EnableNullChecks is cached unexpectedly?

[gojanpaolo]

The following code passes dotnet test. (Also tried in VS 2022 17.0.0 and same behavior is observed)

using System;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using Xunit;

public class UnitTest1
{
  [Fact]
  public async Task Test1()
  {
    // UNCOMMENT THIS CODE TO FAIL TEST
    // await using var ctx1 = new TestDbContext(
    //   new DbContextOptionsBuilder<TestDbContext>()
    //   .UseInMemoryDatabase(Guid.NewGuid().ToString())
    //   .Options);

    await using var ctx2 = new TestDbContext(
      new DbContextOptionsBuilder<TestDbContext>()
      .UseInMemoryDatabase(Guid.NewGuid().ToString(), _ => _.EnableNullChecks(false))
      .Options);
    await ctx2.Foo.AddAsync(new());
    await ctx2.SaveChangesAsync();
  }
}
public class TestDbContext : DbContext
{
  public TestDbContext(DbContextOptions<TestDbContext> options) : base(options) { }
  public DbSet<Foo> Foo { get; private init; } = null!;
}
public class Foo
{
  public int Id { get; set; }
  public string Bar { get; set; } = null!;
}

csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
    <IsPackable>false</IsPackable>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="6.0.0" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
    <PackageReference Include="xunit" Version="2.4.1" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
  </ItemGroup>
</Project>

But uncommenting the code as described in the code fails dotnet test

$ dotnet test
  Determining projects to restore...
  All projects are up-to-date for restore.
  efcore6 -> C:\Users\gojan\sb\efcore6\bin\Debug\net6.0\efcore6.dll
Test run for C:\Users\gojan\sb\efcore6\bin\Debug\net6.0\efcore6.dll (.NETCoreApp,Version=v6.0)
Microsoft (R) Test Execution Command Line Tool Version 17.0.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
[xUnit.net 00:00:00.82]     UnitTest1.Test1 [FAIL]
  Failed UnitTest1.Test1 [378 ms]
  Error Message:
   Microsoft.EntityFrameworkCore.DbUpdateException : Required properties '{'Bar'}' are missing for the instance of entity type 'Foo'. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the entity key value.
  Stack Trace:
     at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryTable`1.ThrowNullabilityErrorException(IUpdateEntry entry, IList`1 nullabilityErrors)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryTable`1.Create(IUpdateEntry entry)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryStore.ExecuteTransaction(IList`1 entries, IDiagnosticsLogger`1 updateLogger)
   at Microsoft.EntityFrameworkCore.InMemory.Storage.Internal.InMemoryDatabase.SaveChangesAsync(IList`1 entries, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(StateManager stateManager, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
   at UnitTest1.Test1() in C:\Users\gojan\sb\efcore6\UnitTest1.cs:line 22
   at UnitTest1.Test1() in C:\Users\gojan\sb\efcore6\UnitTest1.cs:line 22
   at UnitTest1.Test1() in C:\Users\gojan\sb\efcore6\UnitTest1.cs:line 22
--- End of stack trace from previous location ---

Failed!  - Failed:     1, Passed:     0, Skipped:     0, Total:     1, Duration: < 1 ms - efcore6.dll (net6.0)

---

My expected behavior is that EnableNullChecks can be configured differently for each DbContextOptions instance. Thank you

---

Operating system: Windows 10

[ajcvickers]

Note for triage: this should be a singleton option and cause a service provider re-build if changed.