Rekhoff/csharp default field values

crates/bindings-csharp/Codegen.Tests/fixtures/diag/Lib.cs

@@ -1,3 +1,4 @@
+using System.ComponentModel;
 using SpacetimeDB;
 
 public enum LocalEnum { }
@@ -361,6 +362,80 @@ public static partial class InAnotherNamespace
     public partial struct TestDuplicateTableName { }
 }
 
+[SpacetimeDB.Table]
+public partial struct TestDefaultFieldValues
+{
+    [Unique]
+    public int? UniqueField;
+
+    [Default("A default string set by attribute")]
+    public string DefaultString = "";
+
+    [Default(true)]
+    public bool DefaultBool = false;
+
+    [Default((sbyte)2)]
+    public sbyte DefaultI8 = 1;
+
+    [Default((byte)2)]
+    public byte DefaultU8 = 1;
+
+    [Default((short)2)]
+    public short DefaultI16 = 1;
+
+    [Default((ushort)2)]
+    public ushort DefaultU16 = 1;
+
+    [Default(2)]
+    public int DefaultI32 = 1;
+
+    [Default(2U)]
+    public uint DefaultU32 = 1U;
+
+    [Default(2L)]
+    public long DefaultI64 = 1L;
+
+    [Default(2UL)]
+    public ulong DefaultU64 = 1UL;
+
+    [Default(0x02)]
+    public int DefaultHex = 1;
+
+    [Default(0b00000010)]
+    public int DefaultBin = 1;
+
+    [Default(2.0f)]
+    public float DefaultF32 = 1.0f;
+
+    [Default(2.0)]
+    public double DefaultF64 = 1.0;
+
+    [Default(MyEnum.SetByAttribute)]
+    public MyEnum DefaultEnum = MyEnum.SetByInitalization;
+
+    [Default(null!)]
+    public MyStruct? DefaultNull = new MyStruct(1);
+}
+
+[SpacetimeDB.Type]
+public enum MyEnum
+{
+    Default,
+    SetByInitalization,
+    SetByAttribute,
+}
+
+[SpacetimeDB.Type]
+public partial struct MyStruct
+{
+    public int x;
+
+    public MyStruct(int x)
+    {
+        this.x = x;
+    }
+}
+
 [SpacetimeDB.Table]
 [SpacetimeDB.Index.BTree(Name = "TestIndexWithoutColumns")]
 [SpacetimeDB.Index.BTree(Name = "TestIndexWithEmptyColumns", Columns = [])]

crates/bindings-csharp/Codegen.Tests/fixtures/diag/snapshots/ExtraCompilationErrors.verified.txt

@@ -92,10 +92,33 @@ var ___hashUnsupportedEnum = UnsupportedEnum.GetHashCode();
     }
   },
   {/*
+[SpacetimeDB.Table]
+public partial struct TestDefaultFieldValues
+                      ^^^^^^^^^^^^^^^^^^^^^^
+{
+*/
+    Message: A 'struct' with field initializers must include an explicitly declared constructor.,
+    Severity: Error,
+    Descriptor: {
+      Id: CS8983,
+      Title: ,
+      HelpLink: https://msdn.microsoft.com/query/roslyn.query?appId=roslyn&k=k(CS8983),
+      MessageFormat: A 'struct' with field initializers must include an explicitly declared constructor.,
+      Category: Compiler,
+      DefaultSeverity: Error,
+      IsEnabledByDefault: true,
+      CustomTags: [
+        Compiler,
+        Telemetry,
+        NotConfigurable
+      ]
+    }
+  },
+  {/*
 SpacetimeDB.Internal.Module.RegisterClientVisibilityFilter(global::Module.MY_SECOND_FILTER);
 SpacetimeDB.Internal.Module.RegisterClientVisibilityFilter(global::Module.MY_THIRD_FILTER);
                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-    }
+        {
 */
     Message: Argument 1: cannot convert from 'string' to 'SpacetimeDB.Filter',
     Severity: Error,