diff --git a/Buildenator/CodeAnalysis/ITypedSymbol.cs b/Buildenator/CodeAnalysis/ITypedSymbol.cs
index a693a13..acce241 100644
--- a/Buildenator/CodeAnalysis/ITypedSymbol.cs
+++ b/Buildenator/CodeAnalysis/ITypedSymbol.cs
@@ -7,6 +7,12 @@ internal interface ITypedSymbol
string SymbolName { get; }
string SymbolPascalName { get; }
string TypeFullName { get; }
+ ///
+ /// Gets the type name suitable for use as a NullBox generic parameter.
+ /// For nullable reference types, returns the non-nullable version.
+ /// For nullable value types, returns the type as-is since Nullable<T> is the actual type.
+ ///
+ string NonNullableTypeFullName { get; }
string TypeName { get; }
string UnderScoreName { get; }
diff --git a/Buildenator/CodeAnalysis/TypedSymbol.cs b/Buildenator/CodeAnalysis/TypedSymbol.cs
index 68d6e67..bb620de 100644
--- a/Buildenator/CodeAnalysis/TypedSymbol.cs
+++ b/Buildenator/CodeAnalysis/TypedSymbol.cs
@@ -56,6 +56,35 @@ private TypedSymbol(
private string? _typeFullName;
public string TypeFullName => _typeFullName ??= Type.ToDisplayString();
+ private string? _nonNullableTypeFullName;
+ ///
+ /// Gets the type name suitable for use as a NullBox generic parameter.
+ /// For nullable reference types (e.g., "string?", "Dictionary<K,V>?"), returns the non-nullable version.
+ /// For nullable value types (e.g., "int?"), returns the type as-is since Nullable<T> is the actual type.
+ ///
+ public string NonNullableTypeFullName => _nonNullableTypeFullName ??= GetNonNullableTypeFullName();
+
+ private string GetNonNullableTypeFullName()
+ {
+ // For nullable value types (e.g., int?, DateTime?), keep the nullable form
+ // because Nullable is the actual type, not just an annotation
+ if (Type.TypeKind == TypeKind.Struct && Type is INamedTypeSymbol namedType &&
+ namedType.OriginalDefinition.SpecialType == SpecialType.System_Nullable_T)
+ {
+ return TypeFullName;
+ }
+
+ // For nullable reference types, strip the nullable annotation
+ // This handles cases like string?, Dictionary?, etc.
+ if (Type.NullableAnnotation == NullableAnnotation.Annotated)
+ {
+ return Type.WithNullableAnnotation(NullableAnnotation.NotAnnotated).ToDisplayString();
+ }
+
+ // For non-nullable types, return as-is
+ return TypeFullName;
+ }
+
public string TypeName => Type.Name;
public string SymbolPascalName => Symbol.PascalCaseName();
diff --git a/Buildenator/Generators/ConstructorsGenerator.cs b/Buildenator/Generators/ConstructorsGenerator.cs
index 13bc7cf..19c7dc5 100644
--- a/Buildenator/Generators/ConstructorsGenerator.cs
+++ b/Buildenator/Generators/ConstructorsGenerator.cs
@@ -84,11 +84,12 @@ private static string GenerateEmptyCollectionInitialization(ITypedSymbol typedSy
{
var fieldName = typedSymbol.UnderScoreName;
var typeFullName = typedSymbol.TypeFullName;
+ var nonNullableTypeFullName = typedSymbol.NonNullableTypeFullName;
// For concrete dictionary types, create new instance
if (collectionMetadata is ConcreteDictionaryMetadata)
{
- return $"{fieldName} = new {DefaultConstants.NullBox}<{typeFullName}>(new {typeFullName}());";
+ return $"{fieldName} = new {DefaultConstants.NullBox}<{typeFullName}>(new {nonNullableTypeFullName}());";
}
// For interface dictionary types, create a Dictionary
@@ -103,7 +104,7 @@ private static string GenerateEmptyCollectionInitialization(ITypedSymbol typedSy
// Standard .NET collections (List, HashSet, Collection, etc.) all support this.
if (collectionMetadata is ConcreteCollectionMetadata)
{
- return $"{fieldName} = new {DefaultConstants.NullBox}<{typeFullName}>(new {typeFullName}());";
+ return $"{fieldName} = new {DefaultConstants.NullBox}<{typeFullName}>(new {nonNullableTypeFullName}());";
}
// For interface collection types, create a List
diff --git a/Buildenator/Generators/PropertiesStringGenerator.cs b/Buildenator/Generators/PropertiesStringGenerator.cs
index b330061..ea5bcba 100644
--- a/Buildenator/Generators/PropertiesStringGenerator.cs
+++ b/Buildenator/Generators/PropertiesStringGenerator.cs
@@ -189,9 +189,12 @@ private string GenerateMethodDefinitionHeader(ITypedSymbol typedSymbol)
=> $"public {_builder.FullName} {CreateMethodName(typedSymbol)}({typedSymbol.GenerateMethodParameterDefinition()})";
private static string GenerateValueAssignment(ITypedSymbol typedSymbol)
- => typedSymbol.IsMockable()
- ? $"{DefaultConstants.SetupActionLiteral}({typedSymbol.UnderScoreName})"
- : $"{typedSymbol.UnderScoreName} = new {DefaultConstants.NullBox}<{typedSymbol.TypeFullName}>({DefaultConstants.ValueLiteral})";
+ {
+ if (typedSymbol.IsMockable())
+ return $"{DefaultConstants.SetupActionLiteral}({typedSymbol.UnderScoreName})";
+
+ return $"{typedSymbol.UnderScoreName} = new {DefaultConstants.NullBox}<{typedSymbol.TypeFullName}>({DefaultConstants.ValueLiteral})";
+ }
private string CreateMethodName(ITypedSymbol property) => $"{_builder.BuildingMethodsPrefix}{property.SymbolPascalName}";
@@ -219,7 +222,7 @@ private string GenerateAddToMethodDefinition(ITypedSymbol typedSymbol)
}}
else
{{
- dictionary = new {typedSymbol.TypeFullName}();
+ dictionary = new {typedSymbol.NonNullableTypeFullName}();
}}
foreach (var item in items)
@@ -264,7 +267,7 @@ private string GenerateAddToMethodDefinition(ITypedSymbol typedSymbol)
}}
else
{{
- collection = new {typedSymbol.TypeFullName}();
+ collection = new {typedSymbol.NonNullableTypeFullName}();
}}
foreach (var item in items)
@@ -315,13 +318,12 @@ private string GenerateChildBuilderMethodDefinition(ITypedSymbol typedSymbol)
var methodName = CreateMethodName(typedSymbol);
var fieldName = typedSymbol.UnderScoreName;
- var entityTypeName = typedSymbol.TypeFullName;
return $@"public {_builder.FullName} {methodName}(System.Func<{childBuilderName}, {childBuilderName}> configure{typedSymbol.SymbolPascalName})
{{
var childBuilder = new {childBuilderName}();
childBuilder = configure{typedSymbol.SymbolPascalName}(childBuilder);
- {fieldName} = new {DefaultConstants.NullBox}<{entityTypeName}>(childBuilder.Build());
+ {fieldName} = new {DefaultConstants.NullBox}<{typedSymbol.TypeFullName}>(childBuilder.Build());
return this;
}}";
}
@@ -347,7 +349,7 @@ private string GenerateChildBuilderAddToMethodDefinition(ITypedSymbol typedSymbo
}}
else
{{
- collection = new {typedSymbol.TypeFullName}();
+ collection = new {typedSymbol.NonNullableTypeFullName}();
}}
foreach (var configure in configures)
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4876234..f216d04 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+## Unreleased
+
+### Fixed
+- **Nullable dictionary support**: Fixed compilation error when models have nullable dictionary properties (e.g., `Dictionary?`, `IDictionary?`, `IReadOnlyDictionary?`). The generator now correctly handles nullable reference types in `NullBox` type parameters by stripping the nullable annotation.
+
## 8.7.0.0 - 2025-11-27
### Added
diff --git a/Tests/Buildenator.IntegrationTests.SharedEntitiesNullable/EntityWithNullableDictionary.cs b/Tests/Buildenator.IntegrationTests.SharedEntitiesNullable/EntityWithNullableDictionary.cs
new file mode 100644
index 0000000..68da425
--- /dev/null
+++ b/Tests/Buildenator.IntegrationTests.SharedEntitiesNullable/EntityWithNullableDictionary.cs
@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+
+namespace Buildenator.IntegrationTests.SharedEntitiesNullable
+{
+ ///
+ /// Entity used to test nullable dictionary handling in generated builders.
+ /// Tests various nullable dictionary types.
+ ///
+ public class EntityWithNullableDictionary
+ {
+ ///
+ /// Nullable Dictionary property
+ ///
+ public Dictionary? Metadata { get; set; }
+
+ ///
+ /// Nullable IDictionary property
+ ///
+ public IDictionary? Items { get; set; }
+
+ ///
+ /// Nullable IReadOnlyDictionary property
+ ///
+ public IReadOnlyDictionary? Settings { get; set; }
+
+ ///
+ /// Another nullable Dictionary property
+ ///
+ public Dictionary? Scores { get; set; }
+
+ ///
+ /// Simple non-dictionary property for comparison
+ ///
+ public string? Name { get; set; }
+
+ ///
+ /// Nullable value type property to test int? handling
+ ///
+ public int? Count { get; set; }
+ }
+}
diff --git a/Tests/Buildenator.IntegrationTests.SourceNullable/Builders/EntityWithNullableDictionaryBuilder.cs b/Tests/Buildenator.IntegrationTests.SourceNullable/Builders/EntityWithNullableDictionaryBuilder.cs
new file mode 100644
index 0000000..e4f4b6f
--- /dev/null
+++ b/Tests/Buildenator.IntegrationTests.SourceNullable/Builders/EntityWithNullableDictionaryBuilder.cs
@@ -0,0 +1,10 @@
+using Buildenator.Abstraction;
+using Buildenator.IntegrationTests.SharedEntitiesNullable;
+
+namespace Buildenator.IntegrationTests.SourceNullable.Builders
+{
+ [MakeBuilder(typeof(EntityWithNullableDictionary))]
+ public partial class EntityWithNullableDictionaryBuilder
+ {
+ }
+}
diff --git a/Tests/Buildenator.IntegrationTests/BuildersGeneratorNullableTests.cs b/Tests/Buildenator.IntegrationTests/BuildersGeneratorNullableTests.cs
index f8e44cc..738eb6d 100644
--- a/Tests/Buildenator.IntegrationTests/BuildersGeneratorNullableTests.cs
+++ b/Tests/Buildenator.IntegrationTests/BuildersGeneratorNullableTests.cs
@@ -258,5 +258,110 @@ public void BuildersGenerator_ReadOnlyProperty_ShouldCreateMethodForSettingItsVa
builder.WithPrivateField(privateField);
builder.Build().PrivateField.Should().BeEquivalentTo(privateField);
}
+
+ [Theory]
+ [AutoData]
+ public void BuildersGenerator_NullableDictionary_WithMethodShouldSetValue(string key, string value)
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+ var metadata = new Dictionary { { key, value } };
+
+ // Act
+ var result = builder
+ .WithMetadata(metadata)
+ .Build();
+
+ // Assert
+ _ = result.Metadata.Should().NotBeNull();
+ _ = result.Metadata.Should().HaveCount(1);
+ _ = result.Metadata![key].Should().Be(value);
+ }
+
+ [Theory]
+ [AutoData]
+ public void BuildersGenerator_NullableIDictionary_WithMethodShouldSetValue(int key, string value)
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+ var items = new Dictionary { { key, value } };
+
+ // Act
+ var result = builder
+ .WithItems(items)
+ .Build();
+
+ // Assert
+ _ = result.Items.Should().NotBeNull();
+ _ = result.Items.Should().HaveCount(1);
+ _ = result.Items![key].Should().Be(value);
+ }
+
+ [Fact]
+ public void BuildersGenerator_NullableDictionary_WithNullValueShouldWork()
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+
+ // Act
+ var result = builder
+ .WithMetadata(null)
+ .Build();
+
+ // Assert
+ _ = result.Metadata.Should().BeNull();
+ }
+
+ [Theory]
+ [AutoData]
+ public void BuildersGenerator_NullableDictionary_AddToMethodShouldAddItems(string key1, string value1, string key2, string value2)
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+
+ // Act
+ var result = builder
+ .AddToMetadata(
+ new KeyValuePair(key1, value1),
+ new KeyValuePair(key2, value2))
+ .Build();
+
+ // Assert
+ _ = result.Metadata.Should().NotBeNull();
+ _ = result.Metadata.Should().HaveCount(2);
+ _ = result.Metadata![key1].Should().Be(value1);
+ _ = result.Metadata[key2].Should().Be(value2);
+ }
+
+ [Theory]
+ [AutoData]
+ public void BuildersGenerator_NullableValueType_WithMethodShouldSetValue(int value)
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+
+ // Act
+ var result = builder
+ .WithCount(value)
+ .Build();
+
+ // Assert
+ _ = result.Count.Should().Be(value);
+ }
+
+ [Fact]
+ public void BuildersGenerator_NullableValueType_WithNullValueShouldWork()
+ {
+ // Arrange
+ var builder = EntityWithNullableDictionaryBuilder.EntityWithNullableDictionary;
+
+ // Act
+ var result = builder
+ .WithCount(null)
+ .Build();
+
+ // Assert
+ _ = result.Count.Should().BeNull();
+ }
}
}