InMemory database throws exception in .NET5

Upgrading to .NET5 here and there seems to be an exception that I did not encounter with .NETCore3.1:

System.ArgumentException
must be reducible node
   at System.Linq.Expressions.Expression.ReduceAndCheck()
   at System.Linq.Expressions.Expression.ReduceExtensions()
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteExtensionExpression(Expression expr, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteExpression(Expression node, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.ChildRewriter.Add(Expression expression)
   at System.Linq.Expressions.Compiler.StackSpiller.ChildRewriter.AddArguments(IArgumentProvider expressions)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteMethodCallExpression(Expression expr, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteExpression(Expression node, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.ChildRewriter.Add(Expression expression)
   at System.Linq.Expressions.Compiler.StackSpiller.ChildRewriter.AddArguments(IArgumentProvider expressions)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteMethodCallExpression(Expression expr, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteExpression(Expression node, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.RewriteExpressionFreeTemps(Expression expression, Stack stack)
   at System.Linq.Expressions.Compiler.StackSpiller.Rewrite[T](Expression`1 lambda)
   at System.Linq.Expressions.Expression`1.Accept(StackSpiller spiller)
   at System.Linq.Expressions.Compiler.LambdaCompiler.Compile(LambdaExpression lambda)
   at System.Linq.Expressions.Expression`1.Compile()
   at System.Linq.EnumerableQuery`1.GetEnumerator()
   at System.Linq.EnumerableQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator()
   at System.Linq.Enumerable.SelectEnumerableIterator`2.ToArray()
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at FlexLabs.EntityFrameworkCore.Upsert.Runners.InMemoryUpsertCommandRunner.FindMatches[TEntity](IEntityType entityType, IEnumerable`1 entities, DbContext dbContext, Expression`1 matchExpression)
   at FlexLabs.EntityFrameworkCore.Upsert.Runners.InMemoryUpsertCommandRunner.RunCore[TEntity](DbContext dbContext, IEntityType entityType, ICollection`1 entities, Expression`1 matchExpression, Expression`1 updateExpression, Expression`1 updateCondition, RunnerQueryOptions queryOptions)
   at FlexLabs.EntityFrameworkCore.Upsert.Runners.InMemoryUpsertCommandRunner.Run[TEntity](DbContext dbContext, IEntityType entityType, ICollection`1 entities, Expression`1 matchExpression, Expression`1 updateExpression, Expression`1 updateCondition, RunnerQueryOptions queryOptions)
   at FlexLabs.EntityFrameworkCore.Upsert.UpsertCommandBuilder`1.Run()

Code that causes this:

dbContext.Set<Entity>().Upsert(entity).On(x => x.Name).Run();

where Entity:

public class Entity
{
	public Guid Id { get; set; }

	public string Name { get; set; } = default!;
}

There’s actually a bit more code there but I am thinking it is not relevant due to this working in .NETCore3.1. However, please do let me know if you require more to help diagnose this issue and I will do my best to see if I can get it to you. 👍

[artiomchi]

Seems like this is a regression in the expression compiler in the InMemory EF Core driver, which is unfortunate.

I was hoping to avoid something like @RomanGolovanov’s solution, as it converts the whole DbSet into an in memory list, but I don’t really see another alternative here.

I’m merging your commit into the project, as it seems to sort out this problem. Thanks for providing it here!

[tinduong]

@RomanGolovanov Thank you for a quick response. I will try this out…