Replace Verify with in-house generator snapshot assertions

.github/dependabot.yml

@@ -15,7 +15,6 @@ updates:
         patterns:
           - "NUnit*"
           - "coverlet*"
-          - "Verify*"
 
   - package-ecosystem: github-actions
     directory: /

Directory.Packages.props

@@ -33,9 +33,6 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.9.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="5.9.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.9.0" />
-    <!-- Source Generator Testing -->
-    <PackageVersion Include="Verify.SourceGenerators" Version="2.5.0" />
-    <PackageVersion Include="Verify.NUnit" Version="31.28.0" />
     <!-- Analyzer Testing (pinned to match Microsoft.CodeAnalysis.CSharp 5.0.0) -->
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.4" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="1.1.4" />

tests/SharpDicom.Codecs.Tests/NativeCodecsTests.cs

@@ -428,8 +428,8 @@ public void NativeCodecOptions_CanSetAllProperties()
         [Test]
         public void Initialize_WithEnableOptions_SetsProperties()
         {
-            // Note: Enable options are only applied during successful initialization
-            // When native library is unavailable, options aren't applied after DllNotFoundException
+            // Enable options are applied before the native library is probed,
+            // so they take effect whether or not the library loads
             NativeCodecs.Initialize(new NativeCodecOptions
             {
                 SuppressInitializationErrors = true,
@@ -439,23 +439,10 @@ public void Initialize_WithEnableOptions_SetsProperties()
                 EnableVideo = false
             });
 
-            // If native library was loaded successfully, enable options should be set
-            if (NativeCodecs.IsAvailable)
-            {
-                Assert.That(NativeCodecs.EnableJpeg, Is.False);
-                Assert.That(NativeCodecs.EnableJpeg2000, Is.False);
-                Assert.That(NativeCodecs.EnableJpegLs, Is.False);
-                Assert.That(NativeCodecs.EnableVideo, Is.False);
-            }
-            else
-            {
-                // When library unavailable, options weren't applied - properties remain default
-                // This is a design limitation when native libraries are missing
-                Assert.That(NativeCodecs.EnableJpeg, Is.True, "Default value when library unavailable");
-                Assert.That(NativeCodecs.EnableJpeg2000, Is.True, "Default value when library unavailable");
-                Assert.That(NativeCodecs.EnableJpegLs, Is.True, "Default value when library unavailable");
-                Assert.That(NativeCodecs.EnableVideo, Is.True, "Default value when library unavailable");
-            }
+            Assert.That(NativeCodecs.EnableJpeg, Is.False);
+            Assert.That(NativeCodecs.EnableJpeg2000, Is.False);
+            Assert.That(NativeCodecs.EnableJpegLs, Is.False);
+            Assert.That(NativeCodecs.EnableVideo, Is.False);
         }
 
         #endregion

tests/SharpDicom.Tests.Polyfills/SharpDicom.Tests.Polyfills.csproj

@@ -18,8 +18,6 @@
     <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" />
 
     <!-- Source Generator Testing -->
-    <PackageReference Include="Verify.SourceGenerators" />
-    <PackageReference Include="Verify.NUnit" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" />
   </ItemGroup>
@@ -30,8 +28,13 @@
     <ProjectReference Include="..\..\src\SharpDicom.Generators\SharpDicom.Generators.csproj" />
   </ItemGroup>
 
-  <!-- Share test source files from main test project, excluding obj/bin and NET5+ only tests -->
+  <!-- Share test source files from main test project, excluding obj/bin, generator snapshots and NET5+ only tests -->
   <ItemGroup>
-    <Compile Include="..\SharpDicom.Tests\**\*.cs" Exclude="..\SharpDicom.Tests\obj\**;..\SharpDicom.Tests\bin\**;..\SharpDicom.Tests\Cli\**;..\SharpDicom.Tests\Benchmarks\**;..\SharpDicom.Tests\Deidentification\DeidentificationConfigLoaderTests.cs;..\SharpDicom.Tests\Deidentification\DeidentificationIntegrationTests.cs;..\SharpDicom.Tests\Deidentification\BatchDeidentifierTests.cs;..\SharpDicom.Tests\Deidentification\DeidentificationApiSmokeTests.cs;..\SharpDicom.Tests\Network\Tls\TlsServerOptionsTests.cs;..\SharpDicom.Tests\Network\Tls\TlsIntegrationTests.cs" LinkBase="Tests" />
+    <Compile Include="..\SharpDicom.Tests\**\*.cs" Exclude="..\SharpDicom.Tests\obj\**;..\SharpDicom.Tests\bin\**;..\SharpDicom.Tests\Cli\**;..\SharpDicom.Tests\Benchmarks\**;..\SharpDicom.Tests\Deidentification\DeidentificationConfigLoaderTests.cs;..\SharpDicom.Tests\Deidentification\DeidentificationIntegrationTests.cs;..\SharpDicom.Tests\Deidentification\BatchDeidentifierTests.cs;..\SharpDicom.Tests\Deidentification\DeidentificationApiSmokeTests.cs;..\SharpDicom.Tests\Network\Tls\TlsServerOptionsTests.cs;..\SharpDicom.Tests\Network\Tls\TlsIntegrationTests.cs;..\SharpDicom.Tests\**\*.verified.cs;..\SharpDicom.Tests\**\*.received.cs" LinkBase="Tests" />
+  </ItemGroup>
+
+  <!-- Repository root for resolving generator snapshot paths when CI maps source paths to /_/ -->
+  <ItemGroup>
+    <AssemblyMetadata Include="RepositoryRoot" Value="$([System.IO.Path]::GetFullPath('$(MSBuildThisFileDirectory)../../'))" />
   </ItemGroup>
 </Project>

tests/SharpDicom.Tests/Generators/DicomDictionaryGeneratorTests.cs

@@ -1,21 +1,19 @@
 using System.Collections.Immutable;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using NUnit.Framework;
 using SharpDicom.Generators;
-using VerifyNUnit;
 
 namespace SharpDicom.Tests.Generators;
 
 /// <summary>
-/// Snapshot tests for the DicomDictionaryGenerator using Verify.SourceGenerators.
+/// Snapshot tests for the DicomDictionaryGenerator.
 /// </summary>
 [TestFixture]
 public class DicomDictionaryGeneratorTests
 {
     [Test]
-    public Task GeneratesTagsFromMinimalXml()
+    public void GeneratesTagsFromMinimalXml()
     {
         // Minimal Part 6-like XML with one tag
         var xml = """
@@ -39,11 +37,11 @@ public Task GeneratesTagsFromMinimalXml()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task GeneratesMultiVRTag()
+    public void GeneratesMultiVRTag()
     {
         // Tag with multiple VRs (US or SS)
         var xml = """
@@ -67,11 +65,11 @@ public Task GeneratesMultiVRTag()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task GeneratesRetiredTag()
+    public void GeneratesRetiredTag()
     {
         // Retired tag (should be marked with IsRetired=true)
         var xml = """
@@ -95,11 +93,11 @@ public Task GeneratesRetiredTag()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task GeneratesUIDs()
+    public void GeneratesUIDs()
     {
         // UID registry table
         var xml = """
@@ -129,11 +127,11 @@ public Task GeneratesUIDs()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task HandlesMaskedTag()
+    public void HandlesMaskedTag()
     {
         // Masked tag (50xx,0010)
         var xml = """
@@ -157,31 +155,31 @@ public Task HandlesMaskedTag()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task HandlesEmptyXml()
+    public void HandlesEmptyXml()
     {
         var xml = """
             <?xml version="1.0" encoding="UTF-8"?>
             <book xmlns="http://docbook.org/ns/docbook">
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task ReportsDiagnosticForInvalidXml()
+    public void ReportsDiagnosticForInvalidXml()
     {
         var xml = "not valid xml";
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
     [Test]
-    public Task GeneratesTagsAndUIDsCombined()
+    public void GeneratesTagsAndUIDsCombined()
     {
         // Combined tags and UIDs in same XML
         var xml = """
@@ -217,10 +215,10 @@ public Task GeneratesTagsAndUIDsCombined()
             </book>
             """;
 
-        return VerifyGenerator(xml, "part06.xml");
+        VerifyGenerator(xml, "part06.xml");
     }
 
-    private static Task VerifyGenerator(string xmlContent, string fileName)
+    private static void VerifyGenerator(string xmlContent, string fileName)
     {
         // Create compilation
         // IL3000: Assembly.Location is required for source generator tests to get metadata references
@@ -246,6 +244,6 @@ private static Task VerifyGenerator(string xmlContent, string fileName)
         driver = driver.RunGenerators(compilation);
 
         // Verify snapshot
-        return Verifier.Verify(driver);
+        GeneratorSnapshot.Verify(driver);
     }
 }

tests/SharpDicom.Tests/Generators/GeneratorSnapshot.cs

@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Text;
+using Microsoft.CodeAnalysis;
+using NUnit.Framework;
+
+namespace SharpDicom.Tests.Generators;
+
+/// <summary>
+/// Snapshot assertions for source generator output.
+/// </summary>
+/// <remarks>
+/// Each generated source is compared against
+/// <c>{TestClass}.{TestMethod}#{HintName}.verified.cs</c> next to the calling test file.
+/// On mismatch a <c>.received.cs</c> file is written alongside for review; accept a change
+/// by renaming it to <c>.verified.cs</c>.
+/// </remarks>
+internal static class GeneratorSnapshot
+{
+    private static readonly UTF8Encoding Utf8WithBom = new(encoderShouldEmitUTF8Identifier: true);
+
+    /// <summary>
+    /// Asserts that the generator run produced no diagnostics or exceptions and that
+    /// its output matches the verified snapshots for the current test.
+    /// </summary>
+    /// <param name="driver">The generator driver after <c>RunGenerators</c>.</param>
+    /// <param name="callerFilePath">Path of the calling test file (supplied by the compiler).</param>
+    public static void Verify(GeneratorDriver driver, [CallerFilePath] string callerFilePath = "")
+    {
+        var runResult = driver.GetRunResult();
+        var exceptions = runResult.Results.Where(r => r.Exception is not null).Select(r => r.Exception!.ToString());
+        Assert.That(exceptions, Is.Empty, "Generator threw an exception");
+        Assert.That(runResult.Diagnostics.Select(d => d.ToString()), Is.Empty, "Generator reported diagnostics");
+
+        var directory = Path.GetDirectoryName(ResolveSourcePath(callerFilePath))!;
+        var test = TestContext.CurrentContext.Test;
+        var className = test.ClassName!.Substring(test.ClassName.LastIndexOf('.') + 1);
+        var prefix = $"{className}.{test.MethodName}#";
+
+        var failures = new List<string>();
+        var expectedFiles = new HashSet<string>(StringComparer.Ordinal);
+
+        foreach (var generated in runResult.Results.SelectMany(r => r.GeneratedSources))
+        {
+            var baseName = prefix + Path.GetFileNameWithoutExtension(generated.HintName);
+            var verifiedPath = Path.Combine(directory, baseName + ".verified.cs");
+            var receivedPath = Path.Combine(directory, baseName + ".received.cs");
+            expectedFiles.Add(Path.GetFileName(verifiedPath));
+
+            var actual = Normalize($"//HintName: {generated.HintName}\n{generated.SourceText}");
+            var expected = File.Exists(verifiedPath) ? Normalize(File.ReadAllText(verifiedPath)) : null;
+
+            if (actual == expected)
+            {
+                if (File.Exists(receivedPath))
+                {
+                    File.Delete(receivedPath);
+                }
+
+                continue;
+            }
+
+            File.WriteAllText(receivedPath, actual + "\n", Utf8WithBom);
+            failures.Add(expected is null
+                ? $"Missing snapshot {Path.GetFileName(verifiedPath)}; wrote {Path.GetFileName(receivedPath)}"
+                : $"Snapshot mismatch for {Path.GetFileName(verifiedPath)}; wrote {Path.GetFileName(receivedPath)}");
+        }
+
+        foreach (var stale in Directory.GetFiles(directory, prefix + "*.verified.cs"))
+        {
+            if (!expectedFiles.Contains(Path.GetFileName(stale)))
+            {
+                failures.Add($"Snapshot {Path.GetFileName(stale)} has no corresponding generated source");
+            }
+        }
+
+        Assert.That(failures, Is.Empty, "Generator output does not match snapshots");
+    }
+
+    /// <summary>
+    /// Maps a compiler-recorded source path back to the local file system. Deterministic
+    /// CI builds record source paths under <c>/_/</c> rather than the real repository root.
+    /// </summary>
+    private static string ResolveSourcePath(string callerFilePath)
+    {
+        const string MappedRoot = "/_/";
+
+        if (File.Exists(callerFilePath) || !callerFilePath.StartsWith(MappedRoot, StringComparison.Ordinal))
+        {
+            return callerFilePath;
+        }
+
+        var repositoryRoot = typeof(GeneratorSnapshot).Assembly
+            .GetCustomAttributes<AssemblyMetadataAttribute>()
+            .Single(a => a.Key == "RepositoryRoot")
+            .Value!;
+
+        return Path.Combine(repositoryRoot, callerFilePath.Substring(MappedRoot.Length));
+    }
+
+    private static string Normalize(string text) =>
+        text.TrimStart('').Replace("\r\n", "\n").TrimEnd();
+}