public void ChangeBinaryToMethodCall()
{
var addresses = Expression.MakeMemberAccess(
Expression.Parameter(typeof(Person), "person"),
typeof(Person).GetProperty(nameof(Person.Addresses)));
var count = Expression.MakeMemberAccess(addresses, typeof(Address).GetProperty("Count"));
// person.PersonId == "1"
BinaryExpression personIdEqualsOne =
Expression.MakeBinary(
ExpressionType.Equal,
Expression.MakeMemberAccess(
Expression.Parameter(typeof(Person), "person"),
typeof(Person).GetProperty(nameof(Person.PersonId))),
Expression.Constant("1"));
// person.PersonId
Expression personId = personIdEqualsOne.Left;
// person.Addresses
MemberExpression personAddresses = new ChangeMemberProperty(
typeof(Person),
personId,
nameof(Person.Addresses))
.Change();
// Select method
MethodInfo selectMethod = EnumerableMethodInfo.Select <Address, int>();
// address
ParameterExpression addressParam = Expression.Parameter(typeof(Address), "address");
// address.AddressId
MemberExpression memberAccess = Expression.MakeMemberAccess(
addressParam,
typeof(Address).GetProperty(nameof(Address.AddressId)));
// address => address.AddressId
LambdaExpression lambda = Expression.Lambda(
memberAccess,
addressParam
);
// person.Addresses.Select(address => address.AddressId)
MethodCallExpression selectAddresses = Expression.Call(selectMethod, new List <Expression> {
personAddresses, lambda
});
Assert.NotNull(selectAddresses);
}
public void ChangeMemberAccess()
{
MemberExpression personId = Expression.MakeMemberAccess(
Expression.Parameter(typeof(Person)),
typeof(Person).GetProperty(nameof(Person.PersonId)));
Expression personLastName = new ChangeMemberProperty(typeof(Person),
personId,
nameof(Person.LastName))
.Change();
Assert.IsAssignableFrom <MemberExpression>(personLastName);
Assert.Equal(nameof(Person.LastName), ((MemberExpression)personLastName).Member.Name);
}
public void ChangeNestedMemberAccess()
{
MemberExpression personId = Expression.MakeMemberAccess(
Expression.Parameter(typeof(Person)),
typeof(Person).GetProperty(nameof(Person.PersonId)));
MemberExpression personAddresses = new ChangeMemberProperty(
typeof(Person),
personId,
nameof(Person.Addresses))
.Change();
// todo: fix to work with collection property accessors
MemberExpression newMember = Expression.MakeMemberAccess(
personAddresses,
personAddresses.Type.GetProperty(nameof(Address.AddressId)));
Assert.IsAssignableFrom <MemberExpression>(newMember);
Assert.Equal(nameof(Address.AddressId), newMember.Member.Name);
}