feat: use .Net 8 ToDictionary

riok · Sep 15, 2023 · 3ba19c4 · 3ba19c4
1 parent b54b9a5
commit 3ba19c4
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Showing 2 changed files with 32 additions and 40 deletions.
diff --git a/src/Riok.Mapperly/Descriptors/MappingBuilders/DictionaryMappingBuilder.cs b/src/Riok.Mapperly/Descriptors/MappingBuilders/DictionaryMappingBuilder.cs
@@ -13,6 +13,8 @@ public static class DictionaryMappingBuilder
 {
     private const string SetterIndexerPropertyName = "set_Item";
 
+    private const string ToDictionaryName = "ToDictionary";
+    private const string ToDictionaryMethodName = "global::System.Collections.Generic.Enumerable.ToDictionary";
     private const string ToImmutableDictionaryMethodName = "global::System.Collections.Immutable.ImmutableDictionary.ToImmutableDictionary";
     private const string ToImmutableSortedDictionaryMethodName =
         "global::System.Collections.Immutable.ImmutableSortedDictionary.ToImmutableSortedDictionary";
@@ -37,6 +39,32 @@ or CollectionType.IDictionary
                 or CollectionType.IReadOnlyDictionary
         )
         {
+            // use .NET 8  method .ToDictionary() if value and key mapping is synthetic
+            if (keyMapping.IsSynthetic && valueMapping.IsSynthetic && !keyMapping.TargetType.IsNullable())
+            {
+                var enumerableType = ctx.Types.Get(typeof(IEnumerable<>));
+                var dictionaryType = ctx.Types.Get(typeof(Dictionary<,>));
+
+                var toDictionaryMethod = ctx.Types
+                    .Get(typeof(Enumerable))
+                    .GetMembers(ToDictionaryName)
+                    .OfType<IMethodSymbol>()
+                    .FirstOrDefault(
+                        x =>
+                            x is { IsStatic: true, Parameters.Length: 1, IsGenericMethod: true }
+                            && SymbolEqualityComparer.Default.Equals(x.ReturnType.OriginalDefinition, dictionaryType)
+                            && SymbolEqualityComparer.Default.Equals(
+                                ((INamedTypeSymbol)x.Parameters[0].Type).ConstructedFrom,
+                                enumerableType
+                            )
+                    );
+
+                if (toDictionaryMethod != null)
+                {
+                    return new LinqDictionaryMapping(ctx.Source, ctx.Target, ToDictionaryMethodName, keyMapping, valueMapping);
+                }
+            }
+
             var targetDictionarySymbol = ctx.Types.Get(typeof(Dictionary<,>)).Construct(keyMapping.TargetType, valueMapping.TargetType);
             ctx.ObjectFactories.TryFindObjectFactory(ctx.Source, ctx.Target, out var dictionaryObjectFactory);
             return new ForEachSetDictionaryMapping(

diff --git a/test/Riok.Mapperly.Tests/Mapping/DictionaryTest.cs b/test/Riok.Mapperly.Tests/Mapping/DictionaryTest.cs
@@ -24,16 +24,7 @@ public void DictionaryToSameDictionaryDeepCloning()
         TestHelper
             .GenerateMapper(source)
             .Should()
-            .HaveSingleMethodBody(
-                """
-                var target = new global::System.Collections.Generic.Dictionary<string, long>(source.Count);
-                foreach (var item in source)
-                {
-                    target[item.Key] = item.Value;
-                }
-                return target;
-                """
-            );
+            .HaveSingleMethodBody("return global::System.Collections.Generic.Enumerable.ToDictionary(source);");
     }
 
     [Fact]
@@ -126,16 +117,7 @@ public void KeyValueEnumerableToIDictionary()
         TestHelper
             .GenerateMapper(source)
             .Should()
-            .HaveSingleMethodBody(
-                """
-                var target = new global::System.Collections.Generic.Dictionary<string, int>();
-                foreach (var item in source)
-                {
-                    target[item.Key] = item.Value;
-                }
-                return target;
-                """
-            );
+            .HaveSingleMethodBody("return global::System.Collections.Generic.Enumerable.ToDictionary(source);");
     }
 
     [Fact]
@@ -145,16 +127,7 @@ public void CustomDictionaryToIDictionary()
         TestHelper
             .GenerateMapper(source)
             .Should()
-            .HaveSingleMethodBody(
-                """
-                var target = new global::System.Collections.Generic.Dictionary<string, int>(source.Count);
-                foreach (var item in source)
-                {
-                    target[item.Key] = item.Value;
-                }
-                return target;
-                """
-            );
+            .HaveSingleMethodBody("return global::System.Collections.Generic.Enumerable.ToDictionary(source);");
     }
 
     [Fact]
@@ -164,16 +137,7 @@ public void CustomKeyValueListToIDictionary()
         TestHelper
             .GenerateMapper(source)
             .Should()
-            .HaveSingleMethodBody(
-                """
-                var target = new global::System.Collections.Generic.Dictionary<string, int>(source.Count);
-                foreach (var item in source)
-                {
-                    target[item.Key] = item.Value;
-                }
-                return target;
-                """
-            );
+            .HaveSingleMethodBody("return global::System.Collections.Generic.Enumerable.ToDictionary(source);");
     }
 
     [Fact]