Override is linq to objects

[david-garcia-garcia]

Current implementation of IsLinqToObjects might no always return the correct result because there is no specificatin or reliable way of actually answering the question "IsLinqToObjects".

I..e in our project we are using LinqKit's AsExpandable() and we had to extend the current implementation by forking:

private static bool IsProviderEnumerableQuery(IQueryProvider provider, IQueryable query)
        {
            Type baseType = provider.GetType().GetTypeInfo().BaseType;

            if (baseType == typeof(EnumerableQuery))
            {
                return true;
            }

            // Support for QueryTranslatorProvider
            if (baseType.Name == "QueryTranslatorProvider")
            {
                try
                {
                    IQueryProvider provider1 = baseType.GetProperty("OriginalProvider").GetValue(provider, (object[])null) as IQueryProvider;
                    return provider1 != null && QueryExtensions.IsProviderEnumerableQuery(provider1, query);
                }
                catch
                {
                    return false;
                }
            }

            // Support for LinqKit's ExpandableQuery
            if (provider.GetType().Name.StartsWith("ExpandableQuery"))
            {
                try
                {
                    IQueryable innerQuery = query.GetType().GetProperty("InnerQuery", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(query) as IQueryable;
                    return innerQuery != null && QueryExtensions.IsProviderEnumerableQuery(innerQuery.Provider, innerQuery);
                }
                catch
                {
                    return false;
                }
            }

            return false;
        }

The proposal is to move IsLinqToObjects to the ParsingConfig object, so that users can customize it depending on what libraries they are using.

This is of course a breaking change as it breaks the current's library public contract.

[codecov]

Codecov Report

Merging #229 into master will increase coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #229      +/-   ##
==========================================
+ Coverage   96.63%   96.64%   +0.01%     
==========================================
  Files          41       41              
  Lines        6654     6683      +29     
==========================================
+ Hits         6430     6459      +29     
  Misses        224      224

Impacted Files	Coverage Δ
...stem.Linq.Dynamic.Core/DefaultQueryableAnalyzer.cs	100% <100%> (ø)
src/System.Linq.Dynamic.Core/ParsingConfig.cs	100% <100%> (ø)	⬆️
...em.Linq.Dynamic.Core/DynamicQueryableExtensions.cs	100% <100%> (ø)	⬆️

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[StefH]

Good point, thanks for the PR.

However I would propose this:

1. Create a new Interface and Default implementation class.
2. Move the logic from IsProviderEnumerableQuery to that class.
3. Create a new property in the ParsingConfig class and build this property like public IExpressionPromoter ExpressionPromoter

For item 1 and 2:
Interface name could be:

public interface IQueryProviderAnalyzer
{
    bool IsProviderEnumerableQuery(IQueryProvider provider)
}

And default implementation is

public class DefaultQueryProviderAnalyzer
{
    public bool IsProviderEnumerableQuery(IQueryProvider provider)
    {
      // copy code from ParsingConfig -> IsProviderEnumerableQuery method here
    }
}

Item 3 would be like:

public IQueryableProviderAnalyzer QueryableProviderAnalyzer
        {
            get
            {
                return _queryableProviderAnalyzer ?? (_queryableProviderAnalyzer = new DefaultQueryableProviderAnalyzer());
            }

            set
            {
                if (_queryableProviderAnalyzer != value)
                {
                    _queryableProviderAnalyzer = value;
                }
            }
}

[StefH]

I will take a look and try to refactor the code...

refactored

[StefH]

@david-garcia-garcia - I did update the code, please take a look.

[StefH]

@david-garcia-garcia : can you please take a look at my updates for this PR?

[david-garcia-garcia]

Looks impecable! Been bussy...