VerifyTests · SimonCropp · Aug 14, 2026 · Aug 14, 2026
diff --git a/src/DiffEngine.Tests/InlineApplierTests.cs b/src/DiffEngine.Tests/InlineApplierTests.cs
@@ -25,13 +25,26 @@ static byte[] Utf8(string text, bool bom)
 
     const string source = "class C\n{\n    void M() => Verify(value).Snapshot(\"old\");\n}";
 
+    // Nothing here queues a patch, so none of them has a reviewable identity. Stated once rather
+    // than at every call site below.
+    static InlinePatch Patch(
+        string sourceFile,
+        int lineHint,
+        string? originalExpression,
+        string newContent,
+        InlinePatchMode mode = InlinePatchMode.Set) =>
+        new(sourceFile, lineHint, originalExpression, newContent, mode)
+        {
+            TestName = null
+        };
+
     [Test]
     public async Task Utf8BomPreserved()
     {
         var path = WriteTemp(Utf8(source, bom: true));
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "new"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "new"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             var bytes = await File.ReadAllBytesAsync(path);
             await Assert.That(bytes[0]).IsEqualTo((byte)0xEF);
@@ -51,7 +64,7 @@ public async Task NoBomStaysNoBom()
         var path = WriteTemp(Utf8(source, bom: false));
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "new"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "new"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             var bytes = await File.ReadAllBytesAsync(path);
             await Assert.That(bytes[0]).IsEqualTo((byte)'c');
@@ -69,7 +82,7 @@ public async Task Utf16Preserved()
         var path = WriteTemp([.. encoding.GetPreamble(), .. encoding.GetBytes(source)]);
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "new"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "new"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             var bytes = await File.ReadAllBytesAsync(path);
             await Assert.That(bytes[0]).IsEqualTo((byte)0xFF);
@@ -96,7 +109,7 @@ .. Utf8("class C\n{\n    // caf", bom: false),
         var path = WriteTemp(bytes);
         try
         {
-            var result = InlineApplier.Apply(new(path, 4, "\"old\"", "new"));
+            var result = InlineApplier.Apply(Patch(path, 4, "\"old\"", "new"));
 
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Failed);
             await Assert.That(result.Message!).Contains("Convert it to UTF-8");
@@ -115,7 +128,7 @@ public async Task NonAsciiUtf8IsPreserved()
         var path = WriteTemp(Utf8(text, bom: false));
         try
         {
-            var result = InlineApplier.Apply(new(path, 4, "\"old\"", "naïve ☕"));
+            var result = InlineApplier.Apply(Patch(path, 4, "\"old\"", "naïve ☕"));
 
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             var after = await File.ReadAllTextAsync(path);
@@ -134,7 +147,7 @@ public async Task CrlfPreserved()
         var path = WriteTemp(Utf8(source.Replace("\n", "\r\n"), bom: false));
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "a\nb"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "a\nb"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             var text = await File.ReadAllTextAsync(path);
             await Assert.That(text).DoesNotContain("a\nb");
@@ -163,7 +176,7 @@ public async Task EolAndBomCombinations(string fileEol, string contentEol, bool
         try
         {
             var content = "a" + contentEol + "b";
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", content));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", content));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
 
             var bytes = await File.ReadAllBytesAsync(path);
@@ -202,7 +215,7 @@ public async Task LfFileIsNotConvertedToCrlf()
         var path = WriteTemp(Utf8(source, bom: false));
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "a\nb"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "a\nb"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Applied);
             await Assert.That(await File.ReadAllTextAsync(path)).DoesNotContain("\r");
         }
@@ -217,7 +230,7 @@ public async Task LfFileIsNotConvertedToCrlf()
     [Test]
     public async Task TryParseToleratesLeadingBom()
     {
-        var patch = new InlinePatch(@"C:\proj\Tests.cs", 7, "\"old\"", "new content");
+        var patch = Patch(@"C:\proj\Tests.cs", 7, "\"old\"", "new content");
         var payload = "" + InlinePatchFile.Build(patch);
 
         var read = InlinePatchFile.TryParse(payload, out var result);
@@ -231,7 +244,7 @@ public async Task TryParseToleratesLeadingBom()
     [Test]
     public async Task MissingFileFails()
     {
-        var result = InlineApplier.Apply(new(Path.Combine(Path.GetTempPath(), "does-not-exist-inline.cs"), 1, null, "x"));
+        var result = InlineApplier.Apply(Patch(Path.Combine(Path.GetTempPath(), "does-not-exist-inline.cs"), 1, null, "x"));
         await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.Failed);
     }
 
@@ -242,7 +255,7 @@ public async Task AlreadyAppliedDoesNotWrite()
         try
         {
             var before = File.GetLastWriteTimeUtc(path);
-            var result = InlineApplier.Apply(new(path, 3, "\"old\"", "old"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"old\"", "old"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.AlreadyApplied);
             await Assert.That(File.GetLastWriteTimeUtc(path)).IsEqualTo(before);
         }
@@ -259,8 +272,8 @@ public async Task ParallelAppliesToSameFile()
         var path = WriteTemp(Utf8(multi, bom: false));
         try
         {
-            var taskA = Task.Run(() => InlineApplier.Apply(new(path, 3, "\"oldA\"", "newA")));
-            var taskB = Task.Run(() => InlineApplier.Apply(new(path, 4, "\"oldB\"", "newB")));
+            var taskA = Task.Run(() => InlineApplier.Apply(Patch(path, 3, "\"oldA\"", "newA")));
+            var taskB = Task.Run(() => InlineApplier.Apply(Patch(path, 4, "\"oldB\"", "newB")));
             var results = await Task.WhenAll(taskA, taskB);
             await Assert.That(results[0].Status).IsEqualTo(InlineApplyStatus.Applied);
             await Assert.That(results[1].Status).IsEqualTo(InlineApplyStatus.Applied);
@@ -300,8 +313,8 @@ public async Task ParallelAppliesWithIdenticalLiterals()
         var path = WriteTemp(Utf8(multi, bom: false));
         try
         {
-            var taskA = Task.Run(() => InlineApplier.Apply(new(path, 3, "\"old\"", "same")));
-            var taskB = Task.Run(() => InlineApplier.Apply(new(path, 4, "\"old\"", "same")));
+            var taskA = Task.Run(() => InlineApplier.Apply(Patch(path, 3, "\"old\"", "same")));
+            var taskB = Task.Run(() => InlineApplier.Apply(Patch(path, 4, "\"old\"", "same")));
             var results = await Task.WhenAll(taskA, taskB);
 
             await Assert.That(results[0].Status).IsEqualTo(InlineApplyStatus.Applied);
@@ -324,8 +337,8 @@ public async Task SequentialAppliesWithIdenticalLiterals()
         var path = WriteTemp(Utf8(multi, bom: false));
         try
         {
-            var first = InlineApplier.Apply(new(path, 3, "\"old\"", "newA"));
-            var second = InlineApplier.Apply(new(path, 4, "\"old\"", "newB"));
+            var first = InlineApplier.Apply(Patch(path, 3, "\"old\"", "newA"));
+            var second = InlineApplier.Apply(Patch(path, 4, "\"old\"", "newB"));
 
             await Assert.That(first.Status).IsEqualTo(InlineApplyStatus.Applied);
             await Assert.That(second.Status).IsEqualTo(InlineApplyStatus.Applied);
@@ -351,7 +364,7 @@ public async Task NotFoundWhenSourceChanged()
         var path = WriteTemp(Utf8(source, bom: false));
         try
         {
-            var result = InlineApplier.Apply(new(path, 3, "\"gone-expression\"", "new"));
+            var result = InlineApplier.Apply(Patch(path, 3, "\"gone-expression\"", "new"));
             await Assert.That(result.Status).IsEqualTo(InlineApplyStatus.NotFound);
             await Assert.That(result.Message!).Contains("Re-run the test");
         }
@@ -367,7 +380,10 @@ public class InlinePatchFileTests
     [Test]
     public async Task RoundTrip()
     {
-        var patch = new InlinePatch(@"C:\proj\Tests.cs", 42, "\"\"\"\nold\n\"\"\"", "line1\nline2");
+        var patch = new InlinePatch(@"C:\proj\Tests.cs", 42, "\"\"\"\nold\n\"\"\"", "line1\nline2")
+        {
+            TestName = null
+        };
         var path = Path.Combine(Path.GetTempPath(), $"InlinePatchFileTests_{Guid.NewGuid():N}.inlinepatch");
         try
         {
@@ -388,7 +404,10 @@ public async Task RoundTrip()
     [Test]
     public async Task RoundTripNullExpression()
     {
-        var patch = new InlinePatch("Tests.cs", 1, null, "content");
+        var patch = new InlinePatch("Tests.cs", 1, null, "content")
+        {
+            TestName = null
+        };
         var path = Path.Combine(Path.GetTempPath(), $"InlinePatchFileTests_{Guid.NewGuid():N}.inlinepatch");
         try
         {
@@ -409,7 +428,10 @@ public async Task RoundTripNullExpression()
     [Arguments(InlinePatchMode.Remove)]
     public async Task RoundTripMode(InlinePatchMode mode)
     {
-        var patch = new InlinePatch("Tests.cs", 1, null, "content", mode);
+        var patch = new InlinePatch("Tests.cs", 1, null, "content", mode)
+        {
+            TestName = null
+        };
 
         var read = InlinePatchFile.TryParse(InlinePatchFile.Build(patch), out var result);
 
@@ -420,7 +442,7 @@ public async Task RoundTripMode(InlinePatchMode mode)
     [Test]
     public async Task DefaultModeIsSet()
     {
-        var read = InlinePatchFile.TryParse(InlinePatchFile.Build(new("Tests.cs", 1, null, "content")), out var result);
+        var read = InlinePatchFile.TryParse(InlinePatchFile.Build(new("Tests.cs", 1, null, "content") { TestName = null }), out var result);
 
         await Assert.That(read).IsTrue();
         await Assert.That(result!.Mode).IsEqualTo(InlinePatchMode.Set);
@@ -481,7 +503,7 @@ public async Task MetadataRoundTrips()
     [Test]
     public async Task NullMetadataRoundTripsAsNull()
     {
-        var read = InlinePatchFile.TryParse(InlinePatchFile.Build(new("Tests.cs", 1, null, "content")), out var result);
+        var read = InlinePatchFile.TryParse(InlinePatchFile.Build(new("Tests.cs", 1, null, "content") { TestName = null }), out var result);
 
         await Assert.That(read).IsTrue();
         await Assert.That(result!.TestName).IsNull();
@@ -533,7 +555,7 @@ public async Task MetadataOrderIsFlexible()
     [Test]
     public async Task UnknownTrailingLinesAreIgnored()
     {
-        var payload = InlinePatchFile.Build(new("Tests.cs", 1, null, "content")) + "future: value\n";
+        var payload = InlinePatchFile.Build(new("Tests.cs", 1, null, "content") { TestName = null }) + "future: value\n";
 
         var read = InlinePatchFile.TryParse(payload, out var result);
 

diff --git a/src/DiffEngine.Tests/InlineQueueTests.cs b/src/DiffEngine.Tests/InlineQueueTests.cs
@@ -5,10 +5,16 @@
 /// </summary>
 public class InlineQueueTests
 {
-    static InlinePatch Patch(string source = "Sample.cs", int line = 42, string content = "new", string? framework = null) =>
+    static InlinePatch Patch(
+        string source = "Sample.cs",
+        int line = 42,
+        string content = "new",
+        string? framework = null,
+        string? testName = null) =>
         new(source, line, "\"old\"", content)
         {
-            Framework = framework
+            Framework = framework,
+            TestName = testName
         };
 
     static InlineApplyResult Fails(InlinePatch patch) =>

diff --git a/src/DiffEngine.Tests/ViewerProtocolTests.cs b/src/DiffEngine.Tests/ViewerProtocolTests.cs
@@ -10,10 +10,25 @@
 /// </summary>
 public class ViewerProtocolTests
 {
+    // These pin the wire shape rather than what a reviewer reads, so nothing here is named. The
+    // one test that is about the name says so itself.
+    static InlinePatch Patch(
+        string source,
+        int line,
+        string? expression,
+        string content,
+        InlinePatchMode mode = InlinePatchMode.Set,
+        string? framework = null) =>
+        new(source, line, expression, content, mode)
+        {
+            TestName = null,
+            Framework = framework
+        };
+
     [Test]
     public async Task InlineMessageRoundTrips()
     {
-        var patch = new InlinePatch("Tests.cs", 42, "\"old\"", "new content");
+        var patch = Patch("Tests.cs", 42, "\"old\"", "new content");
 
         var payload = new ViewerMessage(ViewerVerb.Inline, Body: InlinePatchFile.Build(patch)).Build();
 
@@ -33,7 +48,7 @@ public async Task InlineMessageRoundTrips()
     public async Task AwkwardSnapshotTextSurvivesTheRoundTrip()
     {
         var content = "line \"one\"\n\tbraces {} and | pipes\r\nversion: 1\nverb: quit\n";
-        var patch = new InlinePatch("Tests.cs", 1, null, content);
+        var patch = Patch("Tests.cs", 1, null, content);
 
         var payload = new ViewerMessage(ViewerVerb.Inline, Body: InlinePatchFile.Build(patch)).Build();
 
@@ -53,7 +68,7 @@ public async Task EveryModeRoundTrips()
         foreach (var name in Enum.GetNames(typeof(InlinePatchMode)))
         {
             var mode = (InlinePatchMode) Enum.Parse(typeof(InlinePatchMode), name);
-            var patch = new InlinePatch("Tests.cs", 1, null, "content", mode);
+            var patch = Patch("Tests.cs", 1, null, "content", mode);
             var payload = new ViewerMessage(ViewerVerb.Inline, Body: InlinePatchFile.Build(patch)).Build();
 
             await Assert.That(ViewerMessage.TryParse(payload, out var message)).IsTrue();
@@ -151,7 +166,7 @@ public async Task AListingItemCarriesKeyNameAndStatus()
     [Test]
     public async Task AFullListingRoundTripsThePatch()
     {
-        var patch = new InlinePatch("Tests.cs", 42, "\"old\"", "new content");
+        var patch = Patch("Tests.cs", 42, "\"old\"", "new content");
         var listing = ViewerResponse.Listing(
         [
             new("tests.cs|42", "Tests.cs:42", "locked", InlinePatchFile.Build(patch))
@@ -174,7 +189,7 @@ public async Task AFullListingRoundTripsThePatch()
     [Test]
     public async Task AFullListingHasNoItemLines()
     {
-        var patch = InlinePatchFile.Build(new("Tests.cs", 1, null, "content"));
+        var patch = InlinePatchFile.Build(Patch("Tests.cs", 1, null, "content"));
         var text = ViewerResponse.Listing([new("key", "Tests.cs:1", null, patch)]).Build();
 
         await Assert.That(Fields(text, "item: ")).IsEmpty();
@@ -214,7 +229,7 @@ public async Task SettleCarriesTheOriginInTheBody()
     [Test]
     public async Task AFullListingCarriesThePrimaryOrigins()
     {
-        var patch = InlinePatchFile.Build(new("Tests.cs", 42, "\"old\"", "new content"));
+        var patch = InlinePatchFile.Build(Patch("Tests.cs", 42, "\"old\"", "new content"));
         var listing = ViewerResponse.Listing(
         [
             new("tests.cs|42", "Tests.cs:42", null, patch)
@@ -236,8 +251,8 @@ public async Task AFullListingCarriesThePrimaryOrigins()
     [Test]
     public async Task AVariantLineRoundTrips()
     {
-        var primary = InlinePatchFile.Build(new("Tests.cs", 42, "\"old\"", "eight"));
-        var other = InlinePatchFile.Build(new("Tests.cs", 42, "\"old\"", "nine"));
+        var primary = InlinePatchFile.Build(Patch("Tests.cs", 42, "\"old\"", "eight"));
+        var other = InlinePatchFile.Build(Patch("Tests.cs", 42, "\"old\"", "nine"));
         var listing = ViewerResponse.Listing(
         [
             new("tests.cs|42", "Tests.cs:42", null, primary)
@@ -338,8 +353,8 @@ public async Task TrackedKeysCannotCollideWithInlineKeys()
     [Test]
     public async Task AConflictedEntryListsItsStatus()
     {
-        var eight = new InlinePatch("Tests.cs", 42, "\"old\"", "eight") { Framework = "net8.0" };
-        var nine = new InlinePatch("Tests.cs", 42, "\"old\"", "nine") { Framework = "net9.0" };
+        var eight = Patch("Tests.cs", 42, "\"old\"", "eight", framework: "net8.0");
+        var nine = Patch("Tests.cs", 42, "\"old\"", "nine", framework: "net9.0");
         var entry = new PendingInline([new(eight, ["net8.0"]), new(nine, ["net9.0"])]);
 
         var listed = ViewerListing.Items([entry], withPatches: false).Single();

diff --git a/src/DiffEngine/Inline/InlinePatch.cs b/src/DiffEngine/Inline/InlinePatch.cs
@@ -49,10 +49,18 @@ public InlinePatch(
     public InlinePatchMode Mode { get; set; }
 
     /// <summary>
-    /// Display name of the test that produced this patch. Optional; supplied by the caller
-    /// (Verify). Null when the caller did not provide one.
+    /// Display name of the test that produced this patch, supplied by the caller (Verify). The
+    /// viewer labels and groups queue entries by it, falling back to the call site without one.
+    /// <para>
+    /// Required, though still nullable: a patch that never reaches a queue — an
+    /// <see cref="InlinePatchMode.Remove"/>, or an apply straight through
+    /// <see cref="InlineApplier"/> — has no reviewable identity and says so with an explicit null.
+    /// Omission and decision were previously indistinguishable, and a producer that simply never
+    /// set it went unnoticed for as long as it did because the viewer's fallback reads as an
+    /// unnamed test rather than as a missing field.
+    /// </para>
     /// </summary>
-    public string? TestName { get; set; }
+    public required string? TestName { get; set; }
 
     /// <summary>
     /// Short target framework of the test process that produced this patch ("net9.0", "net48").

diff --git a/src/DiffEngineTray.Tests/DebugReportTests.cs b/src/DiffEngineTray.Tests/DebugReportTests.cs
@@ -78,7 +78,10 @@ public async Task Owned()
 
         var source = Path.Combine(directory, "SampleTests.cs");
         await File.WriteAllTextAsync(source, "");
-        var patch = new InlinePatch(source, 42, "\"old\"", "line one\nline two");
+        var patch = new InlinePatch(source, 42, "\"old\"", "line one\nline two")
+        {
+            TestName = null
+        };
         // Over the socket, as the test process that failed the assertion sends it
         if (!ViewerClient.TrySend(new(ViewerVerb.Inline, Body: InlinePatchFile.Build(patch)), out _, host.Port))
         {

diff --git a/src/DiffEngineTray.Tests/OwnedInlineHostTest.cs b/src/DiffEngineTray.Tests/OwnedInlineHostTest.cs
@@ -31,10 +31,16 @@ public ViewerResponse Send(ViewerMessage message)
             return response;
         }
 
-        public ViewerResponse Queue(string source = @"c:\repo\SampleTests.cs", int line = 42, string content = "new", string? framework = null) =>
+        public ViewerResponse Queue(
+            string source = @"c:\repo\SampleTests.cs",
+            int line = 42,
+            string content = "new",
+            string? framework = null,
+            string? testName = null) =>
             Send(new(ViewerVerb.Inline, Body: InlinePatchFile.Build(new(source, line, "\"old\"", content)
             {
-                Framework = framework
+                Framework = framework,
+                TestName = testName
             })));
 
         public void Dispose() =>

diff --git a/src/DiffEngineTray.Tests/TrayViewerSyncTest.cs b/src/DiffEngineTray.Tests/TrayViewerSyncTest.cs
@@ -648,7 +648,8 @@ static string Payload(string source, int line, string content, string? framework
         InlinePatchFile.Build(
             new(source, line, "\"old\"", content)
             {
-                Framework = framework
+                Framework = framework,
+                TestName = null
             });
 
     /// <summary>