fix: use correct argument types in user defined enumerable mappings w…

…ith an array source parameter (#1125)

Do not generalize enumerable and dictionary source parameter types if there it is a direct user mapping (with a user symbol)

src/Riok.Mapperly/Descriptors/MappingBuilderContext.cs

@@ -62,6 +62,8 @@ bool clearDerivedTypes
 
     protected IMethodSymbol? UserSymbol { get; }
 
+    public bool HasUserSymbol => UserSymbol != null;
+
     /// <summary>
     /// Whether the current mapping code is generated for a <see cref="System.Linq.Expressions.Expression"/>.
     /// </summary>

src/Riok.Mapperly/Descriptors/MappingBuilders/DictionaryMappingBuilder.cs

@@ -267,13 +267,20 @@ private static CollectionInfo BuildCollectionTypeForIDictionary(
         ITypeSymbol value
     )
     {
+        // the types cannot be changed for mappings with a user symbol
+        // as the types are defined by the user
+        if (ctx.HasUserSymbol)
+            return info;
+
         var dictionaryType = info.ImplementedTypes.HasFlag(CollectionType.IReadOnlyDictionary)
             ? BuildDictionaryType(ctx, CollectionType.IReadOnlyDictionary, key, value)
             : info.ImplementedTypes.HasFlag(CollectionType.IDictionary)
                 ? BuildDictionaryType(ctx, CollectionType.IDictionary, key, value)
-                : info.Type;
+                : null;
 
-        return CollectionInfoBuilder.BuildCollectionInfo(ctx.Types, ctx.SymbolAccessor, dictionaryType, info.EnumeratedType);
+        return dictionaryType == null
+            ? info
+            : CollectionInfoBuilder.BuildCollectionInfo(ctx.Types, ctx.SymbolAccessor, dictionaryType, info.EnumeratedType);
     }
 
     private static INamedTypeSymbol BuildDictionaryType(

src/Riok.Mapperly/Descriptors/MappingBuilders/EnumerableMappingBuilder.cs

@@ -413,12 +413,20 @@ or CollectionType.ICollection
 
     private static CollectionInfo BuildCollectionTypeForICollection(MappingBuilderContext ctx, CollectionInfo info)
     {
+        // the types cannot be changed for mappings with a user symbol
+        // as the types are defined by the user
+        if (ctx.HasUserSymbol)
+            return info;
+
         var collectionType = info.ImplementedTypes.HasFlag(CollectionType.IReadOnlyCollection)
             ? BuildCollectionType(ctx, CollectionType.IReadOnlyCollection, info.EnumeratedType)
             : info.ImplementedTypes.HasFlag(CollectionType.ICollection)
                 ? BuildCollectionType(ctx, CollectionType.ICollection, info.EnumeratedType)
-                : info.Type;
-        return CollectionInfoBuilder.BuildCollectionInfo(ctx.Types, ctx.SymbolAccessor, collectionType, info.EnumeratedType);
+                : null;
+
+        return collectionType == null
+            ? info
+            : CollectionInfoBuilder.BuildCollectionInfo(ctx.Types, ctx.SymbolAccessor, collectionType, info.EnumeratedType);
     }
 
     private static INamedTypeSymbol BuildCollectionType(MappingBuilderContext ctx, CollectionType type, ITypeSymbol enumeratedType)

test/Riok.Mapperly.Tests/Mapping/EnumerableTest.cs

@@ -570,6 +570,14 @@ public Task ArrayToCollectionShouldUpgradeNullability()
         return TestHelper.VerifyGenerator(source, TestHelperOptions.DisabledNullable);
     }
 
+    [Fact]
+    public Task ArrayToList()
+    {
+        var source = TestSourceBuilder.Mapping("int[]", "List<string>");
+
+        return TestHelper.VerifyGenerator(source);
+    }
+
     [Fact]
     public Task ArrayToListShouldUpgradeNullability()
     {

test/Riok.Mapperly.Tests/_snapshots/EnumerableTest.ArrayToList#Mapper.g.verified.cs

@@ -0,0 +1,16 @@
+//HintName: Mapper.g.cs
+// <auto-generated />
+#nullable enable
+public partial class Mapper
+{
+    [global::System.CodeDom.Compiler.GeneratedCode("Riok.Mapperly", "0.0.1.0")]
+    private partial global::System.Collections.Generic.List<string> Map(int[] source)
+    {
+        var target = new global::System.Collections.Generic.List<string>(source.Length);
+        foreach (var item in source)
+        {
+            target.Add(item.ToString());
+        }
+        return target;
+    }
+}