Bug in TermsQueryDescriptor when passing to Terms IEnumerable<TValue>

[alekole]

if i have some descriptor like
var descr = new QueryContainerDescriptor<SearchProductCard>().Terms(t => t.Field("field").Terms(new List<int> {1,2}));

it will transfer in

"terms": {
     "field": [
        [
             "1",
             "2"
         ]
      ]
   }

This causes an error in elastic

"reason": {
               "type": "number_format_exception",
               "reason": "For input string: \"[\""
            }

I have noticed that before commit e1e467e2 there was an explicit conversion to array

public TermsQueryDescriptor<T, K> Terms(IEnumerable<K> terms) => Assign(a =>  
    {
    if (terms.HasAny())
    terms = terms.Where(t => t != null).ToArray();
    a.Terms = terms.Cast<object>();
});

and missed later

public TermsQueryDescriptor<T, TValue> Terms(IEnumerable<TValue> terms) => Assign(a => a.Terms = terms.Cast<object>());

[tormodu]

I am also experiencing this using Elasticsearch 2.2.|

[russcam]

@alekole, Thanks for reporting. The TermsQueryDescriptor<T> looks like the following

    public class TermsQueryDescriptor<T> 
        : FieldNameQueryDescriptorBase<TermsQueryDescriptor<T>, ITermsQuery, T>
        , ITermsQuery where T : class
    {
        protected override bool Conditionless => TermsQuery.IsConditionless(this);
        MinimumShouldMatch ITermsQuery.MinimumShouldMatch { get; set; }
        bool? ITermsQuery.DisableCoord { get; set; }
        IEnumerable<object> ITermsQuery.Terms { get; set; }
        IFieldLookup ITermsQuery.TermsLookup { get; set; }

        public TermsQueryDescriptor<T> TermsLookup<TOther>(Func<FieldLookupDescriptor<TOther>, IFieldLookup> selector)
            where TOther : class => Assign(a => a.TermsLookup = selector(new FieldLookupDescriptor<TOther>()));

        public TermsQueryDescriptor<T> MinimumShouldMatch(MinimumShouldMatch minMatch) => Assign(a => a.MinimumShouldMatch = minMatch);

        public TermsQueryDescriptor<T> DisableCoord(bool? disable = true) => Assign(a => a.DisableCoord = disable);

        public TermsQueryDescriptor<T> Terms<TValue>(IEnumerable<TValue> terms) => Assign(a => a.Terms = terms?.Cast<object>());

        public TermsQueryDescriptor<T> Terms<TValue>(params TValue[] terms) => Assign(a => a.Terms = terms?.Cast<object>());

    }

The problem that you are experiencing here is that the compiler is preferring the params TValue[] overload of Terms<TValue>(), incorrectly inferring the type of TValue to be List<int> instead of correctly inferring it to be int. Specifying the type of TValue explicitly will rectify this

var descr = new QueryContainerDescriptor<SearchProductCard>().Terms(t => t
    .Field("field")
    // specify generic parameter type to be int
    .Terms<int>(new List<int> {1,2})
);

The Terms<TValue>(IEnumerable<TValue> terms) overload will now be called instead.

/cc @Mpdreamz, @gmarz

[Mpdreamz]

Thanks for reporting this one @tormodu 👍 whilst what we did was technically correct, it is very much unexpected behaviour from a users perspective

I just opened #1948 to try an manually unwrap these cases to "the right thing".