Raise ObsoleteNode when a node is detached before the click hit test

CHANGELOG.md

@@ -12,6 +12,8 @@
   [rubycdp/ferrum#689]
 
 ### Fixed
+- A click on a node the page removes before the hit test raises `ObsoleteNode`, which Capybara retries, instead of
+  `Ferrum::JavaScriptError: node.getRootNode(...).elementFromPoint is not a function` [#359]
 
 ### Removed
 - Methods deprecated in 0.20, see its Deprecated section for replacements

lib/capybara/cuprite/javascripts/index.js

@@ -4,6 +4,7 @@
   class InvalidSelector extends Error {}
   class TimedOutPromise extends Error {}
   class MouseEventFailed extends Error {}
+  class ObsoleteNode extends Error {}
 
   const EVENTS = {
     FOCUS: ["blur", "focus", "focusin", "focusout"],
@@ -329,6 +330,10 @@
     }
 
     mouseEventTest(node, name, x, y) {
+      // The page can remove the node after Ruby checked it; getRootNode() would
+      // then return the detached subtree, which has no elementFromPoint.
+      if (!node.isConnected) throw new ObsoleteNode();
+
       let frameOffset = this._frameOffset();
       x -= frameOffset.left;
       y -= frameOffset.top;

lib/capybara/cuprite/node.rb

@@ -274,6 +274,7 @@ def before_click(name, offset = {})
         js(:mouseEventTest, name.to_s, x, y)
       rescue Ferrum::JavaScriptError => e
         raise MouseEventFailed, e.message if e.class_name == "MouseEventFailed"
+        raise ObsoleteNode.new(self, e.response) if e.class_name == "ObsoleteNode"
 
         raise
       end

spec/node_spec.rb

@@ -95,6 +95,19 @@
         .to raise_error(Capybara::Cuprite::MouseEventFailed)
     end
 
+    it "raises ObsoleteNode for an element removed before the hit test" do
+      @session.visit("/cuprite/with_js")
+      node = @session.find(:css, "#remove_me")
+      # The page removes the node after Ruby checked it and before the hit test runs.
+      @session.execute_script(<<~JS)
+        const test = _cuprite.mouseEventTest;
+        _cuprite.mouseEventTest = function(node, ...args) { node.remove(); return test.call(this, node, ...args); };
+      JS
+
+      # native.click bypasses Capybara::Node::Element#reload, which would re-find and retry.
+      expect { node.native.click }.to raise_error(Capybara::Cuprite::ObsoleteNode)
+    end
+
     it "clicks an element brought into the viewport" do
       @session.visit("/cuprite/with_js")
       @session.execute_script %($("#off-the-left").animate({left: "10"});)