From 6bf051bdb8aa3c873e0def927ecd724dcac06895 Mon Sep 17 00:00:00 2001
From: Brian Shand <Brian.Shand@nhs.net>
Date: Mon, 13 Oct 2025 10:03:02 +0100
Subject: [PATCH] Add fix for capybara/chromedriver issue

Our feature tests using Capybara and Chromedriver are intermittently
failing with the following error:

unknown error: unhandled inspector error: {"code":-32000,"message":"Node with given id does not
belong to the document"}

This can usually be fixed by rerunning the tests.

In our CI environments and end-to-end tests we pin chrome to 128 where
the issue doesn't occur.

It's harder to pin chrome in local development environments.

This commit takes a different approach found in a comment on the
capabara issue: It adds a monkey patch to the Selenium driver to
intercept the initialization of `UnknownError` and raise a
`StaleElementReferenceError` instead.

This makes the test retry.

This commit can be reverted once the issue is resolved.

teamcapybara/capybara#2800
---
 test/selenium_error_patch.rb | 37 ++++++++++++++++++++++++++++++++++++
 test/test_helper.rb          |  1 +
 2 files changed, 38 insertions(+)
 create mode 100644 test/selenium_error_patch.rb

diff --git a/test/selenium_error_patch.rb b/test/selenium_error_patch.rb
new file mode 100644
index 00000000..ad06f2c0
--- /dev/null
+++ b/test/selenium_error_patch.rb
@@ -0,0 +1,37 @@
+# Taken from https://github.com/alphagov/forms-admin/commit/5ea98767d765a396ed06cf2cba8f9afb1b10fc0e#diff-c36c07a0c7f499b1b95634f9dce1a10ebf4d10a9dee872f39f746a9efa555ddbR1-R34
+# Monkey patch for a specific intermittent Selenium error.
+#
+# Intermittently, Selenium/Chromedriver raises `Selenium::WebDriver::Error::UnknownError`
+# with the message "Node with given id does not belong to the document".
+
+# Capybara's automatic waiting/retrying mechanism doesn't catch it,
+# leading to failure.
+#
+# We intercept the initialization of `UnknownError`. If the message matches this specific
+# case, we raise a `StaleElementReferenceError` instead. This uses Capybara's
+# retry logic which makes doesn't fail the test
+#
+# This can be removed once the following issue is resolved:
+# https://github.com/teamcapybara/capybara/issues/2800
+#
+# taken from the following issue:
+# https://github.com/teamcapybara/capybara/issues/2800#issuecomment-3049956982
+
+# rubocop:disable Style/Alias, Style/IfUnlessModifier, Style/StringLiterals
+module Selenium
+  module WebDriver
+    module Error
+      class UnknownError
+        alias_method :old_initialize, :initialize
+        def initialize(msg = nil)
+          if msg&.include?("Node with given id does not belong to the document")
+            raise StaleElementReferenceError, msg
+          end
+
+          old_initialize(msg)
+        end
+      end
+    end
+  end
+end
+# rubocop:enable Style/Alias, Style/IfUnlessModifier, Style/StringLiterals
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 6cdb35bf..47caa019 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -19,6 +19,7 @@
 require 'pry'
 require 'capybara/email'
 require 'create_records_helper'
+require 'selenium_error_patch'
 
 require_relative 'download_helpers'