Split into a few methods

lib/ferrum.rb

@@ -8,7 +8,6 @@ class Error               < StandardError; end
   class NoSuchPageError     < Error; end
   class NoSuchTargetError   < Error; end
   class NotImplementedError < Error; end
-  class NodeIsMovingError   < Error; end
 
   class StatusError < Error
     def initialize(url, pendings = [])
@@ -49,6 +48,12 @@ def initialize(message = "Browser is dead or given window is closed")
     end
   end
 
+  class NodeIsMovingError < Error
+    def initialize(node)
+      super("Node `#{node.inspect}` that you're trying to click is moving, hence we cannot")
+    end
+  end
+
   class BrowserError < Error
     attr_reader :response
 

lib/ferrum/node.rb

@@ -124,44 +124,31 @@ def inspect
     end
 
     def find_position(x: nil, y: nil, position: :top)
-      offset_x, offset_y = x, y
-      quads = get_node_quads
-      x = y = nil
-
-      if offset_x && offset_y && position == :top
-        point = quads.first
-        x = point[:x] + offset_x.to_i
-        y = point[:y] + offset_y.to_i
-      else
-        x, y = quads.inject([0, 0]) do |memo, point|
-          [memo[0] + point[:x],
-           memo[1] + point[:y]]
-        end
-
-        x = x / 4
-        y = y / 4
-      end
-
-      if offset_x && offset_y && position == :center
-        x = x + offset_x.to_i
-        y = y + offset_y.to_i
-      end
-
-      [x, y]
+      quads = node_quads(x, y)
+      get_position(quads, x, y)
     end
 
     private
 
-    def get_node_quads
+    def get_content_quads
+      result = page.command("DOM.getContentQuads", nodeId: node_id)
+      raise "Node is either not visible or not an HTMLElement" if result["quads"].size == 0
+      result
+    end
+
+    def node_quads(x, y)
       prev_result = get_content_quads
 
       result = Ferrum.with_attempts(errors: NodeIsMovingError, max: MOVING_ATTEMPTS, wait: 0) do
         sleep(MOVING_WAIT)
         current_result = get_content_quads
 
         if current_result["quads"] != prev_result["quads"]
+          prev_pos = get_position(prev_result, x, y)
+          current_pos = get_position(current_result, x, y)
+
           prev_result = current_result
-          raise NodeIsMovingError
+          raise NodeIsMovingError.new(self, prev_pos, current_pos)
         end
 
         current_result
@@ -176,10 +163,29 @@ def get_node_quads
       end.first
     end
 
-    def get_content_quads
-      result = page.command("DOM.getContentQuads", nodeId: node_id)
-      raise "Node is either not visible or not an HTMLElement" if result["quads"].size == 0
-      result
+    def get_position(quads, offset_x, offset_y)
+      x = y = nil
+
+      if offset_x && offset_y && position == :top
+        point = quads.first
+        x = point[:x] + offset_x.to_i
+        y = point[:y] + offset_y.to_i
+      else
+        x, y = quads.inject([0, 0]) do |memo, point|
+          [memo[0] + point[:x],
+           memo[1] + point[:y]]
+        end
+
+        x = x / 4
+        y = y / 4
+      end
+
+      if offset_x && offset_y && position == :center
+        x = x + offset_x.to_i
+        y = y + offset_y.to_i
+      end
+
+      [x, y]
     end
   end
 end