Linq All on empty collection

Question

I need to check if all definitions contains some specific data. It works fine except the case when GroupBy returns empty collection.

var exist = dbContext.De         


        

Answer 1

What about writing your own extension method? (I am pretty sure you will name it better)

public static bool NotEmptyAll(
    this IEnumerable collection, 
    Func predicate)
{
    return collection != null
        && collection.Any()
        && collection.All(predicate);
}

Then call it instead of All

var exist = definitions.Where(
        x => propertyTypeIds.Contains(x.PropertyTypeId) && x.CountryId == countryId)
         .GroupBy(x => x.PropertyTypeId)
         .NotEmptyAll(
             ...some condition...));