RUBY-2158 Return UTC times when parsing extended json (#192)

Co-authored-by: Oleg Pudeyev <[email protected]>

Author: p-mongo

lib/bson/ext_json.rb

@@ -251,13 +251,13 @@ module ExtJSON
         when '$date'
           case value
           when String
-            ::Time.parse(value)
+            ::Time.parse(value).utc
           when Hash
             unless value.keys.sort == %w($numberLong)
               raise Error::ExtJSONParseError, "Invalid value for $date: #{value}"
             end
             sec, msec = value.values.first.to_i.divmod(1000)
-            ::Time.at(sec, msec*1000)
+            ::Time.at(sec, msec*1000).utc
           else
             raise Error::ExtJSONParseError, "Invalid value for $date: #{value}"
           end

spec/bson/ext_json_parse_spec.rb

@@ -50,14 +50,46 @@
     end
   end
 
-  context 'when input is a timestamp' do
+  context 'when input is a BSON timestamp' do
     let(:input) { {'$timestamp' => {'t' => 12345, 'i' => 42}} }
 
-    it 'returns a timestamp object' do
+    it 'returns a BSON::Timestamp instance' do
       parsed.should == BSON::Timestamp.new(12345, 42)
     end
   end
 
+  context 'when input is an ISO time' do
+    let(:input) { {'$date' => '1970-01-01T00:00:04Z'} }
+
+    it 'returns a Time instance ' do
+      parsed.should be_a(Time)
+    end
+
+    it 'returns a Time instance with correct value' do
+      parsed.should == Time.at(4)
+    end
+
+    it 'returns a Time instance in UTC' do
+      parsed.zone.should == 'UTC'
+    end
+  end
+
+  context 'when input is a Unix timestamp' do
+    let(:input) { {'$date' => {'$numberLong' => '4000'}} }
+
+    it 'returns a Time instance ' do
+      parsed.should be_a(Time)
+    end
+
+    it 'returns a Time instance with correct value' do
+      parsed.should == Time.at(4)
+    end
+
+    it 'returns a Time instance in UTC' do
+      parsed.zone.should == 'UTC'
+    end
+  end
+
   context 'when input is an int32' do
     let(:input) do
       {'$numberInt' => '42'}