.NET: Add github actions workflow for verify-samples (#5034)

* Add github actions workflow for verify-samples

* Make workflow run as part of PR (for now)

* Update workflow to remove pr trigger

* Address PR comments

dotnet/.github/skills/verify-samples-tool/SKILL.md

@@ -25,7 +25,7 @@ dotnet run --project eng/verify-samples -- Agent_Step02_StructuredOutput Agent_S
 dotnet run --project eng/verify-samples -- --parallel 8 --log results.log
 
 # Combine options
-dotnet run --project eng/verify-samples -- --category 03-workflows --parallel 4 --log results.log --csv results.csv
+dotnet run --project eng/verify-samples -- --category 03-workflows --parallel 4 --log results.log --csv results.csv --md results.md
 ```
 
 ### Required Environment Variables
@@ -40,6 +40,7 @@ Individual samples require their own env vars (e.g., `AZURE_AI_PROJECT_ENDPOINT`
 
 - `--log results.log` — detailed per-sample log with stdout/stderr, AI reasoning, and a summary
 - `--csv results.csv` — tabular summary with Sample, ProjectPath, Status, FailedChecks, and Failures columns
+- `--md results.md` — Markdown summary with results table and collapsible failure details (suitable for GitHub PR comments)
 
 ## Sample Categories
 

dotnet/eng/verify-samples/MarkdownResultWriter.cs

@@ -0,0 +1,98 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Text;
+
+namespace VerifySamples;
+
+/// <summary>
+/// Writes a Markdown summary of sample verification results.
+/// </summary>
+internal static class MarkdownResultWriter
+{
+    /// <summary>
+    /// Writes the results to a Markdown file at the specified path.
+    /// </summary>
+    public static async Task WriteAsync(
+        string path,
+        IReadOnlyList<VerificationResult> orderedResults,
+        IReadOnlyList<(string Name, string Reason)> skipped,
+        TimeSpan elapsed)
+    {
+        var passCount = orderedResults.Count(r => r.Passed);
+        var failCount = orderedResults.Count(r => !r.Passed);
+
+        var sb = new StringBuilder();
+        sb.AppendLine("# Sample Verification Results");
+        sb.AppendLine();
+        sb.AppendLine($"**{passCount} passed, {failCount} failed, {skipped.Count} skipped** | Elapsed: {elapsed.Hours:D2}:{elapsed.Minutes:D2}:{elapsed.Seconds:D2}");
+        sb.AppendLine();
+
+        // Results table
+        sb.AppendLine("| Sample | Status | Failed Checks | Failures |");
+        sb.AppendLine("|--------|--------|---------------|----------|");
+
+        foreach (var result in orderedResults)
+        {
+            var status = result.Passed ? "✅ PASSED" : "❌ FAILED";
+            var failedChecks = result.Failures.Count;
+            var failures = MdEscape(string.Join("; ", result.Failures));
+            sb.AppendLine($"| {MdEscape(result.SampleName)} | {status} | {failedChecks} | {failures} |");
+        }
+
+        foreach (var (name, reason) in skipped)
+        {
+            sb.AppendLine($"| {MdEscape(name)} | ⏭️ SKIPPED | 0 | {MdEscape(reason)} |");
+        }
+
+        // Collapsible AI reasoning details for failures
+        var failures2 = orderedResults.Where(r => !r.Passed && !string.IsNullOrEmpty(r.AIReasoning)).ToList();
+        if (failures2.Count > 0)
+        {
+            sb.AppendLine();
+            sb.AppendLine("## Failure Details");
+            sb.AppendLine();
+
+            foreach (var result in failures2)
+            {
+                sb.AppendLine($"<details><summary><strong>{HtmlEscape(result.SampleName)}</strong></summary>");
+                sb.AppendLine();
+                if (result.Failures.Count > 0)
+                {
+                    foreach (var failure in result.Failures)
+                    {
+                        sb.AppendLine($"- {MdEscape(failure)}");
+                    }
+
+                    sb.AppendLine();
+                }
+
+                sb.AppendLine("**AI Reasoning:**");
+                sb.AppendLine();
+                sb.AppendLine("```");
+                sb.AppendLine(result.AIReasoning);
+                sb.AppendLine("```");
+                sb.AppendLine();
+                sb.AppendLine("</details>");
+                sb.AppendLine();
+            }
+        }
+
+        await File.WriteAllTextAsync(path, sb.ToString());
+    }
+
+    /// <summary>
+    /// Escapes pipe characters and newlines for use inside Markdown table cells.
+    /// </summary>
+    private static string MdEscape(string value)
+    {
+        return value.Replace("|", "\\|").Replace("\n", " ").Replace("\r", "");
+    }
+
+    /// <summary>
+    /// Escapes HTML special characters for use inside HTML tags.
+    /// </summary>
+    private static string HtmlEscape(string value)
+    {
+        return value.Replace("&", "&amp;").Replace("<", "&lt;").Replace(">", "&gt;").Replace("\"", "&quot;");
+    }
+}

dotnet/eng/verify-samples/Program.cs

@@ -13,6 +13,7 @@
 //   dotnet run -- --parallel 16                         # Run up to 16 samples concurrently
 //   dotnet run -- --log results.log                     # Write sequential log to file
 //   dotnet run -- --csv results.csv                     # Write CSV summary to file
+//   dotnet run -- --md results.md                       # Write Markdown summary to file
 //
 // Required environment variables (for AI-powered samples):
 //   AZURE_OPENAI_ENDPOINT
@@ -90,6 +91,13 @@ try
         Console.WriteLine($"CSV written to: {options.CsvFilePath}");
     }
 
+    // Write Markdown summary
+    if (options.MarkdownFilePath is not null)
+    {
+        await MarkdownResultWriter.WriteAsync(options.MarkdownFilePath, orderedResults, run.Skipped, stopwatch.Elapsed);
+        Console.WriteLine($"Markdown written to: {options.MarkdownFilePath}");
+    }
+
     return orderedResults.Any(r => !r.Passed) ? 1 : 0;
 }
 finally

dotnet/eng/verify-samples/VerifyOptions.cs

@@ -17,6 +17,11 @@ internal sealed class VerifyOptions
     /// </summary>
     public string? CsvFilePath { get; init; }
 
+    /// <summary>
+    /// Path to write a Markdown summary file, or <c>null</c> to skip.
+    /// </summary>
+    public string? MarkdownFilePath { get; init; }
+
     /// <summary>
     /// Path to write a sequential log file, or <c>null</c> to skip.
     /// </summary>
@@ -49,6 +54,7 @@ internal sealed class VerifyOptions
         var categoryFilter = ExtractArg(argList, "--category");
         var logFilePath = ExtractArg(argList, "--log");
         var csvFilePath = ExtractArg(argList, "--csv");
+        var markdownFilePath = ExtractArg(argList, "--md");
 
         int maxParallelism = 8;
         var parallelArg = ExtractArg(argList, "--parallel");
@@ -98,6 +104,7 @@ internal sealed class VerifyOptions
             MaxParallelism = maxParallelism,
             LogFilePath = logFilePath,
             CsvFilePath = csvFilePath,
+            MarkdownFilePath = markdownFilePath,
             Samples = samples,
         };
     }