fix: plan a oneof case that names a proto-bound record as that record

GUIDE.md

@@ -1509,6 +1509,9 @@ record response {
 }
 ```
 
+A case may name a proto-bound record. Its payload is that record's model, which
+converts with the record's own converter.
+
 Python represents a protobuf oneof-backed variant as a union of slotted case
 dataclasses. Each case contains its payload in a `value` field. For example, the
 variant above generates `OutcomeSuccess(value)` and `OutcomeFailure(value)`. The

advanced/samples/README.md

@@ -163,13 +163,18 @@ crate omits from the API of a resource method's request is left out of the
 model. nexgen ignores the directives that it doesn't know yet, such as
 `@nexus.varargs` and `@nexus.close`.
 
-Python and TypeScript don't generate the service. They panic on the read item, a
-`oneof` of proto-bound records, and Python can't import the protos. .NET types
-each case of the read item as its proto class.
+Some of the output doesn't type-check. Python imports the Stream protos from
+`temporalio`, which doesn't have them, so basedpyright skips the service.
+TypeScript passes a `number` where a resource method's proto request wants a
+`Long`. So `tsc` skips the service, but the test still checks its models.
 
 - WIT: [`inputs/stream-service.wit`](inputs/stream-service.wit)
 - .NET: [`dotnet/wit/stream-service/`](dotnet/wit/stream-service/),
   [`dotnet/tests/StreamServiceChecks.cs`](dotnet/tests/StreamServiceChecks.cs)
+- Python: [`python/wit/stream_service/`](python/wit/stream_service/)
+- TypeScript:
+  [`typescript/wit/stream-service/`](typescript/wit/stream-service/),
+  [`typescript/tests/stream-service.test.ts`](typescript/tests/stream-service.test.ts)
 
 ## Supporting files
 

advanced/samples/dotnet/tests/StreamServiceChecks.cs

@@ -1,8 +1,12 @@
 extern alias Streams;
 
+using System.Linq;
 using Temporalio.Converters;
 using Xunit;
+using static Nexgen.DotNetExamples.Tests.TransferTypeTestSupport;
 using StreamServiceExample = Streams::Temporalio.Workflows;
+using WireReadRecordsResponse = Streams::Temporalio.Api.StreamService.V1.ReadRecordsResponse;
+using WireStreamRecord = Streams::Temporalio.Api.Stream.V1.StreamRecord;
 
 namespace Nexgen.DotNetExamples.Tests
 {
@@ -18,5 +22,54 @@ public void StreamWithItsOwnFieldNameRoundTrips()
 
             Assert.Equal("stream-1", decoded.StreamValue.Id);
         }
+
+        // A data item's body goes through the payload converter of the sample assembly, which a
+        // test can't set. The TypeScript test covers data items.
+        [Fact]
+        public void ReadItemsRoundTripAsTheirRecords()
+        {
+            var model = new StreamServiceExample.ReadRecordsResponse(new[]
+            {
+                new StreamServiceExample.StreamRecord
+                {
+                    Item = new StreamServiceExample.StreamItem.Superseded(
+                        new StreamServiceExample.Supersession("workflow-1", new long[] { 7 })),
+                    Offset = 2,
+                },
+                new StreamServiceExample.StreamRecord
+                {
+                    Item = new StreamServiceExample.StreamItem.Close(
+                        new StreamServiceExample.StreamClose
+                        {
+                            Status = StreamServiceExample.StreamCloseStatus
+                                .StreamCloseStatusCompleted,
+                        }),
+                    Offset = 3,
+                },
+            });
+
+            var wire = Assert.IsType<WireReadRecordsResponse>(
+                CreateSdkConverter(typeof(StreamServiceExample.ReadRecordsResponse))
+                    .ToTransferType(model));
+            Assert.Equal(
+                new[]
+                {
+                    WireStreamRecord.ItemOneofCase.Superseded,
+                    WireStreamRecord.ItemOneofCase.Close,
+                },
+                wire.Records.Select(record => record.ItemCase));
+
+            var decoded = FromPayload<StreamServiceExample.ReadRecordsResponse>(ToPayload(model));
+            var superseded = Assert.IsType<StreamServiceExample.StreamItem.Superseded>(
+                decoded.Records[0].Item);
+            Assert.Equal("workflow-1", superseded.Value.ProducerId);
+            Assert.Equal(new long[] { 7 }, superseded.Value.FailedTasks);
+            var close = Assert.IsType<StreamServiceExample.StreamItem.Close>(
+                decoded.Records[1].Item);
+            Assert.Equal(
+                StreamServiceExample.StreamCloseStatus.StreamCloseStatusCompleted,
+                close.Value.Status);
+            Assert.Equal(3, decoded.Records[1].Offset);
+        }
     }
 }