Adding coverlet threshold to builds.

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
       run: dotnet nuget add source https://www.myget.org/F/automapperdev/api/v3/index.json -n automappermyget
 
     - name: Test
-      run: dotnet test --configuration Release --verbosity normal
+      run: dotnet test --configuration Release --verbosity normal /p:CollectCoverage=true /p:Threshold=94 /p:ThresholdType=line /p:ThresholdStat=Average /p:CoverletOutputFormat=opencover /p:CoverletOutput=./TestResults/ /p:ExcludeByAttribute="GeneratedCodeAttribute"
 
     - name: Pack and push
       env:

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
         fetch-depth: 0
 
     - name: Test
-      run: dotnet test --configuration Release --verbosity normal
+      run: dotnet test --configuration Release --verbosity normal /p:CollectCoverage=true /p:Threshold=94 /p:ThresholdType=line /p:ThresholdStat=Average /p:CoverletOutputFormat=opencover /p:CoverletOutput=./TestResults/ /p:ExcludeByAttribute="GeneratedCodeAttribute"
 
     - name: Pack and push
       env:

README.md

@@ -69,7 +69,7 @@ The methods below map the DTO query expresions to the equivalent data query expr
             return mapper.Map<TDataResult, TModelResult>(mappedQueryFunc(query));
         }
 
-        //This version compiles the queryable expression.
+        //This example compiles the queryable expression.
         internal static IQueryable<TModel> GetQuery1<TModel, TData>(this IQueryable<TData> query,
             IMapper mapper,
             Expression<Func<TModel, bool>> filter = null,
@@ -87,7 +87,7 @@ The methods below map the DTO query expresions to the equivalent data query expr
             Expression<Func<TModel, object>>[] GetExpansions() => expansions?.ToArray() ?? [];
         }
 
-        //This version updates IQueryable<TData>.Expression with the mapped queryable expression parameter.
+        //This example updates IQueryable<TData>.Expression with the mapped queryable expression argument.
         internal static IQueryable<TModel> GetQuery2<TModel, TData>(this IQueryable<TData> query,
             IMapper mapper,
             Expression<Func<TModel, bool>> filter = null,
@@ -128,3 +128,68 @@ The methods below map the DTO query expresions to the equivalent data query expr
         }
     }
 ```
+
+## Known Issues
+Mapping a single type in the source expression to multiple types in the destination expression is not supported e.g.
+```c#
+```
+        [Fact]
+        public void Can_map_if_source_type_targets_multiple_destination_types_in_the_same_expression()
+        {
+            var mapper = ConfigurationHelper.GetMapperConfiguration(cfg =>
+            {
+                cfg.CreateMap<SourceType, TargetType>().ReverseMap();
+                cfg.CreateMap<SourceChildType, TargetChildType>().ReverseMap();
+
+                // Same source type can map to different target types. This seems unsupported currently.
+                cfg.CreateMap<SourceListItemType, TargetListItemType>().ReverseMap();
+                cfg.CreateMap<SourceListItemType, TargetChildListItemType>().ReverseMap();
+
+            }).CreateMapper();
+
+            Expression<Func<SourceType, bool>> sourcesWithListItemsExpr = src => src.Id != 0 && src.ItemList.Any() && src.Child.ItemList.Any(); // Sources with non-empty ItemList
+            Expression<Func<TargetType, bool>> target1sWithListItemsExpr = mapper.MapExpression<Expression<Func<TargetType, bool>>>(sourcesWithListItemsExpr);
+        }
+
+        private class SourceChildType
+        {
+            public int Id { get; set; }
+            public IEnumerable<SourceListItemType> ItemList { get; set; } // Uses same type (SourceListItemType) for its itemlist as SourceType
+        }
+
+        private class SourceType
+        {
+            public int Id { get; set; }
+            public SourceChildType Child { set; get; }
+            public IEnumerable<SourceListItemType> ItemList { get; set; }
+        }
+
+        private class SourceListItemType
+        {
+            public int Id { get; set; }
+        }
+
+        private class TargetChildType
+        {
+            public virtual int Id { get; set; }
+            public virtual ICollection<TargetChildListItemType> ItemList { get; set; } = [];
+        }
+
+        private class TargetChildListItemType
+        {
+            public virtual int Id { get; set; }
+        }
+
+        private class TargetType
+        {
+            public virtual int Id { get; set; }
+
+            public virtual TargetChildType Child { get; set; }
+
+            public virtual ICollection<TargetListItemType> ItemList { get; set; } = [];
+        }
+
+        private class TargetListItemType
+        {
+            public virtual int Id { get; set; }
+        }

src/AutoMapper.Extensions.ExpressionMapping/XpressionMapperVisitor.cs

@@ -183,7 +183,8 @@ protected override Expression VisitLambda<T>(Expression<T> node)
 
         protected override Expression VisitNew(NewExpression node)
         {
-            if (this.TypeMappings.TryGetValue(node.Type, out Type newType))
+            Type newType = this.TypeMappingsManager.ReplaceType(node.Type);
+            if (newType != node.Type && !IsAnonymousType(node.Type))
             {
                 return Expression.New(newType);
             }
@@ -217,7 +218,8 @@ private static bool IsAnonymousType(Type type)
 
         protected override Expression VisitMemberInit(MemberInitExpression node)
         {
-            if (this.TypeMappings.TryGetValue(node.Type, out Type newType))
+            Type newType = this.TypeMappingsManager.ReplaceType(node.Type);
+            if (newType != node.Type && !IsAnonymousType(node.Type))
             {
                 var typeMap = ConfigurationProvider.CheckIfTypeMapExists(sourceType: newType, destinationType: node.Type);
                 //The destination becomes the source because to map a source expression to a destination expression,
@@ -474,7 +476,8 @@ Expression DoVisitConditional(Expression test, Expression ifTrue, Expression ifF
 
         protected override Expression VisitTypeBinary(TypeBinaryExpression node)
         {
-            if (this.TypeMappings.TryGetValue(node.TypeOperand, out Type mappedType))
+            Type mappedType = this.TypeMappingsManager.ReplaceType(node.TypeOperand);
+            if (mappedType != node.TypeOperand)
                 return MapTypeBinary(this.Visit(node.Expression));
 
             return base.VisitTypeBinary(node);
@@ -498,7 +501,8 @@ protected override Expression VisitUnary(UnaryExpression node)
 
             Expression DoVisitUnary(Expression updated)
             {
-                if (this.TypeMappings.TryGetValue(node.Type, out Type mappedType))
+                Type mappedType = this.TypeMappingsManager.ReplaceType(node.Type);
+                if (mappedType != node.Type)
                     return Expression.MakeUnary
                     (
                         node.NodeType,

tests/AutoMapper.Extensions.ExpressionMapping.UnitTests/CanMapIfASourceTypeTargetsMultipleDestinationTypesInTheSameExpression.cs

@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+using Xunit;
+
+namespace AutoMapper.Extensions.ExpressionMapping.UnitTests
+{
+    public class CanMapIfASourceTypeTargetsMultipleDestinationTypesInTheSameExpression
+    {
+#pragma warning disable xUnit1004 // Test methods should not be skipped
+        [Fact(Skip = "This test is currently skipped due to unsupported scenario.")]
+#pragma warning restore xUnit1004 // Test methods should not be skipped
+        public void Can_map_if_source_type_targets_multiple_destination_types_in_the_same_expression()
+        {
+            // Arrange
+            var mapper = ConfigurationHelper.GetMapperConfiguration(cfg =>
+            {
+                cfg.CreateMap<SourceType, TargetType>().ReverseMap();
+                cfg.CreateMap<SourceChildType, TargetChildType>().ReverseMap();
+
+                // Same source type can map to different target types. This seems unsupported currently.
+                cfg.CreateMap<SourceListItemType, TargetListItemType>().ReverseMap();
+                cfg.CreateMap<SourceListItemType, TargetChildListItemType>().ReverseMap();
+
+            }).CreateMapper();
+            Expression<Func<SourceType, bool>> sourcesWithListItemsExpr = src => src.Id != 0 && src.ItemList.Any() && src.Child.ItemList.Any(); // Sources with non-empty ItemList
+
+            // Act
+            Expression<Func<TargetType, bool>> target1sWithListItemsExpr = mapper.MapExpression<Expression<Func<TargetType, bool>>>(sourcesWithListItemsExpr);
+
+            // Assert
+            Assert.NotNull(target1sWithListItemsExpr);
+        }
+
+#pragma warning disable xUnit1004 // Test methods should not be skipped
+        [Fact(Skip = "This test is currently skipped due to unsupported scenario.")]
+#pragma warning restore xUnit1004 // Test methods should not be skipped
+        public void Can_map_if_source_type_targets_multiple_destination_types_in_the_same_expression_including_nested_parameters()
+        {
+            // Arrange
+            var mapper = ConfigurationHelper.GetMapperConfiguration(cfg =>
+            {
+                cfg.CreateMap<SourceType, TargetType>().ReverseMap();
+                cfg.CreateMap<SourceChildType, TargetChildType>().ReverseMap();
+
+                // Same source type can map to different target types. This seems unsupported currently.
+                cfg.CreateMap<SourceListItemType, TargetListItemType>().ReverseMap();
+                cfg.CreateMap<SourceListItemType, TargetChildListItemType>().ReverseMap();
+
+            }).CreateMapper();
+            Expression<Func<SourceType, bool>> sourcesWithListItemsExpr = src => src.Id != 0 && src.ItemList.FirstOrDefault(i => i.Id == 1) == null && src.Child.ItemList.FirstOrDefault(i => i.Id == 1) == null; // Sources with non-empty ItemList
+
+            // Act
+            Expression<Func<TargetType, bool>> target1sWithListItemsExpr = mapper.MapExpression<Expression<Func<TargetType, bool>>>(sourcesWithListItemsExpr);
+
+            //Assert
+            Assert.NotNull(target1sWithListItemsExpr);
+        }
+
+        private class SourceChildType
+        {
+            public int Id { get; set; }
+            public IEnumerable<SourceListItemType> ItemList { get; set; } // Uses same type (SourceListItemType) for its itemlist as SourceType
+        }
+
+        private class SourceType
+        {
+            public int Id { get; set; }
+            public SourceChildType Child { set; get; }
+            public IEnumerable<SourceListItemType> ItemList { get; set; }
+        }
+
+        private class SourceListItemType
+        {
+            public int Id { get; set; }
+        }
+
+        private class TargetChildType
+        {
+            public virtual int Id { get; set; }
+            public virtual ICollection<TargetChildListItemType> ItemList { get; set; } = [];
+        }
+
+        private class TargetChildListItemType
+        {
+            public virtual int Id { get; set; }
+        }
+
+        private class TargetType
+        {
+            public virtual int Id { get; set; }
+
+            public virtual TargetChildType Child { get; set; }
+
+            public virtual ICollection<TargetListItemType> ItemList { get; set; } = [];
+        }
+
+        private class TargetListItemType
+        {
+            public virtual int Id { get; set; }
+        }
+    }
+}

tests/AutoMapper.Extensions.ExpressionMapping.UnitTests/XpressionMapperTests.cs

@@ -19,6 +19,36 @@ public XpressionMapperTests()
 
         #region Tests
 
+        [Fact]
+        public void Map_expression_list()
+        {
+            //Arrange
+            ICollection<Expression<Func<UserModel, object>>> selections = [s => s.AccountModel.Bal, s => s.AccountName];
+
+            //Act
+            List<Expression<Func<User, object>>> selectionsMapped = [.. mapper.MapExpressionList<Expression<Func<User, object>>>(selections)];
+            List<object> accounts = [.. Users.Select(selectionsMapped[0])];
+            List<object> branches = [.. Users.Select(selectionsMapped[1])];
+
+            //Assert
+            Assert.True(accounts.Count == 2 && branches.Count == 2);
+        }
+
+        [Fact]
+        public void Map_expression_list_using_two_generic_arguments_override()
+        {
+            //Arrange
+            ICollection<Expression<Func<UserModel, object>>> selections = [s => s.AccountModel.Bal, s => s.AccountName];
+
+            //Act
+            List<Expression<Func<User, object>>> selectionsMapped = [.. mapper.MapExpressionList<Expression < Func<UserModel, object>>, Expression <Func<User, object>>>(selections)];
+            List<object> accounts = [.. Users.Select(selectionsMapped[0])];
+            List<object> branches = [.. Users.Select(selectionsMapped[1])];
+
+            //Assert
+            Assert.True(accounts.Count == 2 && branches.Count == 2);
+        }
+
         [Fact]
         public void Map_object_type_change()
         {
@@ -895,6 +925,16 @@ public void Can_map_expression_with_condittional_logic_while_deflattening()
             Assert.NotNull(mappedExpression);
         }
 
+        [Fact]
+        public void Returns_null_when_soure_is_null()
+        {
+            Expression<Func<TestDTO, bool>> expr = null;
+
+            var mappedExpression = mapper.MapExpression<Expression<Func<TestEntity, bool>>>(expr);
+
+            Assert.Null(mappedExpression);
+        }
+
         [Fact]
         public void Can_map_expression_with_multiple_destination_parameters_of_the_same_type()
         {