Add Message#reply_privately.

lib/lita/message.rb

@@ -68,5 +68,13 @@ def match(pattern)
     def reply(*strings)
       @robot.send_messages(source, *strings)
     end
+
+    # Replies by sending the given strings back to the user who sent the
+    # message directly, even if the message was sent in a room.
+    # @param strings [String, Array<String>] The strings to send back.
+    # @return [void]
+    def reply_privately(*strings)
+      @robot.send_messages(Source.new(source.user), *strings)
+    end
   end
 end

spec/lita/message_spec.rb

@@ -71,4 +71,19 @@
       subject.reply("foo", "bar")
     end
   end
+
+  describe "#reply_privately" do
+    it "sends strings directly to the source user" do
+      subject = described_class.new(
+        robot,
+        "Hello",
+        Lita::Source.new("Carl", "#room")
+      )
+      expect(robot).to receive(:send_messages) do |source, *strings|
+        expect(source.room).to be_nil
+        expect(strings).to eq(["foo", "bar"])
+      end
+      subject.reply_privately("foo", "bar")
+    end
+  end
 end