Allow to listen for JavaScript exceptions

common/src/web/javascriptPage.html

@@ -86,7 +86,7 @@ <h1>Type Stuff</h1>
   </div>
 
 </div>
-                                                                                         
+
 <div id="formageddon">
     <form action="#">
         Key Up: <input type="text" id="keyUp" onkeyup="javascript:updateContent(this)"/><br/>
@@ -151,15 +151,15 @@ <h1>Type Stuff</h1>
            />
 
     <input id="changeable" name="changeable" onfocus="appendMessage('focus')" onchange="appendMessage('change')" onblur="appendMessage('blur')"/>
-           
-    <button type="button" id="plainButton" 
+
+    <button type="button" id="plainButton"
     		onfocus="appendMessage('focus')"
            	onkeydown="appendMessage('keydown')"
            	onkeypress="appendMessage('keypress')"
            	onkeyup="appendMessage('keyup')"
            	onblur="appendMessage('blur')"
            	onclick="appendMessage('click')"
-           	onmousedown="appendMessage('mousedown ')" 
+           	onmousedown="appendMessage('mousedown ')"
            	onmouseup="appendMessage('mouseup ')"
             onmouseover="register('mouseover ')"
             onmousemove="register('mousemove ')"
@@ -173,7 +173,7 @@ <h1>Type Stuff</h1>
     <button type="button" onclick="var element = document.getElementById('switchFocus'); var clickEvent = document.createEvent('MouseEvents'); clickEvent.initMouseEvent('click', true, true, null, 0, 0, 0, 0, 0,false, false, false, false, 0, element);element.dispatchEvent(clickEvent);">Do magic</button><br/>
     <label id="labelForCheckbox" for="labeledCheckbox" onclick="appendMessage('labelclick')">Toggle checkbox</label><input type="checkbox" id="labeledCheckbox" onclick="appendMessage('chboxclick')"/>
   </form>
-  
+
   <form action="javascriptPage.html" id="submitListeningForm" onsubmit="appendMessage('form-onsubmit '); return false;">
     <p>
       <input id="submitListeningForm-text" type="text" onsubmit="appendMessage('text-onsubmit ')" onclick="appendMessage('text-onclick ');" />
@@ -198,7 +198,7 @@ <h1>Type Stuff</h1>
         <a href="#" id="hiddenlink">ok</a>
       </div>
     </div>
-    
+
     <div style="visibility: hidden;">
       <span>
         <input id="unclickable" />
@@ -265,7 +265,7 @@ <h1>Type Stuff</h1>
 
 <a id="new_window" onmouseup="window.open('closeable_window.html', 'close_me')" href="#">Click me to open a new window</a>
 
-<a id="throwing-mouseover" onmouseover="throw new Error()" href="#throwing-mouseover">Mouse over me will throw a JS error</a>
+<a id="throwing-mouseover" onmouseover="throw new Error('I like cheese')" href="#throwing-mouseover">Mouse over me will throw a JS error</a>
 
 <div id="parent">
     <span id="movable" onmouseover="var p = document.getElementById('movable'); displayMessage('parent matches? ' + (p != event.relatedTarget));">

rb/lib/selenium/webdriver/common/driver_extensions/has_log_events.rb

@@ -21,46 +21,76 @@ module Selenium
   module WebDriver
     module DriverExtensions
       module HasLogEvents
+        KINDS = %i[console exception].freeze
 
-        #
         #
         # Registers listener to be called whenever browser receives
-        # a new Console API message such as console.log().
+        # a new Console API message such as console.log() or an unhandled
+        # exception.
+        #
         # This currently relies on DevTools so is only supported in
         # Chromium browsers.
         #
-        # @example
+        # @example Collect console messages
         #   logs = []
-        #   driver.on_log_event do |event|
+        #   driver.on_log_event(:console) do |event|
         #     logs.push(event)
         #   end
         #
-        # @param [#call] block which yields DevTools::ConsoleEvent
+        # @example Collect JavaScript exceptions
+        #   exceptions = []
+        #   driver.on_log_event(:exception) do |event|
+        #     exceptions.push(event)
+        #   end
         #
+        # @param [Symbol] kind :console or :exception
+        # @param [#call] block which is called when event happens
+        # @yieldparam [DevTools::ConsoleEvent, DevTools::ExceptionEvent]
+        #
+
+        def on_log_event(kind, &block)
+          raise WebDriverError, "Don't know how to handle #{kind} events" unless KINDS.include?(kind)
 
-        def on_log_event(&block)
-          console_listeners_enabled = console_listeners.any?
-          console_listeners << block
-          return if console_listeners_enabled
+          enabled = log_listeners[kind].any?
+          log_listeners[kind] << block
+          return if enabled
 
           devtools.runtime.enable
+          __send__("log_#{kind}_events")
+        end
+
+        private
+
+        def log_listeners
+          @log_listeners ||= Hash.new { |listeners, kind| listeners[kind] = [] }
+        end
+
+        def log_console_events
           devtools.runtime.on(:console_api_called) do |params|
             event = DevTools::ConsoleEvent.new(
               type: params['type'],
               timestamp: params['timestamp'],
               args: params['args']
             )
 
-            console_listeners.each do |listener|
+            log_listeners[:console].each do |listener|
               listener.call(event)
             end
           end
         end
 
-        private
+        def log_exception_events
+          devtools.runtime.on(:exception_thrown) do |params|
+            event = DevTools::ExceptionEvent.new(
+              description: params.dig('exceptionDetails', 'exception', 'description'),
+              timestamp: params['timestamp'],
+              stacktrace: params.dig('exceptionDetails', 'stackTrace', 'callFrames')
+            )
 
-        def console_listeners
-          @console_listeners ||= []
+            log_listeners[:exception].each do |listener|
+              listener.call(event)
+            end
+          end
         end
 
       end # HasLogEvents

rb/lib/selenium/webdriver/devtools.rb

@@ -21,6 +21,7 @@ module Selenium
   module WebDriver
     class DevTools
       autoload :ConsoleEvent, 'selenium/webdriver/devtools/console_event'
+      autoload :ExceptionEvent, 'selenium/webdriver/devtools/exception_event'
 
       SUPPORTED_VERSIONS = [84, 85, 86].freeze
 

rb/lib/selenium/webdriver/devtools/exception_event.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+module Selenium
+  module WebDriver
+    class DevTools
+      class ExceptionEvent
+
+        attr_accessor :description, :timestamp, :stacktrace
+
+        def initialize(description:, timestamp:, stacktrace:)
+          @description = description
+          @timestamp = Time.at(timestamp / 1000)
+          @stacktrace = stacktrace
+        end
+
+      end # ExceptionEvent
+    end # DevTools
+  end # WebDriver
+end # Selenium

rb/spec/integration/selenium/webdriver/devtools_spec.rb

@@ -64,7 +64,7 @@ module WebDriver
 
       it 'notifies about log messages' do
         logs = []
-        driver.on_log_event { |log| logs.push(log) }
+        driver.on_log_event(:console) { |log| logs.push(log) }
         driver.navigate.to url_for('javascriptPage.html')
 
         driver.execute_script("console.log('I like cheese');")
@@ -82,6 +82,19 @@ module WebDriver
           an_object_having_attributes(type: :log, args: [hash_including('type' => 'object')])
         )
       end
+
+      it 'notifies about exceptions' do
+        exceptions = []
+        driver.on_log_event(:exception) { |exception| exceptions.push(exception) }
+        driver.navigate.to url_for('javascriptPage.html')
+
+        driver.find_element(id: 'throwing-mouseover').click
+        wait.until { exceptions.any? }
+
+        exception = exceptions.first
+        expect(exception.description).to include('Error: I like cheese')
+        expect(exception.stacktrace).not_to be_empty
+      end
     end
   end
 end