implement Browser#drag and #drag_by.

Author: botandrose-machine

lib/capybara/cuprite/browser.rb

@@ -113,11 +113,23 @@ def source
       end
 
       def drag(node, other)
-        raise NotImplementedError
+        x1, y1 = node.find_position
+        x2, y2 = other.find_position
+
+        mouse.move(x: x1, y: y1)
+        mouse.down
+        mouse.move(x: x2, y: y2)
+        mouse.up
       end
 
       def drag_by(node, x, y)
-        raise NotImplementedError
+        x1, y1 = node.find_position
+        x2, y2 = x1 + x, y1 + y
+
+        mouse.move(x: x1, y: y1)
+        mouse.down
+        mouse.move(x: x2, y: y2)
+        mouse.up
       end
 
       def select_file(node, value)

lib/capybara/cuprite/node.rb

@@ -160,7 +160,7 @@ def hover
       end
 
       def drag_to(other)
-        command(:drag, other)
+        command(:drag, other.node)
       end
 
       def drag_by(x, y)

spec/features/session_spec.rb

@@ -575,7 +575,7 @@
       end
     end
 
-    context "dragging support", skip: true do
+    context "dragging support" do
       before do
         @session.visit "/cuprite/drag"
       end