Complete and make ignitor more extensible (#11289)

* Add support for sending dotnet calls from "JS"
* Add support for acknowledging render batches.
* Extract logic into a separate BlazorClient class so that it can be reused.
* Support non prerendered pages.
* Allow reacting to incoming JSInterop calls.
* Allow reacting to incoming RenderBatch.

src/Components/test/testassets/Ignitor/BlazorClient.cs

@@ -0,0 +1,148 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Net.Http;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Components.Rendering;
+using Microsoft.AspNetCore.SignalR.Client;
+using Microsoft.AspNetCore.SignalR.Protocol;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Logging;
+
+namespace Ignitor
+{
+    public class BlazorClient
+    {
+        public BlazorClient()
+        {
+            CancellationTokenSource = new CancellationTokenSource();
+            TaskCompletionSource = new TaskCompletionSource<object>();
+
+            CancellationTokenSource.Token.Register(() =>
+            {
+                TaskCompletionSource.TrySetCanceled();
+            });
+        }
+
+        private CancellationTokenSource CancellationTokenSource { get; }
+        private CancellationToken CancellationToken => CancellationTokenSource.Token;
+        private TaskCompletionSource<object> TaskCompletionSource { get; }
+
+        public bool ConfirmRenderBatch { get; set; } = true;
+
+        public event Action<int, string, string> JSInterop;
+        public event Action<int, int, byte[]> RenderBatchReceived;
+
+        public string CircuitId { get; set; }
+
+        public HubConnection HubConnection { get; set; }
+
+        public Task ClickAsync(string elementId)
+        {
+            if (!Hive.TryFindElementById(elementId, out var elementNode))
+            {
+                throw new InvalidOperationException($"Could not find element with id {elementId}.");
+            }
+
+            return elementNode.ClickAsync(HubConnection);
+        }
+
+        public ElementHive Hive { get; set; }
+
+        public async Task<bool> ConnectAsync(Uri uri, bool prerendered)
+        {
+            var builder = new HubConnectionBuilder();
+            builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IHubProtocol, IgnitorMessagePackHubProtocol>());
+            builder.WithUrl(new Uri(uri, "_blazor/"));
+            builder.ConfigureLogging(l => l.AddConsole().SetMinimumLevel(LogLevel.Trace));
+            var hive = new ElementHive();
+
+            HubConnection = builder.Build();
+            await HubConnection.StartAsync(CancellationToken);
+            Console.WriteLine("Connected");
+
+            HubConnection.On<int, string, string>("JS.BeginInvokeJS", OnBeginInvokeJS);
+            HubConnection.On<int, int, byte[]>("JS.RenderBatch", OnRenderBatch);
+            HubConnection.On<Error>("JS.OnError", OnError);
+            HubConnection.Closed += OnClosedAsync;
+
+            // Now everything is registered so we can start the circuit.
+            if (prerendered)
+            {
+                CircuitId = await GetPrerenderedCircuitIdAsync(uri);
+                return await HubConnection.InvokeAsync<bool>("ConnectCircuit", CircuitId);
+            }
+            else
+            {
+                CircuitId = await HubConnection.InvokeAsync<string>("StartCircuit", uri, uri);
+                return CircuitId != null;
+            }
+
+            void OnBeginInvokeJS(int asyncHandle, string identifier, string argsJson)
+            {
+                JSInterop?.Invoke(asyncHandle, identifier, argsJson);
+            }
+
+            void OnRenderBatch(int browserRendererId, int batchId, byte[] batchData)
+            {
+                var batch = RenderBatchReader.Read(batchData);
+                hive.Update(batch);
+
+                if (ConfirmRenderBatch)
+                {
+                    HubConnection.InvokeAsync("OnRenderCompleted", batchId, /* error */ null);
+                }
+
+                RenderBatchReceived?.Invoke(browserRendererId, batchId, batchData);
+            }
+
+            void OnError(Error error)
+            {
+                Console.WriteLine("ERROR: " + error.Stack);
+            }
+
+            Task OnClosedAsync(Exception ex)
+            {
+                if (ex == null)
+                {
+                    TaskCompletionSource.TrySetResult(null);
+                }
+                else
+                {
+                    TaskCompletionSource.TrySetException(ex);
+                }
+
+                return Task.CompletedTask;
+            }
+        }
+
+        void InvokeDotNetMethod(object callId, string assemblyName, string methodIdentifier, object dotNetObjectId, string argsJson)
+        {
+            HubConnection.InvokeAsync("BeginInvokeDotNetFromJS", callId?.ToString(), assemblyName, methodIdentifier, dotNetObjectId ?? 0, argsJson);
+        }
+
+        private static async Task<string> GetPrerenderedCircuitIdAsync(Uri uri)
+        {
+            var httpClient = new HttpClient();
+            var response = await httpClient.GetAsync(uri);
+            var content = await response.Content.ReadAsStringAsync();
+
+            // <!-- M.A.C.Component:{"circuitId":"CfDJ8KZCIaqnXmdF...PVd6VVzfnmc1","rendererId":"0","componentId":"0"} -->
+            var match = Regex.Match(content, $"{Regex.Escape("<!-- M.A.C.Component:")}(.+?){Regex.Escape(" -->")}");
+            var json = JsonDocument.Parse(match.Groups[1].Value);
+            var circuitId = json.RootElement.GetProperty("circuitId").GetString();
+            return circuitId;
+        }
+
+        public void Cancel()
+        {
+            CancellationTokenSource.Cancel();
+            CancellationTokenSource.Dispose();
+        }
+    }
+}

src/Components/test/testassets/Ignitor/ComponentNode.cs

@@ -3,7 +3,7 @@
 
 namespace Ignitor
 {
-    internal class ComponentNode : ContainerNode
+    public class ComponentNode : ContainerNode
     {
         private readonly int _componentId;
 

src/Components/test/testassets/Ignitor/ContainerNode.cs

@@ -6,7 +6,7 @@ using System.Collections.Generic;
 
 namespace Ignitor
 {
-    internal abstract class ContainerNode : Node
+    public abstract class ContainerNode : Node
     {
         private readonly List<Node> _children;
 

src/Components/test/testassets/Ignitor/ElementHive.cs

@@ -8,7 +8,7 @@ using Microsoft.AspNetCore.Components.RenderTree;
 
 namespace Ignitor
 {
-    internal class ElementHive
+    public class ElementHive
     {
         private const string SelectValuePropname = "_blazorSelectValue";
 

src/Components/test/testassets/Ignitor/ElementNode.cs

@@ -11,7 +11,7 @@ using Microsoft.AspNetCore.SignalR.Client;
 
 namespace Ignitor
 {
-    internal class ElementNode : ContainerNode
+    public class ElementNode : ContainerNode
     {
         private readonly Dictionary<string, object> _attributes;
         private readonly Dictionary<string, object> _properties;
@@ -79,9 +79,9 @@ namespace Ignitor
         {
             if (!Events.TryGetValue("click", out var clickEventDescriptor))
             {
-                Console.WriteLine("Button does not have a click event. Exiting");
-                return;
+                throw new InvalidOperationException("Element does not have a click event.");
             }
+
             var mouseEventArgs = new UIMouseEventArgs()
             {
                 Type = clickEventDescriptor.EventName,

src/Components/test/testassets/Ignitor/Error.cs

@@ -0,0 +1,10 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Ignitor
+{
+    internal class Error
+    {
+        public string Stack { get; set; }
+    }
+}

src/Components/test/testassets/Ignitor/MarkupNode.cs

@@ -3,7 +3,7 @@
 
 namespace Ignitor
 {
-    internal class MarkupNode : Node
+    public class MarkupNode : Node
     {
         public MarkupNode(string markupContent)
         {

src/Components/test/testassets/Ignitor/Node.cs

@@ -3,7 +3,7 @@
 
 namespace Ignitor
 {
-    internal abstract class Node
+    public abstract class Node
     {
         public virtual ContainerNode Parent { get; set; }
     }

src/Components/test/testassets/Ignitor/Program.cs

@@ -30,13 +30,34 @@ namespace Ignitor
 
             var uri = new Uri(args[0]);
 
-            var program = new Program();
-            Console.CancelKeyPress += (sender, e) => { program.Cancel(); };
+            var client = new BlazorClient();
+            client.JSInterop += OnJSInterop;
+            Console.CancelKeyPress += (sender, e) => client.Cancel();
+
+            var done = new TaskCompletionSource<bool>(TaskCreationOptions.RunContinuationsAsynchronously);
+
+            // Click the counter button 1000 times
+            client.RenderBatchReceived += (int browserRendererId, int batchId, byte[] data) =>
+            {
+                if (batchId < 1000)
+                {
+                    client.ClickAsync("thecounter");
+                }
+                else
+                {
+                    done.TrySetResult(true);
+                }
+            };
+
+            await client.ConnectAsync(uri, prerendered: true);
+            await done.Task;
 
-            await program.ExecuteAsync(uri);
             return 0;
         }
 
+        private static void OnJSInterop(int callId, string identifier, string argsJson) =>
+            Console.WriteLine("JS Invoke: " + identifier + " (" + argsJson + ")");
+
         public Program()
         {
             CancellationTokenSource = new CancellationTokenSource();
@@ -54,14 +75,7 @@ namespace Ignitor
 
         public async Task ExecuteAsync(Uri uri)
         {
-            var httpClient = new HttpClient();
-            var response = await httpClient.GetAsync(uri);
-            var content = await response.Content.ReadAsStringAsync();
-
-            // <!-- M.A.C.Component:{"circuitId":"CfDJ8KZCIaqnXmdF...PVd6VVzfnmc1","rendererId":"0","componentId":"0"} -->
-            var match = Regex.Match(content, $"{Regex.Escape("<!-- M.A.C.Component:")}(.+?){Regex.Escape(" -->")}");
-            var json = JsonDocument.Parse(match.Groups[1].Value);
-            var circuitId = json.RootElement.GetProperty("circuitId").GetString();
+            string circuitId = await GetPrerenderedCircuitId(uri);
 
             var builder = new HubConnectionBuilder();
             builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IHubProtocol, IgnitorMessagePackHubProtocol>());
@@ -117,6 +131,19 @@ namespace Ignitor
             }
         }
 
+        private static async Task<string> GetPrerenderedCircuitId(Uri uri)
+        {
+            var httpClient = new HttpClient();
+            var response = await httpClient.GetAsync(uri);
+            var content = await response.Content.ReadAsStringAsync();
+
+            // <!-- M.A.C.Component:{"circuitId":"CfDJ8KZCIaqnXmdF...PVd6VVzfnmc1","rendererId":"0","componentId":"0"} -->
+            var match = Regex.Match(content, $"{Regex.Escape("<!-- M.A.C.Component:")}(.+?){Regex.Escape(" -->")}");
+            var json = JsonDocument.Parse(match.Groups[1].Value);
+            var circuitId = json.RootElement.GetProperty("circuitId").GetString();
+            return circuitId;
+        }
+
         private static async Task ClickAsync(string id, ElementHive hive, HubConnection connection)
         {
             if (!hive.TryFindElementById(id, out var elementNode))
@@ -133,10 +160,5 @@ namespace Ignitor
             CancellationTokenSource.Cancel();
             CancellationTokenSource.Dispose();
         }
-
-        private class Error
-        {
-            public string Stack { get; set; }
-        }
     }
 }

src/Components/test/testassets/Ignitor/TextNode.cs

@@ -3,7 +3,7 @@
 
 namespace Ignitor
 {
-    internal class TextNode : Node
+    public class TextNode : Node
     {
         public TextNode(string text)
         {