
     # Default comparison is via the string version of the id.
     #
@@ -40,7 +43,11 @@ def ==(other)
     #
     # @return [ true, false ] True if the classes are equal, false if not.
     def ===(other)
-      other.class == Class ? self.class === other : self == other
+      if Mongoid.legacy_triple_equals
+        super
+      else
+        other.class == Class ? self.class === other : self == other
+      end
     end
 
     # Delegates to ==. Used when needing checks in hashes.
@@ -54,5 +61,23 @@ def ===(other)
     def eql?(other)
       self == (other)
     end
+
+    module ClassMethods
+      # Performs class equality checking.
+      #
+      # @example Compare the classes.
+      #   document === other
+      #
+      # @param [ Document, Object ] other The other object to compare with.
+      #
+      # @return [ true, false ] True if the classes are equal, false if not.
+      def ===(other)
+        if Mongoid.legacy_triple_equals
+          other.is_a?(self)
+        else
+          other.class == Class ? self <= other : other.is_a?(self)
+        end
+      end
+    end
   end
 end

spec/mongoid/equality_spec.rb

@@ -85,151 +85,123 @@
 
   describe ".===" do
 
-    context "when comparable is an instance of this document" do
+    context "when legacy_triple_equals is set" do
+      config_override :legacy_triple_equals, true
+
+      context "when comparable is an instance of this document" do
 
-      with_config_values :legacy_triple_equals, false, true do
         it "returns true" do
           expect(klass === person).to be true
         end
       end
-    end
 
-    context "when comparable is a relation of this document" do
+      context "when comparable is a relation of this document" do
 
-      let(:relation) do
-        Post.new(person: person).person
-      end
+        let(:relation) do
+          Post.new(person: person).person
+        end
 
-      with_config_values :legacy_triple_equals, false, true do
         it "returns true" do
           expect(klass === relation).to be true
         end
       end
-    end
 
-    context "when comparable is the same class" do
-
-      context "when legacy_triple_equals is not set" do
-        config_override :legacy_triple_equals, false
+      context "when comparable is the same class" do
 
         it "returns false" do
           expect(klass === Person).to be false
         end
       end
 
-      context "when legacy_triple_equals is set" do
-        config_override :legacy_triple_equals, true
-
-        it "returns true" do
-          expect(klass === Person).to be true
-        end
-      end
-    end
-
-    context "when the comparable is a subclass" do
+      context "when the comparable is a subclass" do
 
-      with_config_values :legacy_triple_equals, false, true do
         it "returns false" do
           expect(Person === Doctor).to be false
         end
       end
-    end
 
-    context "when the comparable is an instance of a subclass" do
+      context "when the comparable is an instance of a subclass" do
 
-      with_config_values :legacy_triple_equals, false, true do
         it "returns true" do
           expect(Person === Doctor.new).to be true
         end
       end
     end
 
-    context "when comparing to a class" do
-
-      context "when legacy_triple_equals is not set" do
-        config_override :legacy_triple_equals, false
+    context "when legacy_triple_equals is not set" do
+      config_override :legacy_triple_equals, false
 
-        context "when the class is the same" do
+      context "when comparable is an instance of this document" do
 
-          it "returns false" do
-            expect(Person === Person).to be false
-          end
+        it "returns true" do
+          expect(klass === person).to be true
         end
+      end
 
-        context "when the class is a subclass" do
+      context "when comparable is a relation of this document" do
 
-          it "returns false" do
-            expect(Person === Doctor).to be false
-          end
+        let(:relation) do
+          Post.new(person: person).person
         end
 
-        context "when the class is a superclass" do
-
-          it "returns false" do
-            expect(Doctor === Person).to be false
-          end
+        it "returns true" do
+          expect(klass === relation).to be true
         end
       end
 
-      context "when legacy_triple_equals is set" do
-        config_override :legacy_triple_equals, true
+      context "when comparable is the same class" do
 
-        context "when the class is the same" do
-
-          it "returns true" do
-            expect(Person === Person).to be true
-          end
+        it "returns true" do
+          expect(klass === Person).to be true
         end
+      end
 
-        context "when the class is a subclass" do
+      context "when the comparable is a subclass" do
 
-          it "returns false" do
-            expect(Person === Doctor).to be false
-          end
+        it "returns false" do
+          expect(Person === Doctor).to be false
         end
+      end
 
-        context "when the class is a superclass" do
+      context "when the comparable is an instance of a subclass" do
 
-          it "returns true" do
-            expect(Doctor === Person).to be true
-          end
+        it "returns true" do
+          expect(Person === Doctor.new).to be true
         end
       end
     end
   end
 
   describe "#===" do
 
-    context "when comparable is the same type" do
+    context "when legacy_triple_equals is set" do
+      config_override :legacy_triple_equals, true
 
-      context "when the instance is different" do
+      context "when comparable is the same type" do
 
-        it "returns false" do
-          expect(person === Person.new).to be false
+        context "when the instance is different" do
+
+          it "returns false" do
+            expect(person === Person.new).to be false
+          end
         end
-      end
 
-      context "when the instance is the same" do
+        context "when the instance is the same" do
 
-        it "returns true" do
-          expect(person === person).to be true
+          it "returns true" do
+            expect(person === person).to be true
+          end
         end
       end
-    end
 
-    context "when the comparable is a subclass" do
+      context "when the comparable is a subclass" do
 
-      with_config_values :legacy_triple_equals, false, true do
         it "returns false" do
           expect(person === Doctor.new).to be false
         end
       end
-    end
-
-    context "when comparing to a class" do
 
-      context "when legacy_triple_equals is not set" do
-        config_override :legacy_triple_equals, false
+      context "when comparing to a class" do
 
         context "when the class is the same" do
 
@@ -252,10 +224,36 @@
           end
         end
       end
+    end
+
+    context "when legacy_triple_equals is not set" do
+      config_override :legacy_triple_equals, false
+
+      context "when comparable is the same type" do
+
+        context "when the instance is different" do
+
+          it "returns false" do
+            expect(person === Person.new).to be false
+          end
+        end
 
-      context "when legacy_triple_equals is set" do
-        config_override :legacy_triple_equals, true
+        context "when the instance is the same" do
+
+          it "returns true" do
+            expect(person === person).to be true
+          end
+        end
+      end
+
+      context "when the comparable is a subclass" do
+
+        it "returns false" do
+          expect(person === Doctor.new).to be false
+        end
+      end
 
+      context "when comparing to a class" do
         context "when the class is the same" do
 
           it "returns true" do