Fix SNS batch publish missing message attributes and misplaced Request allocation

src/Transports/AWS/Wolverine.AmazonSns.Tests/Internal/OutgoingSnsBatchTests.cs

@@ -0,0 +1,104 @@
+using Amazon.SimpleNotificationService.Model;
+using Microsoft.Extensions.Logging.Abstractions;
+using Shouldly;
+using Wolverine.AmazonSns.Internal;
+
+namespace Wolverine.AmazonSns.Tests.Internal;
+
+public class OutgoingSnsBatchTests
+{
+    private readonly AmazonSnsTopic _topic;
+
+    public OutgoingSnsBatchTests()
+    {
+        _topic = new AmazonSnsTopic("test-topic", new AmazonSnsTransport())
+        {
+            TopicArn = "arn:aws:sns:us-east-1:000000000000:test-topic",
+            Mapper = new StubMapper()
+        };
+    }
+
+    [Fact]
+    public void batch_entries_include_message_attributes_from_mapper()
+    {
+        _topic.Mapper = new StubMapper(("my-attr", "my-value"));
+
+        var envelope = new Envelope { Id = Guid.NewGuid() };
+        var batch = new OutgoingSnsBatch(_topic, NullLogger.Instance, [envelope]);
+
+        var entry = batch.Request.PublishBatchRequestEntries.ShouldHaveSingleItem();
+        entry.MessageAttributes.ShouldNotBeNull();
+        entry.MessageAttributes["my-attr"].StringValue.ShouldBe("my-value");
+    }
+
+    [Fact]
+    public void request_is_constructed_even_when_envelope_fails_mapping()
+    {
+        _topic.Mapper = new ThrowingMapper();
+
+        var envelope = new Envelope { Id = Guid.NewGuid() };
+        var batch = new OutgoingSnsBatch(_topic, NullLogger.Instance, [envelope]);
+
+        batch.Request.ShouldNotBeNull();
+        batch.Request.TopicArn.ShouldBe(_topic.TopicArn);
+        batch.Request.PublishBatchRequestEntries.ShouldBeEmpty();
+    }
+
+    [Fact]
+    public void mapping_failure_does_not_block_other_entries()
+    {
+        _topic.Mapper = new FailOnSecondMapper();
+
+        var envelopes = new[]
+        {
+            new Envelope { Id = Guid.NewGuid() },
+            new Envelope { Id = Guid.NewGuid() },
+            new Envelope { Id = Guid.NewGuid() }
+        };
+
+        var batch = new OutgoingSnsBatch(_topic, NullLogger.Instance, envelopes);
+
+        batch.Request.PublishBatchRequestEntries.Count.ShouldBe(2);
+    }
+
+    private class StubMapper : ISnsEnvelopeMapper
+    {
+        private readonly (string Key, string Value)[] _attributes;
+
+        public StubMapper(params (string Key, string Value)[] attributes) => _attributes = attributes;
+
+        public string BuildMessageBody(Envelope envelope) => "body";
+
+        public IEnumerable<KeyValuePair<string, MessageAttributeValue>> ToAttributes(Envelope envelope)
+        {
+            foreach (var (key, value) in _attributes)
+                yield return new(key, new MessageAttributeValue { StringValue = value, DataType = "String" });
+        }
+
+        public void ReadEnvelopeData(Envelope envelope, string messageBody,
+            IDictionary<string, MessageAttributeValue> attributes) { }
+    }
+
+    private class ThrowingMapper : ISnsEnvelopeMapper
+    {
+        public string BuildMessageBody(Envelope envelope) => throw new Exception("mapping failure");
+        public IEnumerable<KeyValuePair<string, MessageAttributeValue>> ToAttributes(Envelope envelope) => [];
+        public void ReadEnvelopeData(Envelope envelope, string messageBody,
+            IDictionary<string, MessageAttributeValue> attributes) { }
+    }
+
+    private class FailOnSecondMapper : ISnsEnvelopeMapper
+    {
+        private int _callCount;
+
+        public string BuildMessageBody(Envelope envelope)
+        {
+            if (++_callCount == 2) throw new Exception("mapping failure");
+            return "body";
+        }
+
+        public IEnumerable<KeyValuePair<string, MessageAttributeValue>> ToAttributes(Envelope envelope) => [];
+        public void ReadEnvelopeData(Envelope envelope, string messageBody,
+            IDictionary<string, MessageAttributeValue> attributes) { }
+    }
+}

src/Transports/AWS/Wolverine.AmazonSns/Internal/SnsSenderProtocol.cs

@@ -57,7 +57,7 @@
                 var entry = new PublishBatchRequestEntry
                 {
                     Id = envelope.Id.ToString(),
                     Message = topic.Mapper.BuildMessageBody(envelope)
                 };
 
                 if (envelope.GroupId.IsNotEmpty())
@@ -69,6 +69,12 @@
                     entry.MessageDeduplicationId = envelope.DeduplicationId;
                 }
 
+                foreach (var attribute in topic.Mapper.ToAttributes(envelope))
+                {
+                    entry.MessageAttributes ??= new();
+                    entry.MessageAttributes.Add(attribute.Key, attribute.Value);
+                }
+
                 entries.Add(entry);
                 _envelopes.Add(entry.Id, envelope);
             }
@@ -78,13 +84,13 @@
                     envelope);
                 _mappingFailures.Add(envelope);
             }
-
-            Request = new PublishBatchRequest
-            {
-                TopicArn = topic.TopicArn,
-                PublishBatchRequestEntries = entries
-            };
         }
+
+        Request = new PublishBatchRequest
+        {
+            TopicArn = topic.TopicArn,
+            PublishBatchRequestEntries = entries
+        };
     }
 
     public async Task ProcessSuccessAsync(ISenderCallback callback, PublishBatchResponse response,