MONGOID-5410 change Hash#mongoize to always return BSON::Documents (#5420)

* MONGOID-5410 change Hash#mongoize to always return BSON::Documents

* MONGOID-5410 fix tests

Author: neilshweky

lib/mongoid/extensions/hash.rb

@@ -220,11 +220,11 @@ module ClassMethods
         # @return [ Hash | nil ] The object mongoized or nil.
         def mongoize(object)
           return if object.nil?
-          if object.is_a?(Hash)
-            # Need to use transform_values! which maintains the BSON::Document
-            # instead of transform_values which always returns a hash. To do this,
-            # we first need to dup the hash.
+          case object
+          when BSON::Document
             object.dup.transform_values!(&:mongoize)
+          when Hash
+            BSON::Document.new(object.transform_values(&:mongoize))
           end
         end
 

spec/mongoid/attributes_spec.rb

@@ -1593,8 +1593,8 @@
         expect(person.map).to be_nil
       end
 
-      it "can set a Hash value" do
-        expect(person.map).to eq( { somekey: "somevalue" } )
+      it "can set a Hash value with stringified keys" do
+        expect(person.map).to eq( { "somekey" => "somevalue" } )
       end
     end
 

spec/mongoid/changeable_spec.rb

@@ -207,13 +207,13 @@
 
         it "returns an array of the original value and new value" do
           expect(person.send(:attribute_change, "map")).to eq(
-            [{ location: "Home" }, { location: "Work" }]
+            [{ "location" => "Home" }, { "location" => "Work" }]
           )
         end
 
         it "allows access via (attribute)_change" do
           expect(person.map_change).to eq(
-            [{ location: "Home" }, { location: "Work" }]
+            [{ "location" => "Home" }, { "location" => "Work" }]
           )
         end
 
@@ -225,7 +225,7 @@
 
           it "returns an array of the original value and new value" do
             expect(person.send(:attribute_change, "map")).to eq(
-              [{ location: "Home" }, { location: "Work", lat: 20.0 }]
+              [{ "location" => "Home" }, { "location" => "Work", "lat" => 20.0 }]
             )
           end
         end

spec/mongoid/extensions/hash_spec.rb

@@ -335,6 +335,10 @@
       it "converts the elements properly" do
         expect(mongoized[:date]).to eq(Time.utc(2012, 1, 1, 0, 0, 0))
       end
+
+      it "mongoizes to a BSON::Document" do
+        expect(mongoized).to be_a(BSON::Document)
+      end
     end
 
     context "when object is nil" do
@@ -356,6 +360,20 @@
         expect(mongoized).to be_nil
       end
     end
+
+    describe "when mongoizing a BSON::Document" do
+      let(:mongoized) do
+        Hash.mongoize(BSON::Document.new({ x: 1, y: 2 }))
+      end
+
+      it "returns the same hash" do
+        expect(mongoized).to eq({ "x" => 1, "y" => 2 })
+      end
+
+      it "returns a BSON::Document" do
+        expect(mongoized).to be_a(BSON::Document)
+      end
+    end
   end
 
   describe "#mongoize" do

spec/mongoid/fields_spec.rb

@@ -893,6 +893,34 @@
         expect(product.attributes_before_type_cast["price"]).to eq(1)
       end
     end
+
+    context "when assigning a hash" do
+      let(:person) { Person.create!(map: { x: 1 }) }
+
+      it "is a BSON::Document" do
+        expect(person.map).to be_a(BSON::Document)
+      end
+
+      it "has the correct contents" do
+        expect(person.map).to eq({ "x" => 1 })
+      end
+    end
+
+    context "when loading a hash from the db" do
+      before do
+        Person.create!(map: { x: 1 })
+      end
+
+      let(:person) { Person.first }
+
+      it "is a BSON::Document" do
+        expect(person.map).to be_a(BSON::Document)
+      end
+
+      it "has the correct contents" do
+        expect(person.map).to eq({ "x" => 1 })
+      end
+    end
   end
 
   describe "#defaults" do