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Merged
merged 4 commits into from
Jul 25, 2018
Merged

Use 0 instead of GetHashCode() when member is null #104

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527c0ea
Remove version missmatch reference
Tasteful Jul 25, 2018
5f81fe6
Add tests for nullable keys
Tasteful Jul 25, 2018
1b369b5
add if expression to use 0 instead of throw NRE when member is null
Tasteful Jul 25, 2018
98d9268
Update test to include multiple new entities and also a remove
Tasteful Jul 25, 2018
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4 changes: 0 additions & 4 deletions ...apper.Collection.EntityFramework.Tests/AutoMapper.Collection.EntityFramework.Tests.csproj
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Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,6 @@
<IsPackable>false</IsPackable>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="System.ValueTuple" Version="4.3.0" />
</ItemGroup>

<ItemGroup>
<ProjectReference Include="..\AutoMapper.Collection.EntityFramework\AutoMapper.Collection.EntityFramework.csproj" />
</ItemGroup>
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82 changes: 82 additions & 0 deletions src/AutoMapper.Collection.Tests/NullableIdTests.cs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,82 @@
using System.Collections.Generic;
using AutoMapper.EquivalencyExpression;
using FluentAssertions;
using Xunit;

namespace AutoMapper.Collection
{
public class NullableIdTests
{
[Fact]
public void Should_Work_With_Null_Id()
{
Mapper.Reset();
Mapper.Initialize(x =>
{
x.AddCollectionMappers();
x.CreateMap<ThingWithStringIdDto, ThingWithStringId>().EqualityComparison((dto, entity) => dto.ID == entity.ID);
});

var original = new List<ThingWithStringId>
{
new ThingWithStringId { ID = "1", Title = "test0" },
new ThingWithStringId { ID = "2", Title = "test2" },
};

var dtos = new List<ThingWithStringIdDto>
{
new ThingWithStringIdDto { ID = "1", Title = "test0" },
new ThingWithStringIdDto { ID = "2", Title = "test2" },
new ThingWithStringIdDto { Title = "test3" }
};

Mapper.Map(dtos, original);

original.Should().HaveSameCount(dtos);
}


[Fact]
public void Should_Work_With_Multiple_Null_Id()
{
Mapper.Reset();
Mapper.Initialize(x =>
{
x.AddCollectionMappers();
x.CreateMap<ThingWithStringIdDto, ThingWithStringId>().EqualityComparison((dto, entity) => dto.ID == entity.ID);
});

var original = new List<ThingWithStringId>
{
new ThingWithStringId { ID = "1", Title = "test0" },
new ThingWithStringId { ID = "2", Title = "test2" },
new ThingWithStringId { ID = "3", Title = "test3" },
};

var dtos = new List<ThingWithStringIdDto>
{
new ThingWithStringIdDto { ID = "1", Title = "test0" },
new ThingWithStringIdDto { ID = "2", Title = "test2" },
new ThingWithStringIdDto { Title = "test3" },
new ThingWithStringIdDto { Title = "test4" },
};

Mapper.Map(dtos, original);

original.Should().HaveSameCount(dtos);
}

public class ThingWithStringId
{
public string ID { get; set; }
public string Title { get; set; }
public override string ToString() { return Title; }
}

public class ThingWithStringIdDto
{
public string ID { get; set; }
public string Title { get; set; }
}
}
}
35 changes: 22 additions & 13 deletions src/AutoMapper.Collection/EquivalencyExpression/ExpressionExtentions.cs
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Original file line number Diff line number Diff line change
@@ -1,7 +1,6 @@
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using AutoMapper.Collection;
Expand All @@ -16,30 +15,30 @@ public static Type GetSinglePredicateExpressionArgumentType(this Type type)
{
return _singleParameterTypeDictionary.GetOrAdd(type, t =>
{
var isExpression = typeof (Expression).GetTypeInfo().IsAssignableFrom(t.GetTypeInfo());
var isExpression = typeof(Expression).GetTypeInfo().IsAssignableFrom(t.GetTypeInfo());
if (!isExpression)
return null;

var expressionOf = t.GetTypeInfo().GenericTypeArguments.First();
var isFunction = expressionOf.GetGenericTypeDefinition() == typeof (Func<,>);
var expressionOf = t.GetTypeInfo().GenericTypeArguments[0];
var isFunction = expressionOf.GetGenericTypeDefinition() == typeof(Func<,>);
if (!isFunction)
return null;

var isPredicate = expressionOf.GetTypeInfo().GenericTypeArguments[1] == typeof (bool);
var isPredicate = expressionOf.GetTypeInfo().GenericTypeArguments[1] == typeof(bool);
if (!isPredicate)
return null;

var objType = expressionOf.GetTypeInfo().GenericTypeArguments.First();
var objType = expressionOf.GetTypeInfo().GenericTypeArguments[0];
return CacheAndReturnType(type, objType);
});
}

private static Type CacheAndReturnType(Type type, Type objType)
{
_singleParameterTypeDictionary.AddOrUpdate(type, objType, (t,t2) => objType);
_singleParameterTypeDictionary.AddOrUpdate(type, objType, (_, __) => objType);
return objType;
}

public static Expression<Func<T, int>> GetHashCodeExpression<T>(this List<Expression> members, ParameterExpression sourceParam)
{
var hashMultiply = Expression.Constant(397L);
Expand All @@ -48,20 +47,30 @@ public static Expression<Func<T, int>> GetHashCodeExpression<T>(this List<Expres
var returnTarget = Expression.Label(typeof(int));
var returnExpression = Expression.Return(returnTarget, Expression.Convert(hashVariable, typeof(int)), typeof(int));
var returnLabel = Expression.Label(returnTarget, Expression.Constant(-1));

var expressions = new List<Expression>();
foreach (var member in members)
{
var callGetHashCode = Expression.Call(member, member.Type.GetDeclaredMethod(nameof(GetHashCode)));
var convertHashCodeToInt64 = Expression.Convert(callGetHashCode, typeof(long));
// Call the GetHashCode method
var hasCodeExpression = Expression.Convert(Expression.Call(member, member.Type.GetDeclaredMethod(nameof(GetHashCode))), typeof(long));

// return (((object)x) == null ? 0 : x.GetHashCode())
var hashCodeReturnTarget = Expression.Label(typeof(long));
var hashCode = Expression.Block(
Expression.IfThenElse(
Expression.ReferenceEqual(Expression.Convert(member, typeof(object)), Expression.Constant(null)),
Expression.Return(hashCodeReturnTarget, Expression.Constant(0L, typeof(long))),
Expression.Return(hashCodeReturnTarget, hasCodeExpression)),
Expression.Label(hashCodeReturnTarget, Expression.Constant(0L, typeof(long))));

if (expressions.Count == 0)
{
expressions.Add(Expression.Assign(hashVariable, convertHashCodeToInt64));
expressions.Add(Expression.Assign(hashVariable, hashCode));
}
else
{
var oldHashMultiplied = Expression.Multiply(hashVariable, hashMultiply);
var xOrHash = Expression.ExclusiveOr(oldHashMultiplied, convertHashCodeToInt64);
var xOrHash = Expression.ExclusiveOr(oldHashMultiplied, hashCode);
expressions.Add(Expression.Assign(hashVariable, xOrHash));
}
}
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