Merge pull request #94 from Erythnul/issue93

Resolve Issue 93

Author: BlaiseD

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
 
     - name: Set Variables
       run: |
-        echo '::set-env name=VERSION_NUMBER::4.0.2-preview-1'
+        echo '::set-env name=VERSION_NUMBER::4.0.2-preview-2'
         echo '::set-env name=DEPLOY_PACKAGE_URL::https://www.myget.org/F/automapperdev/api/v3/index.json'
         echo '::set-env name=DEPLOY_PACKAGE_API_KEY::${{ secrets.MYGET_CI_API_KEY }}'
         echo '::set-env name=REPO::${{ github.repository }}'

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
 
     - name: Set Variables
       run: |
-        echo '::set-env name=VERSION_NUMBER::4.0.2-preview-1'
+        echo '::set-env name=VERSION_NUMBER::4.0.2-preview-2'
         echo '::set-env name=DEPLOY_PACKAGE_URL::https://api.nuget.org/v3/index.json'
         echo '::set-env name=DEPLOY_PACKAGE_API_KEY::${{ secrets.NUGET_API_KEY }}'
         echo '::set-env name=REPO::${{ github.repository }}'

Directory.Build.props

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <Authors>Jimmy Bogard</Authors>
     <LangVersion>latest</LangVersion>
-    <VersionPrefix>4.0.2-preview-1</VersionPrefix>
+    <VersionPrefix>4.0.2-preview-2</VersionPrefix>
     <WarningsAsErrors>true</WarningsAsErrors>
     <NoWarn>$(NoWarn);1701;1702;1591</NoWarn>
   </PropertyGroup>

src/AutoMapper.Extensions.ExpressionMapping/XpressionMapperVisitor.cs

@@ -305,12 +305,16 @@ Expression DoVisitUnary(Expression updated)
 
         protected override Expression VisitConstant(ConstantExpression node)
         {
-            if (this.TypeMappings.TryGetValue(node.Type, out Type newType)
-                && ConfigurationProvider.ResolveTypeMap(node.Type, newType) != null)
-                return base.VisitConstant(Expression.Constant(Mapper.MapObject(node.Value, node.Type, newType), newType));
-            //Issue 3455 (Non-Generic Mapper.Map failing for structs in v10)
-            //return base.VisitConstant(Expression.Constant(Mapper.Map(node.Value, node.Type, newType), newType));
+            if (this.TypeMappings.TryGetValue(node.Type, out Type newType))
+            {
+                if (node.Value == null)
+                    return base.VisitConstant(Expression.Constant(null, newType));
 
+                if (ConfigurationProvider.ResolveTypeMap(node.Type, newType) != null)
+                    return base.VisitConstant(Expression.Constant(Mapper.MapObject(node.Value, node.Type, newType), newType));
+                //Issue 3455 (Non-Generic Mapper.Map failing for structs in v10)
+                //return base.VisitConstant(Expression.Constant(Mapper.Map(node.Value, node.Type, newType), newType));
+            }
             return base.VisitConstant(node);
         }
 

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

@@ -34,6 +34,27 @@ public void Issue85()
             Assert.NotNull(mapped2);
         }
 
+        [Fact]
+        public void Issue93()
+        {
+            var config = new MapperConfiguration(cfg =>
+            {
+                cfg.AddExpressionMapping();
+
+                cfg.CreateMap<Source, SourceDto>()
+                    .ForMember(o => o.Items, config => config.MapFrom(p => p.Items.Select(s => s.Name)));
+            });
+
+            var mapper = config.CreateMapper();
+
+            Expression<Func<SourceDto, bool>> expression1 =
+                src => ((src != null ? src : null) != null) && src.Items.Any(x => x == "item1");
+ 
+            var mapped1 = mapper.MapExpression<Expression<Func<Source, bool>>>(expression1);
+
+            Assert.NotNull(mapped1);
+        }
+
         public class Source { public ICollection<SubSource> Items { get; set; } }
 
         public class SubSource { public int ID { get; set; } public string Name { get; set; } }