public IQueryable <TElement> CreateQuery <TElement>(Expression expression)
{
if (expression.NodeType == ExpressionType.Call)
{
MethodCallExpression callExpression = (MethodCallExpression)expression;
if (callExpression.Method.Name == "Select" &&
callExpression.Method.GetParameters().Length == 2 &&
callExpression.Method.GetParameters()[0].ParameterType == typeof(IQueryable <T>) &&
callExpression.Method.GetParameters()[1].ParameterType == typeof(Expression <Func <T, TElement> >))
{
Expression <Func <T, TElement> > selector = ((UnaryExpression)callExpression.Arguments[1]).Operand as Expression <Func <T, TElement> >;
return(new SelectQueryable <TElement, T>(
Expression.Lambda <Func <IQueryable <T> > >(callExpression.Arguments[0]).Compile()(),
selector.Compile()));
}
if (typeof(T) != typeof(TElement))
{
throw new ApplicationException("Queryable and ObjectProviderType does not match.");
}
Expression[] arguments = new Expression[callExpression.Arguments.Count];
bool replaced = false;
for (int i = 0; i < callExpression.Arguments.Count; i++)
{
if (i == 0 && typeof(IQueryable).IsAssignableFrom(callExpression.Arguments[0].Type))
{
arguments[0] = callExpression.Arguments[0];
}
else
{
arguments[i] = ExpressionHelper.ReplaceExpressionParts(callExpression.Arguments[i],
x => x.NodeType == ExpressionType.Constant ||
ExpressionHelper.ContainsAny(x, y => y.NodeType == ExpressionType.Parameter) ?
x :
Expression.Constant(LambdaExpression.Lambda(x).Compile().DynamicInvoke(), x.Type));
}
replaced = replaced || arguments[i] != callExpression.Arguments[i];
}
if (replaced)
{
expression = LambdaExpression.Call(callExpression.Object, callExpression.Method, arguments);
}
}
return((IQueryable <TElement>)Queryable.Create(_objectProvider, expression));
}
public void ContainsAny(Expression <Func <string, string> > expression, Predicate <Expression> predicate, bool expectedValue)
{
bool result = ExpressionHelper.ContainsAny(expression, predicate);
Assert.Equal(expectedValue, result);
}
