fix(csharp): payload-generator resolves bare @payloadRef in a named package

CHANGELOG.md

@@ -7,6 +7,16 @@ this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Fixed
+
+- **C#** — `PayloadGenerator`/`PayloadCodegen.EmitRecord` failed to emit a payload record at
+  all (silently produced a header-only file) for any `template.output` in a **named package**
+  whose `@payloadRef` was authored bare. `MetaData.Attr()` resolves a bare ref to its
+  fully-qualified form per ADR-0042, but `PayloadCodegen.FindObject`'s bare short-name match
+  never accounted for that — the top-level `voName` needed the same `CSharpNaming.StripPkg`
+  treatment `FieldType` already applies to nested `@objectRef` fields. Adopters outside the
+  default/root package hit this on every `template.output`.
+
 ## [0.17.0] — 2026-07-18
 
 Coordinated additive **minor** across all four registries: **npm `0.17.0`** · **PyPI `0.17.0`** · **NuGet `0.17.0`** · **Maven Central `7.9.0`** (Java/Kotlin). Bundles the accumulated projection/view + read-model + prompt work below, plus a full documentation + agent-context skills refresh (the seven `meta init` skills were accuracy-passed and Fable-reviewed, closing a class of stale-vocabulary and calibration defects; the runtime-ui skill gained its missing Python + C# language references). No breaking changes.

server/csharp/MetaObjects.Codegen.Tests/PayloadGeneratorTests.cs

@@ -0,0 +1,102 @@
+using MetaObjects.Codegen;
+using MetaObjects.Codegen.Generators;
+using MetaObjects.Loader;
+using MetaObjects.Meta;
+using Xunit;
+
+namespace MetaObjects.Codegen.Tests;
+
+/// <summary>
+/// PayloadGenerator emission tests. Mirrors OutputParserGeneratorTests' shape (file-per-
+/// template.output, GenContext wiring) plus the regression this generator specifically needed:
+/// a template.output declared in a NAMED package with a BARE @payloadRef. ADR-0042 resolves
+/// that bare attr to its fully-qualified form (MetaData.Attr() returns "pkg::Name", not the
+/// literal string the author typed) — PayloadCodegen.EmitRecord's FindObject only matched a
+/// bare short name, so the top-level payload record (and its file) silently emitted empty.
+/// Nested @objectRef fields never hit this because FieldType already stripped them; only the
+/// generator's own top-level payloadRef was unstripped.
+/// </summary>
+public sealed class PayloadGeneratorTests
+{
+    private static MetaRoot Load(string model)
+    {
+        var r = new MetaDataLoader().Load([new InMemoryStringSource(model, id: "payload-gen.json")]);
+        Assert.Empty(r.Errors);
+        return r.Root;
+    }
+
+    private static GenContext Ctx(MetaRoot root) => new()
+    {
+        Entities = root.Objects(),
+        Root = root,
+        Config = new GenConfig { OutDir = "/tmp", Namespace = "Acme.Generated" },
+    };
+
+    [Fact]
+    public void Emits_no_files_when_no_template_output_nodes()
+    {
+        const string m = """
+        { "metadata.root": { "package": "acme::ai", "children": [
+          { "object.value": { "name": "Payload", "children": [ { "field.string": { "name": "x" } } ] } },
+          { "template.prompt": { "name": "promptOnly", "@payloadRef": "Payload", "@textRef": "p/x", "@format": "text" } }
+        ]}}
+        """;
+        var files = new PayloadGenerator().Generate(Ctx(Load(m))).ToList();
+        Assert.Empty(files);
+    }
+
+    // Regression: a template.output in a NAMED package (not the default/root package) with a
+    // BARE @payloadRef. Before the fix, this emitted a file with a header comment and NOTHING
+    // else — no record, because FindObject's bare-name match failed against the FQN attr value.
+    [Fact]
+    public void Emits_full_record_for_bare_payloadRef_in_a_named_package()
+    {
+        const string m = """
+        { "metadata.root": { "package": "acme::intake", "children": [
+          { "object.value": { "name": "NoteEntry", "children": [
+            { "field.string": { "name": "value" } },
+            { "field.string": { "name": "reasoning" } }
+          ]}},
+          { "object.value": { "name": "ClassificationResponse", "children": [
+            { "field.string":  { "name": "documentType" } },
+            { "field.decimal": { "name": "confidence" } },
+            { "field.object":  { "name": "note", "@objectRef": "NoteEntry" } }
+          ]}},
+          { "template.output": { "name": "ClassificationResponseTemplate",
+            "@payloadRef": "ClassificationResponse", "@textRef": "ai/classification-response", "@format": "text" } }
+        ]}}
+        """;
+        var files = new PayloadGenerator().Generate(Ctx(Load(m))).ToList();
+
+        var file = Assert.Single(files);
+        Assert.Equal("ClassificationResponse.payload.cs", file.Path);
+        Assert.Contains("public sealed record ClassificationResponse", file.Content);
+        Assert.Contains("public required string documentType { get; init; }", file.Content);
+        Assert.Contains("public required double confidence { get; init; }", file.Content);
+        Assert.Contains("public required NoteEntry note { get; init; }", file.Content);
+        Assert.Contains("public sealed record NoteEntry", file.Content);
+        Assert.Contains("public required string value { get; init; }", file.Content);
+        // The FQN must not leak into the file name or the record/type names.
+        Assert.DoesNotContain("acme::intake::", file.Content);
+        Assert.DoesNotContain("::", file.Path);
+    }
+
+    [Fact]
+    public void Emits_one_file_per_template_output_with_expected_path_and_class()
+    {
+        const string m = """
+        { "metadata.root": { "package": "acme::ai", "children": [
+          { "object.value": { "name": "AlphaPayload", "children": [ { "field.string": { "name": "name" } } ] } },
+          { "object.value": { "name": "BetaPayload",  "children": [ { "field.int":    { "name": "n" } } ] } },
+          { "template.output": { "name": "Alpha", "@payloadRef": "AlphaPayload", "@textRef": "a/x", "@format": "json" } },
+          { "template.output": { "name": "Beta",  "@payloadRef": "BetaPayload",  "@textRef": "b/x", "@format": "json" } }
+        ]}}
+        """;
+        var files = new PayloadGenerator().Generate(Ctx(Load(m))).OrderBy(f => f.Path).ToList();
+        Assert.Equal(2, files.Count);
+        Assert.Equal("AlphaPayload.payload.cs", files[0].Path);
+        Assert.Equal("BetaPayload.payload.cs",  files[1].Path);
+        Assert.Contains("public sealed record AlphaPayload", files[0].Content);
+        Assert.Contains("public sealed record BetaPayload",  files[1].Content);
+    }
+}

server/csharp/MetaObjects.Codegen/Generators/PayloadGenerator.cs

@@ -95,6 +95,8 @@ protected virtual EmittedFile EmitPayload(string payloadRef, GenContext ctx)
         sb.AppendLine($"namespace {ctx.Config.Namespace};");
         sb.AppendLine();
         sb.Append(records);
-        return new EmittedFile($"{payloadRef}.payload.cs", sb.ToString());
+        // payloadRef may be the FQN form (ADR-0042 attr resolution) — the file name is the
+        // bare record name, matching PayloadCodegen.EmitRecord's own stripping.
+        return new EmittedFile($"{CSharpNaming.StripPkg(payloadRef)}.payload.cs", sb.ToString());
     }
 }

server/csharp/MetaObjects.Codegen/PayloadCodegen.cs

@@ -128,6 +128,14 @@ private static List<string> CollectEnumDecls(MetaData vo)
 
     private static void EmitRecord(MetaData root, string voName, HashSet<string> emitted, List<string> output)
     {
+        // A @payloadRef may reach here fully-qualified — ADR-0042 resolves a bare template
+        // attr to the FQN form, and MetaData.Attr() returns that resolved (possibly
+        // package-qualified) value, not the literal string the author typed. FindObject and
+        // the emitted record's own type name both need the bare short name (a C# record
+        // identifier can't contain "::" and isn't package-scoped); nested @objectRef fields
+        // already arrive here pre-stripped via FieldType's CSharpNaming.StripPkg call, so
+        // stripping here is a no-op for them and the fix for the top-level payloadRef case.
+        voName = CSharpNaming.StripPkg(voName);
         if (!emitted.Add(voName)) return;
         var vo = FindObject(root, voName);
         if (vo is null) return;