Fixing the embarrassing bug w/ mandatory stream markers. Closes GH-3482

src/EventSourcingTests/mandatory_stream_type_behavior.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using EventSourcingTests.Aggregation;
+using JasperFx.Core;
 using Marten;
 using Marten.Events;
 using Marten.Exceptions;
@@ -87,6 +88,30 @@ await Should.ThrowAsync<NonExistentStreamException>(async () =>
         });
     }
 
+    [Fact]
+    public async Task happy_path_usage_with_guid()
+    {
+        StoreOptions(opts => opts.Events.UseMandatoryStreamTypeDeclaration = true);
+
+        theSession.Events.StartStream<MyAggregate>(Guid.NewGuid(), new AEvent());
+
+        await theSession.SaveChangesAsync();
+    }
+
+    [Fact]
+    public async Task happy_path_usage_with_string()
+    {
+        StoreOptions(opts =>
+        {
+            opts.Events.UseMandatoryStreamTypeDeclaration = true;
+            opts.Events.StreamIdentity = StreamIdentity.AsString;
+        });
+
+        theSession.Events.StartStream<MyAggregate>(Guid.NewGuid().ToString(), new AEvent());
+
+        await theSession.SaveChangesAsync();
+    }
+
     public static void configure_mandatory_stream_type()
     {
         #region sample_UseMandatoryStreamTypeDeclaration

src/Marten/Events/EventGraph.Actions.cs

@@ -71,7 +71,6 @@ internal StreamAction Append(DocumentSessionBase session, string stream, params
     internal StreamAction StartStream(DocumentSessionBase session, Guid id, params object[] events)
     {
         EnsureAsGuidStorage(session);
-        if (UseMandatoryStreamTypeDeclaration) throw new StreamTypeMissingException();
 
         if (id == Guid.Empty)
         {
@@ -123,7 +122,6 @@ internal StreamAction StartEmptyStream(DocumentSessionBase session, string key,
     internal StreamAction StartStream(DocumentSessionBase session, string streamKey, params object[] events)
     {
         EnsureAsStringStorage(session);
-        if (UseMandatoryStreamTypeDeclaration) throw new StreamTypeMissingException();
 
         if (streamKey.IsEmpty())
         {

src/Marten/Events/EventStore.StartStream.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Marten.Exceptions;
 using Marten.Schema.Identity;
 
 namespace Marten.Events;
@@ -62,6 +63,7 @@ public StreamAction StartStream(Guid id, IEnumerable<object> events)
 
     public StreamAction StartStream(Guid id, params object[] events)
     {
+        if (_store.Events.UseMandatoryStreamTypeDeclaration) throw new StreamTypeMissingException();
         return _store.Events.StartStream(_session, id, events);
     }
 
@@ -72,6 +74,7 @@ public StreamAction StartStream(string streamKey, IEnumerable<object> events)
 
     public StreamAction StartStream(string streamKey, params object[] events)
     {
+        if (_store.Events.UseMandatoryStreamTypeDeclaration) throw new StreamTypeMissingException();
         return _store.Events.StartStream(_session, streamKey, events);
     }