Add Microsoft.Testing.Extensions.HtmlReport extension

TestFx.slnx

@@ -41,6 +41,7 @@
     <Project Path="src/Platform/Microsoft.Testing.Extensions.CrashDump/Microsoft.Testing.Extensions.CrashDump.csproj" />
     <Project Path="src/Platform/Microsoft.Testing.Extensions.HangDump/Microsoft.Testing.Extensions.HangDump.csproj" />
     <Project Path="src/Platform/Microsoft.Testing.Extensions.HotReload/Microsoft.Testing.Extensions.HotReload.csproj" />
+    <Project Path="src/Platform/Microsoft.Testing.Extensions.HtmlReport/Microsoft.Testing.Extensions.HtmlReport.csproj" />
     <Project Path="src/Platform/Microsoft.Testing.Extensions.MSBuild/Microsoft.Testing.Extensions.MSBuild.csproj" />
     <Project Path="src/Platform/Microsoft.Testing.Extensions.OpenTelemetry/Microsoft.Testing.Extensions.OpenTelemetry.csproj" />
     <Project Path="src/Platform/Microsoft.Testing.Extensions.Retry/Microsoft.Testing.Extensions.Retry.csproj" />

src/Platform/Microsoft.Testing.Extensions.HtmlReport/BannedSymbols.txt

@@ -0,0 +1,9 @@
+P:System.DateTime.Now; Use 'IClock' instead
+P:System.DateTime.UtcNow; Use 'IClock' instead
+M:System.Threading.Tasks.Task.Run(System.Action); Use 'ITask' instead
+M:System.Threading.Tasks.Task.WhenAll(System.Threading.Tasks.Task[]); Use 'ITask' instead
+M:System.Threading.Tasks.Task.WhenAll(System.Collections.Generic.IEnumerable{System.Threading.Tasks.Task}); Use 'ITask' instead
+M:System.String.IsNullOrEmpty(System.String); Use 'RoslynString.IsNullOrEmpty' instead
+M:System.String.IsNullOrWhiteSpace(System.String); Use 'RoslynString.IsNullOrWhiteSpace' instead
+M:System.Diagnostics.Debug.Assert(System.Boolean); Use 'RoslynDebug.Assert' instead
+M:System.Diagnostics.Debug.Assert(System.Boolean,System.String); Use 'RoslynDebug.Assert' instead

src/Platform/Microsoft.Testing.Extensions.HtmlReport/CapturedTestResult.cs

@@ -0,0 +1,40 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.Testing.Extensions.HtmlReport;
+
+// Minimal capped-size projection of a TestNodeUpdateMessage. The consumer projects
+// each message into this DTO immediately so that we don't retain entire test nodes
+// (and their potentially huge stdout/stderr/stack trace strings) in memory for the
+// whole session. All variable-length text fields are already truncated at this point
+// so the engine doesn't need to truncate again.
+internal sealed class CapturedTestResult
+{
+    public required string Uid { get; init; }
+
+    public required string DisplayName { get; init; }
+
+    public required string Outcome { get; init; }
+
+    public required TimeSpan Duration { get; init; }
+
+    public DateTimeOffset? StartTime { get; init; }
+
+    public DateTimeOffset? EndTime { get; init; }
+
+    public string? ClassName { get; init; }
+
+    public string? MethodName { get; init; }
+
+    public string? ErrorMessage { get; init; }
+
+    public string? ExceptionType { get; init; }
+
+    public string? StackTrace { get; init; }
+
+    public string? StandardOutput { get; init; }
+
+    public string? StandardError { get; init; }
+
+    public IReadOnlyList<KeyValuePair<string, string>>? Traits { get; init; }
+}