Exception in QueryableMethods, line 197, because .NET 6 has two ElementAt methods with two parameters.

[tehmang]

In .NET 6, there are two ElementAt methods having two parameters: the new one takes an Index as second parameter: Queryable.ElementAt Method
The Single query in line 197 raises the exception "Sequence contains more than one matching element".

A version of CouchDB.Driver.Example built with .NET 6 as target framework, crashes with this exception.

[Sacrilege]

I created a PR for this. #156

[matteobortolazzo]

Hi, I merged the PR in dev.

If you needing asap, I can release a preview package

[tehmang]

Hi,
Thanks for this quick fix !
I saw you also fixed Take method that I forgot to mention in the issue.
I don't need it asap: I also have a local fix which I wanted to submit soon, so I can use it to work on my current dev.
I'll take the official version when you will release it, thanks.

[mwasson74]

Hello,

I am in the process of migrating our app to .NET 6 and am running into a similar issue with FirstOrDefault as below:

var users = _couchContext.Client.GetUsersDatabase<CustomCouchUser>();
var couchUser = users.FirstOrDefault(x => x.Name == "myName");

Associated Stack Trace:

System.TypeInitializationException: The type initializer for 'CouchDB.Driver.Shared.SupportedMethodsProvider' threw an exception.
 ---> System.TypeInitializationException: The type initializer for 'CouchDB.Driver.Shared.QueryableMethods' threw an exception.
 ---> System.InvalidOperationException: Sequence contains more than one matching element
   at System.Linq.ThrowHelper.ThrowMoreThanOneMatchException()
   at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
   at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source, Func`2 predicate)
   at CouchDB.Driver.Shared.QueryableMethods..cctor()
   --- End of inner exception stack trace ---
   at CouchDB.Driver.Shared.QueryableMethods.get_Where()
   at CouchDB.Driver.Shared.SupportedMethodsProvider..cctor()
   --- End of inner exception stack trace ---
   at CouchDB.Driver.Shared.SupportedMethodsProvider.IsSupportedNativelyOrByComposition(MethodInfo methodInfo)
   at CouchDB.Driver.Query.QueryOptimizer.VisitMethodCall(MethodCallExpression node)
   at CouchDB.Driver.Query.QueryOptimizer.Optimize(Expression e, String discriminator)
   at CouchDB.Driver.Query.QueryCompiler.SendRequestWithFilter[TResult](MethodCallExpression methodCallExpression, Expression query, Boolean async, CancellationToken cancellationToken)
   at CouchDB.Driver.Query.QueryCompiler.SendRequest[TResult](Expression query, Boolean async, CancellationToken cancellationToken)
   at CouchDB.Driver.Query.QueryCompiler.Execute[TResult](Expression query)
   at CouchDB.Driver.Query.CouchQueryProvider.Execute[TResult](Expression expression)
   at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source, Expression`1 predicate)

The Affected APIs include 9 methods and FirstOrDefault() is one of them.

Do you have any suggestions as a workaround until the next release?

Thanks!!

[mwasson74]

FYI - I was able to take @Sacrilege's changes and that fixed my issue for the time being. Apparently, FirstOrDefault() was causing the issue but instead it was what @Sacrilege fixed.

[matteobortolazzo]

@mwasson74 glad to hear. Let me know if you need a preview release of the current dev branch

[TGrannen]

Hey @matteobortolazzo, is there any timeline/roadmap for this fix to be included in a release (or preview release) build? Just started working with this package on a new .NET 6 project, and this gave me quite the headache.

I'm trying to figure out if I should keep going down the path of using this package or switch to something else since it's still early in development. Thanks!

[mp250720]

Hey @matteobortolazzo, is there any timeline/roadmap for this fix to be included in a release (or preview release) build? Just started working with this package on a new .NET 6 project, and this gave me quite the headache.

I'm trying to figure out if I should keep going down the path of using this package or switch to something else since it's still early in development. Thanks!

I second this. A preview package would be awesome. Thanks.

[matteobortolazzo]

@TGrannen sorry I have been very busy in the last months, I hope to get back to it soon.
But I totally release a preview package with the current dev branch!

https://www.nuget.org/packages/CouchDB.NET/3.2.0-Preview

CC @mp250720

[TGrannen]

@matteobortolazzo No problem! I'll pull it down and give it a try tomorrow! Thanks!

[TGrannen]

@matteobortolazzo The preview build seems to be working great with .NET 6! Thanks for the quick resolution!

[mp250720]

Thanks so much!

[tjrobinson]

@matteobortolazzo Thanks for the fix for this. Now that .NET 5 is out of support and .NET 6 is the LTS version - are you be able to push out a non preview version of 3.2.0?

[matteobortolazzo]

Yes it's a good idea, releasing now