[dotnet] Add ability to monitor DOM mutations

dotnet/src/webdriver/BUILD.bazel

@@ -56,6 +56,7 @@ generated_assembly_info(
         "//javascript/atoms/fragments:find-elements.js",
         "//javascript/atoms/fragments:is-displayed.js",
         "//javascript/webdriver/atoms:get-attribute.js",
+        "//javascript/cdp-support:mutation-listener.js",
         "//third_party/js/selenium:webdriver_json",
     ],
     target_frameworks = [
@@ -101,6 +102,7 @@ generated_assembly_info(
         "//javascript/atoms/fragments:find-elements.js",
         "//javascript/atoms/fragments:is-displayed.js",
         "//javascript/webdriver/atoms:get-attribute.js",
+        "//javascript/cdp-support:mutation-listener.js",
         "//third_party/js/selenium:webdriver_json",
     ],
     target_frameworks = [
@@ -138,6 +140,7 @@ generated_assembly_info(
         "//javascript/atoms/fragments:find-elements.js",
         "//javascript/atoms/fragments:is-displayed.js",
         "//javascript/webdriver/atoms:get-attribute.js",
+        "//javascript/cdp-support:mutation-listener.js",
         "//third_party/js/selenium:webdriver_json",
     ],
     target_frameworks = [
@@ -184,6 +187,7 @@ generated_assembly_info(
         "//javascript/atoms/fragments:find-elements.js",
         "//javascript/atoms/fragments:is-displayed.js",
         "//javascript/webdriver/atoms:get-attribute.js",
+        "//javascript/cdp-support:mutation-listener.js",
         "//third_party/js/selenium:webdriver_json",
     ],
     target_frameworks = [

dotnet/src/webdriver/DomMutatedEventArgs.cs

@@ -0,0 +1,39 @@
+// <copyright file="DomMutatedEventArgs.cs" company="WebDriver Committers">
+// 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.
+// </copyright>
+
+using System;
+
+namespace OpenQA.Selenium
+{
+    /// <summary>
+    /// Provides data for the AttributeValueChanged event
+    /// </summary>
+    public class DomMutatedEventArgs : EventArgs
+    {
+        private DomMutationData attributeData;
+
+        /// <summary>
+        /// Gets the data about the attribute being changed.
+        /// </summary>
+        public DomMutationData AttributeData
+        {
+            get { return this.attributeData; }
+            internal set { this.attributeData = value; }
+        }
+    }
+}

dotnet/src/webdriver/DomMutationData.cs

@@ -0,0 +1,82 @@
+// <copyright file="DomMutationData.cs" company="WebDriver Committers">
+// 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.
+// </copyright>
+
+using Newtonsoft.Json;
+
+namespace OpenQA.Selenium
+{
+    /// <summary>
+    /// Provides data about the changes in the value of an attribute on an element.
+    /// </summary>
+    public class DomMutationData
+    {
+        private string targetId;
+        private string attributeName;
+        private string attributeValue;
+        private string attributeOriginalValue;
+
+        /// <summary>
+        /// Gets the ID of the element whose value is changing.
+        /// </summary>
+        [JsonProperty(PropertyName = "target")]
+        public string TargetId
+        {
+            get { return this.targetId; }
+            internal set { this.targetId = value; }
+        }
+
+        /// <summary>
+        /// Gets the name of the attribute that is changing.
+        /// </summary>
+        [JsonProperty(PropertyName = "name")]
+        public string AttributeName
+        {
+            get { return this.attributeName; }
+            internal set { this.attributeName = value; }
+        }
+
+        /// <summary>
+        /// Gets the value to which the attribute is being changed.
+        /// </summary>
+        [JsonProperty(PropertyName = "value")]
+        public string AttributeValue
+        {
+            get { return this.attributeValue; }
+            internal set { this.attributeValue = value; }
+        }
+
+        /// <summary>
+        /// Gets the value from which the attribute has been changed.
+        /// </summary>
+        [JsonProperty(PropertyName = "oldValue")]
+        public string AttributeOriginalValue
+        {
+            get { return this.attributeOriginalValue; }
+            internal set { this.attributeOriginalValue = value; }
+        }
+
+        /// <summary>
+        /// Returns a string that represents the current object.
+        /// </summary>
+        /// <returns>A string that represents the current object.</returns>
+        public override string ToString()
+        {
+            return string.Format("target: {0}, name: {1}, value: {2}, originalValue: {3}", this.targetId, this.attributeName, this.attributeValue, this.attributeOriginalValue);
+        }
+    }
+}

dotnet/src/webdriver/IJavaScriptEngine.cs

@@ -42,6 +42,11 @@ public interface IJavaScriptEngine
         /// </summary>
         event EventHandler<JavaScriptConsoleApiCalledEventArgs> JavaScriptConsoleApiCalled;
 
+        /// <summary>
+        /// Occurs when a value of an attribute in an element is being changed.
+        /// </summary>
+        event EventHandler<DomMutatedEventArgs> DomMutated;
+
         /// <summary>
         /// Gets the read-only list of initialization scripts added for this JavaScript engine.
         /// </summary>
@@ -63,6 +68,18 @@ public interface IJavaScriptEngine
         /// </summary>
         void StopEventMonitoring();
 
+        /// <summary>
+        /// Enables monitoring for DOM changes.
+        /// </summary>
+        /// <returns>A task that represents the asynchronous operation.</returns>
+        Task EnableDomMutationMonitoring();
+
+        /// <summary>
+        /// Disables monitoring for DOM changes.
+        /// </summary>
+        /// <returns>A task that represents the asynchronous operation.</returns>
+        Task DisableDomMutationMonitoring();
+
         /// <summary>
         /// Asynchronously adds JavaScript to be loaded on every document load.
         /// </summary>

dotnet/src/webdriver/JavaScriptEngine.cs

@@ -19,8 +19,11 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.IO;
 using System.Threading.Tasks;
+using Newtonsoft.Json;
 using OpenQA.Selenium.DevTools;
+using OpenQA.Selenium.Internal;
 
 namespace OpenQA.Selenium
 {
@@ -29,6 +32,8 @@ namespace OpenQA.Selenium
     /// </summary>
     public class JavaScriptEngine : IJavaScriptEngine
     {
+        private readonly string MonitorBindingName = "__webdriver_attribute";
+
         private IWebDriver driver;
         private Lazy<DevToolsSession> session;
         private Dictionary<string, InitializationScript> initializationScripts = new Dictionary<string, InitializationScript>();
@@ -73,6 +78,11 @@ public JavaScriptEngine(IWebDriver driver)
         /// </summary>
         public event EventHandler<JavaScriptConsoleApiCalledEventArgs> JavaScriptConsoleApiCalled;
 
+        /// <summary>
+        /// Occurs when a value of an attribute in an element is being changed.
+        /// </summary>
+        public event EventHandler<DomMutatedEventArgs> DomMutated;
+
         /// <summary>
         /// Gets the read-only list of initialization scripts added for this JavaScript engine.
         /// </summary>
@@ -119,6 +129,30 @@ public void StopEventMonitoring()
             this.session.Value.Domains.JavaScript.BindingCalled -= OnScriptBindingCalled;
         }
 
+        /// <summary>
+        /// Enables monitoring for DOM changes.
+        /// </summary>
+        /// <returns>A task that represents the asynchronous operation.</returns>
+        public async Task EnableDomMutationMonitoring()
+        {
+            // Execute the script to have it enabled on the currently loaded page.
+            string script = GetMutationListenerScript();
+            await this.session.Value.Domains.JavaScript.Evaluate(script);
+
+            await this.AddScriptCallbackBinding(MonitorBindingName);
+            await this.AddInitializationScript(MonitorBindingName, script);
+        }
+
+        /// <summary>
+        /// Disables monitoring for DOM changes.
+        /// </summary>
+        /// <returns>A task that represents the asynchronous operation.</returns>
+        public async Task DisableDomMutationMonitoring()
+        {
+            await this.RemoveScriptCallbackBinding(MonitorBindingName);
+            await this.RemoveInitializationScript(MonitorBindingName);
+        }
+
         /// <summary>
         /// Asynchronously adds JavaScript to be loaded on every document load.
         /// </summary>
@@ -273,7 +307,7 @@ public async Task ClearAll()
         /// <returns>A task that represents the asynchronous operation.</returns>
         public async Task Reset()
         {
-            StopEventMonitoring();
+            this.StopEventMonitoring();
             await ClearAll();
         }
 
@@ -298,8 +332,34 @@ private async Task EnableDomains()
             }
         }
 
+        private string GetMutationListenerScript()
+        {
+            string listenerScript = string.Empty;
+            using (Stream resourceStream = ResourceUtilities.GetResourceStream("mutation-listener.js", "mutation-listener.js"))
+            {
+                using (StreamReader resourceReader = new StreamReader(resourceStream))
+                {
+                    listenerScript = resourceReader.ReadToEnd();
+                }
+            }
+
+            return listenerScript;
+        }
+
         private void OnScriptBindingCalled(object sender, BindingCalledEventArgs e)
         {
+            if (e.Name == MonitorBindingName)
+            {
+                DomMutationData valueChangeData = JsonConvert.DeserializeObject<DomMutationData>(e.Payload);
+                if (this.DomMutated != null)
+                {
+                    this.DomMutated(this, new DomMutatedEventArgs()
+                    {
+                        AttributeData = valueChangeData
+                    });
+                }
+            }
+
             if (this.JavaScriptCallbackExecuted != null)
             {
                 this.JavaScriptCallbackExecuted(this, new JavaScriptCallbackExecutedEventArgs()

dotnet/src/webdriver/WebDriver.csproj

@@ -119,6 +119,10 @@
       <Visible>False</Visible>
       <LogicalName>find-elements.js</LogicalName>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(ProjectDir)..\..\..\bazel-bin\javascript\cdp-support\mutation-listener.js">
+      <Visible>False</Visible>
+      <LogicalName>mutation-listener.js</LogicalName>
+    </EmbeddedResource>
   </ItemGroup>
 
   <ItemGroup Condition="'$(OS)' != 'WINDOWS_NT'">

javascript/cdp-support/BUILD.bazel

@@ -1,5 +1,6 @@
 package(default_visibility = [
     "//java/src/org/openqa/selenium/devtools:__pkg__",
+    "//dotnet/src/webdriver:__pkg__",
 ])
 
 exports_files([