Introduce IStructuralProperty

Add support for property bag complex types
Throw for shadow properties on complex types

Fixes #31237

Author: AndriySvyryd

src/EFCore.Relational/Query/CollectionResultExpression.cs

@@ -18,7 +18,7 @@ namespace Microsoft.EntityFrameworkCore.Query;
 /// <param name="elementType">The clr type of individual elements in the collection.</param>
 public class CollectionResultExpression(
     Expression queryExpression,
-    IPropertyBase? relationship,
+    IStructuralProperty? relationship,
     Type elementType)
     : Expression, IPrintableExpression
 {
@@ -30,7 +30,7 @@ public class CollectionResultExpression(
     /// <summary>
     ///     The relationship associated with the collection, if any.
     /// </summary>
-    public virtual IPropertyBase? Relationship { get; } = relationship;
+    public virtual IStructuralProperty? Relationship { get; } = relationship;
 
     /// <summary>
     ///     The clr type of elements of the collection.

src/EFCore.Relational/Query/RelationalShapedQueryCompilingExpressionVisitor.ShaperProcessingExpressionVisitor.cs

@@ -759,17 +759,11 @@ protected override Expression VisitExtension(Expression extensionExpression)
                 case CollectionResultExpression
                 {
                     QueryExpression: ProjectionBindingExpression projectionBindingExpression,
-                    Relationship: IPropertyBase relationship,
+                    Relationship: IStructuralProperty relationship,
                 } collectionResult
                     when GetProjectionIndex(projectionBindingExpression) is JsonProjectionInfo jsonProjectionInfo:
                 {
-                    var relatedStructuralType = relationship switch
-                    {
-                        IComplexProperty complexProperty => (ITypeBase)complexProperty.ComplexType,
-                        INavigation navigation => navigation.TargetEntityType,
-
-                        _ => throw new UnreachableException()
-                    };
+                    var relatedStructuralType = relationship.TargetType;
 
                     // Disallow tracking queries to project owned entities (but not complex types)
                     if (relatedStructuralType is IEntityType && _isTracking)

src/EFCore/Infrastructure/ModelValidator.cs

@@ -354,6 +354,14 @@ protected virtual void ValidatePropertyMapping(IConventionComplexProperty comple
                     CoreStrings.ComplexValueTypeShadowProperty(complexProperty.ComplexType.DisplayName(), shadowProperty.Name));
             }
         }
+
+        // Issue #35613: Shadow properties on all complex types are not supported
+        var shadowPropertyOnComplexType = complexProperty.ComplexType.GetDeclaredProperties().FirstOrDefault(p => p.IsShadowProperty());
+        if (shadowPropertyOnComplexType != null)
+        {
+            throw new InvalidOperationException(
+                CoreStrings.ComplexTypeShadowProperty(complexProperty.ComplexType.DisplayName(), shadowPropertyOnComplexType.Name));
+        }
     }
 
     /// <summary>

src/EFCore/Metadata/IComplexProperty.cs

@@ -9,10 +9,17 @@ namespace Microsoft.EntityFrameworkCore.Metadata;
 /// <remarks>
 ///     See <see href="https://aka.ms/efcore-docs-modeling">Modeling entity types and relationships</see> for more information and examples.
 /// </remarks>
-public interface IComplexProperty : IReadOnlyComplexProperty, IPropertyBase
+public interface IComplexProperty : IReadOnlyComplexProperty, IStructuralProperty
 {
     /// <summary>
     ///     Gets the associated complex type.
     /// </summary>
     new IComplexType ComplexType { get; }
+
+    /// <inheritdoc />
+    ITypeBase IStructuralProperty.TargetType
+    {
+        [DebuggerStepThrough]
+        get => ComplexType;
+    }
 }

src/EFCore/Metadata/IConventionComplexProperty.cs

@@ -15,7 +15,7 @@ namespace Microsoft.EntityFrameworkCore.Metadata;
 ///         See <see href="https://aka.ms/efcore-docs-conventions">Model building conventions</see> for more information and examples.
 ///     </para>
 /// </remarks>
-public interface IConventionComplexProperty : IReadOnlyComplexProperty, IConventionPropertyBase
+public interface IConventionComplexProperty : IReadOnlyComplexProperty, IConventionStructuralProperty
 {
     /// <summary>
     ///     Gets the builder that can be used to configure this property.
@@ -44,4 +44,11 @@ public interface IConventionComplexProperty : IReadOnlyComplexProperty, IConvent
     /// </summary>
     /// <returns>The configuration source for <see cref="IReadOnlyProperty.IsNullable" />.</returns>
     ConfigurationSource? GetIsNullableConfigurationSource();
+
+    /// <inheritdoc />
+    IConventionTypeBase IConventionStructuralProperty.TargetType
+    {
+        [DebuggerStepThrough]
+        get => ComplexType;
+    }
 }

src/EFCore/Metadata/IConventionNavigationBase.cs

@@ -17,8 +17,24 @@ namespace Microsoft.EntityFrameworkCore.Metadata;
 ///         See <see href="https://aka.ms/efcore-docs-conventions">Model building conventions</see> for more information and examples.
 ///     </para>
 /// </remarks>
-public interface IConventionNavigationBase : IReadOnlyNavigationBase, IConventionPropertyBase
+public interface IConventionNavigationBase : IReadOnlyNavigationBase, IConventionStructuralProperty
 {
+    /// <summary>
+    ///     Gets the entity type that this navigation property will hold an instance(s) of.
+    /// </summary>
+    new IConventionEntityType TargetEntityType
+    {
+        [DebuggerStepThrough]
+        get => (IConventionEntityType)((IReadOnlyNavigationBase)this).TargetEntityType;
+    }
+
+    /// <inheritdoc />
+    IConventionTypeBase IConventionStructuralProperty.TargetType
+    {
+        [DebuggerStepThrough]
+        get => TargetEntityType;
+    }
+
     /// <summary>
     ///     Sets a value indicating whether this navigation should be eager loaded by default.
     /// </summary>

src/EFCore/Metadata/IConventionStructuralProperty.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Metadata;
+
+/// <summary>
+///     Represents a structural property that refers to a type.
+/// </summary>
+/// <remarks>
+///     <para>
+///         This interface is used during model creation and allows the metadata to be modified.
+///         Once the model is built, <see cref="IReadOnlyStructuralProperty" /> represents a read-only view of the same metadata.
+///     </para>
+///     <para>
+///         See <see href="https://aka.ms/efcore-docs-conventions">Model building conventions</see> for more information and examples.
+///     </para>
+/// </remarks>
+public interface IConventionStructuralProperty : IReadOnlyStructuralProperty, IConventionPropertyBase
+{
+    /// <summary>
+    ///     Gets the type that this structural property refers to.
+    /// </summary>
+    new IConventionTypeBase TargetType { get; }
+}

src/EFCore/Metadata/IMutableComplexProperty.cs

@@ -16,7 +16,7 @@ namespace Microsoft.EntityFrameworkCore.Metadata;
 ///         examples.
 ///     </para>
 /// </remarks>
-public interface IMutableComplexProperty : IReadOnlyComplexProperty, IMutablePropertyBase
+public interface IMutableComplexProperty : IReadOnlyComplexProperty, IMutableStructuralProperty
 {
     /// <summary>
     ///     Gets the associated complex type.
@@ -31,4 +31,11 @@ public interface IMutableComplexProperty : IReadOnlyComplexProperty, IMutablePro
     /// <inheritdoc />
     bool IReadOnlyComplexProperty.IsNullable
         => IsNullable;
+
+    /// <inheritdoc />
+    IMutableTypeBase IMutableStructuralProperty.TargetType
+    {
+        [DebuggerStepThrough]
+        get => ComplexType;
+    }
 }

src/EFCore/Metadata/IMutableNavigationBase.cs

@@ -18,8 +18,24 @@ namespace Microsoft.EntityFrameworkCore.Metadata;
 ///         examples.
 ///     </para>
 /// </remarks>
-public interface IMutableNavigationBase : IReadOnlyNavigationBase, IMutablePropertyBase
+public interface IMutableNavigationBase : IReadOnlyNavigationBase, IMutableStructuralProperty
 {
+    /// <summary>
+    ///     Gets the entity type that this navigation property will hold an instance(s) of.
+    /// </summary>
+    new IMutableEntityType TargetEntityType
+    {
+        [DebuggerStepThrough]
+        get => (IMutableEntityType)((IReadOnlyNavigationBase)this).TargetEntityType;
+    }
+
+    /// <inheritdoc />
+    IMutableTypeBase IMutableStructuralProperty.TargetType
+    {
+        [DebuggerStepThrough]
+        get => TargetEntityType;
+    }
+
     /// <summary>
     ///     Sets a value indicating whether this navigation should be eager loaded by default.
     /// </summary>

src/EFCore/Metadata/IMutableStructuralProperty.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Metadata;
+
+/// <summary>
+///     Represents a structural property that refers to a type.
+/// </summary>
+/// <remarks>
+///     <para>
+///         This interface is used during model creation and allows the metadata to be modified.
+///         Once the model is built, <see cref="IReadOnlyStructuralProperty" /> represents a read-only view of the same metadata.
+///     </para>
+///     <para>
+///         See <see href="https://aka.ms/efcore-docs-modeling">Modeling entity types and relationships</see> for more information and
+///         examples.
+///     </para>
+/// </remarks>
+public interface IMutableStructuralProperty : IReadOnlyStructuralProperty, IMutablePropertyBase
+{
+    /// <summary>
+    ///     Gets the type that this structural property refers to.
+    /// </summary>
+    new IMutableTypeBase TargetType { get; }
+}