Rework Node#obscured? frame support in JavaScript

Teaches `isObscured` how to traverse nested frames.

Author: myabc

lib/capybara/cuprite/browser.rb

@@ -211,14 +211,11 @@ def path(node)
       end
 
       def obscured?(node, x = nil, y = nil)
-        value = if x && y
-                  evaluate_on(node: node, expression: "_cuprite.isObscured(this, #{x}, #{y})")
-                else
-                  evaluate_on(node: node, expression: "_cuprite.isObscured(this)")
-                end
-        return true if value == true
-
-        frame_obscured_at?(*value.values_at("x", "y"))
+        if x && y
+          evaluate_on(node: node, expression: "_cuprite.isObscured(this, #{x}, #{y})")
+        else
+          evaluate_on(node: node, expression: "_cuprite.isObscured(this)")
+        end
       end
 
       def all_text(node)
@@ -268,21 +265,6 @@ def attach_page(target_id = nil)
         target.page = Page.new(target.client, context_id: target.context_id, target_id: target.id)
         target.page
       end
-
-      def frame_obscured_at?(x, y)
-        frame = page.active_frame
-        return false if frame.main?
-
-        frame_node = frame.evaluate("window.frameElement")
-        return false unless frame_node
-
-        switch_to_frame(:parent)
-        begin
-          obscured?(frame_node, x, y)
-        ensure
-          switch_to_frame(frame)
-        end
-      end
     end
   end
 end

lib/capybara/cuprite/javascripts/index.js

@@ -115,16 +115,38 @@ class Cuprite {
     return `//${selectors.join("/")}`;
   }
 
+  /**
+   * Returns true if the node is obscured in the viewport.
+   *
+   * @param {Element} node
+   * @param {number} [x] the center position
+   * @param {number} [y] the center position
+   * @return {boolean} true if the node is obscured, false otherwise
+   */
   isObscured(node, x, y) {
+    let win = window;
     let rect = node.getBoundingClientRect();
-    if (x == null) x = rect.width/2;
-    if (y == null) y = rect.height/2;
+    x = x ?? rect.width / 2;
+    y = y ?? rect.height / 2;
 
     let px = rect.left + x;
     let py = rect.top + y;
-    let e = document.elementFromPoint(px, py);
 
-    return !node.contains(e) || { x: px, y: py };
+    while (win) {
+      let topNode = win.document.elementFromPoint(px, py);
+
+      if (node !== topNode && !node.contains(topNode)) return true;
+
+      node = win.frameElement;
+      if (!node) return false;
+
+      rect = node.getBoundingClientRect();
+      px = rect.left + px;
+      py = rect.top + py;
+      win = win.parent;
+    }
+
+    return false;
   }
 
   set(node, value) {