From 8b5bfe35bcc6f54f9d20e5f0613fa4e904f292e7 Mon Sep 17 00:00:00 2001
From: Blaise Taylor <btaylor@bPolicySolutions.com>
Date: Sat, 31 May 2025 10:21:22 -0400
Subject: [PATCH] Fixes Issue #242. Exception expanding dictionaries in complex
 types.

---
 .../TypeExtensions.cs                         |  8 ++-
 .../AirVinylModel/VinylRecordModel.cs         | 54 ++++++++++++++++++-
 .../ExpansionTests.cs                         | 16 ++++++
 .../Mappings/AirVinylMappings.cs              |  3 ++
 4 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/AutoMapper.AspNetCore.OData.EFCore/TypeExtensions.cs b/AutoMapper.AspNetCore.OData.EFCore/TypeExtensions.cs
index 6932a42..1a7af70 100644
--- a/AutoMapper.AspNetCore.OData.EFCore/TypeExtensions.cs
+++ b/AutoMapper.AspNetCore.OData.EFCore/TypeExtensions.cs
@@ -117,12 +117,18 @@ public static Type GetUnderlyingElementType(this Type type)
 
             if (genericTypeDefinition == typeof(IGrouping<,>))
                 return genericArguments[1];
-            else if (typeof(IDictionary<,>).IsAssignableFrom(genericTypeDefinition))
+            else if (IsGenericDictionaryType())
                 return typeof(KeyValuePair<,>).MakeGenericType(genericArguments[0], genericArguments[1]);
             else if (genericArguments.Length == 1)
                 return genericArguments[0];
             else
                 throw new ArgumentException(nameof(type));
+
+            bool IsGenericDictionaryType()
+            {
+                return (typeof(IDictionary<,>).IsAssignableFrom(genericTypeDefinition))
+                    || (type.GetInterface(typeof(System.Collections.IDictionary).FullName ?? "") != null && genericArguments.Length == 2);
+            }
         }
 
         public static Type GetUnderlyingElementType(this Expression expression)
diff --git a/AutoMapper.OData.EFCore.Tests/AirVinylModel/VinylRecordModel.cs b/AutoMapper.OData.EFCore.Tests/AirVinylModel/VinylRecordModel.cs
index 93e0d15..254a829 100644
--- a/AutoMapper.OData.EFCore.Tests/AirVinylModel/VinylRecordModel.cs
+++ b/AutoMapper.OData.EFCore.Tests/AirVinylModel/VinylRecordModel.cs
@@ -49,6 +49,58 @@ public IDictionary<string, VinylLinkModel> Links {
 
                 return _links;
             } 
-        }            
+        }
+
+        private Dictionary<string, VinylLinkModel> _moreLinks;
+        public Dictionary<string, VinylLinkModel> MoreLinks
+        {
+            get
+            {
+                if (_moreLinks is null)
+                {
+                    _moreLinks = new Dictionary<string, VinylLinkModel>()
+                    {
+                        { "buyingLink", new VinylLinkModel { Href = $"http://test/buy/{VinylRecordId}" } },
+                        { "reviewLink", new VinylLinkModel { Href = $"http://test/review/{VinylRecordId}" } }
+                    };
+                }
+
+                return _moreLinks;
+            }
+        }
+
+        private SortedDictionary<string, VinylLinkModel> _extraLinks;
+        public SortedDictionary<string, VinylLinkModel> ExtraLinks
+        {
+            get
+            {
+                if (_extraLinks is null)
+                {
+                    _extraLinks = new SortedDictionary<string, VinylLinkModel>()
+                    {
+                        { "buyingLink", new VinylLinkModel { Href = $"http://test/buy/{VinylRecordId}" } },
+                        { "reviewLink", new VinylLinkModel { Href = $"http://test/review/{VinylRecordId}" } }
+                    };
+                }
+
+                return _extraLinks;
+            }
+        }
+
+        private System.Collections.Concurrent.ConcurrentDictionary<string, VinylLinkModel> _additionalLinks;
+        public System.Collections.Concurrent.ConcurrentDictionary<string, VinylLinkModel> AdditionalLinks
+        {
+            get
+            {
+                if (_additionalLinks is null)
+                {
+                    _additionalLinks = new System.Collections.Concurrent.ConcurrentDictionary<string, VinylLinkModel>();
+                    _additionalLinks.TryAdd("buyingLink", new VinylLinkModel { Href = $"http://test/buy/{VinylRecordId}" });
+                    _additionalLinks.TryAdd("reviewLink", new VinylLinkModel { Href = $"http://test/review/{VinylRecordId}" });
+                }
+
+                return _additionalLinks;
+            }
+        }
     }
 }
diff --git a/AutoMapper.OData.EFCore.Tests/ExpansionTests.cs b/AutoMapper.OData.EFCore.Tests/ExpansionTests.cs
index 01a30b9..7e9f043 100644
--- a/AutoMapper.OData.EFCore.Tests/ExpansionTests.cs
+++ b/AutoMapper.OData.EFCore.Tests/ExpansionTests.cs
@@ -65,6 +65,22 @@ void Test(ICollection<VinylRecordModel> collection)
             }
         }
 
+        [Fact]
+        public async Task ExpandingComplexTypesSupportsAllGenericDictionaries()
+        {
+            string query = "/vinylrecordmodel";
+            Test(await GetAsync<VinylRecordModel, VinylRecord>(query));
+
+            void Test(ICollection<VinylRecordModel> collection)
+            {
+                Assert.True(collection.Count > 0);
+                Assert.Contains(collection, vinyl => vinyl.Links.Count != 0);
+                Assert.Contains(collection, vinyl => vinyl.MoreLinks.Count != 0);
+                Assert.Contains(collection, vinyl => vinyl.ExtraLinks.Count != 0);
+                Assert.Contains(collection, vinyl => vinyl.AdditionalLinks.Count != 0);
+            }
+        }
+
         [Fact]
         public async Task GetRecordStoresExpandsComplexTypesByDefault()
         {
diff --git a/AutoMapper.OData.EFCore.Tests/Mappings/AirVinylMappings.cs b/AutoMapper.OData.EFCore.Tests/Mappings/AirVinylMappings.cs
index 748dc64..f553a0c 100644
--- a/AutoMapper.OData.EFCore.Tests/Mappings/AirVinylMappings.cs
+++ b/AutoMapper.OData.EFCore.Tests/Mappings/AirVinylMappings.cs
@@ -31,6 +31,9 @@ public AirVinylMappings()
                 .ForAllMembers(o => o.ExplicitExpansion());
             CreateMap<VinylRecord, VinylRecordModel>()
                 .ForMember(dest => dest.Links, o => o.Ignore())
+                .ForMember(dest => dest.MoreLinks, o => o.Ignore())
+                .ForMember(dest => dest.ExtraLinks, o => o.Ignore())
+                .ForMember(dest => dest.AdditionalLinks, o => o.Ignore())
                 .ForAllMembers(o => o.ExplicitExpansion());
         }
     }