public override Expression Apply(Expression expression, Random random)
{
var typeArgument = expression.Type.GetGenericArguments()[0];
var isDescending = random.Next(3) == 0;
var thenBy = isDescending
? ThenByDescendingMethodInfo.MakeGenericMethod(typeArgument, typeArgument)
: ThenByMethodInfo.MakeGenericMethod(typeArgument, typeArgument);
var prm = Expression.Parameter(typeArgument, "prm");
var lambda = Expression.Lambda(prm, prm);
var resultExpression = Expression.Call(thenBy, expression, lambda);
return(resultExpression);
}
public override Expression Apply(Expression expression, Random random)
{
var i = random.Next(_expressionFinder.FoundExpressions.Count);
var expressionToInject = _expressionFinder.FoundExpressions.ToList()[i].Key;
var j = random.Next(_expressionFinder.FoundExpressions[expressionToInject].Count);
var property = _expressionFinder.FoundExpressions[expressionToInject][j];
var typeArgument = expressionToInject.Type.GetGenericArguments()[0];
var isDescending = random.Next(3) == 0;
var thenBy = isDescending
? ThenByDescendingMethodInfo.MakeGenericMethod(typeArgument, property.PropertyType)
: ThenByMethodInfo.MakeGenericMethod(typeArgument, property.PropertyType);
var prm = Expression.Parameter(typeArgument, "prm");
var lambdaBody = (Expression)Expression.Property(prm, property);
if (property.PropertyType.IsValueType &&
!(property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof(Nullable <>)))
{
var nullablePropertyType = typeof(Nullable <>).MakeGenericType(property.PropertyType);
thenBy = isDescending
? ThenByDescendingMethodInfo.MakeGenericMethod(typeArgument, nullablePropertyType)
: ThenByMethodInfo.MakeGenericMethod(typeArgument, nullablePropertyType);
lambdaBody = Expression.Convert(lambdaBody, nullablePropertyType);
}
if (typeArgument == typeof(string))
{
// string.Length - make it nullable in case we access optional argument
thenBy = OrderByMethodInfo.MakeGenericMethod(typeArgument, typeof(int?));
lambdaBody = Expression.Convert(lambdaBody, typeof(int?));
}
var lambda = Expression.Lambda(lambdaBody, prm);
var injector = new ExpressionInjector(expressionToInject, e => Expression.Call(thenBy, e, lambda));
return(injector.Visit(expression));
}
