ASP.NET Core Testing - get NullReferenceException when initializing InMemory SQLite dbcontext in fixture

Question

I have a test fixture in which I initialize my SQLite in-memory dbcontext, shown below:

public static MYAPPDBContext Create()
{
    var options = new DbContextOptionsBuilder<MYAPPDBContext>()
                    .UseSqlite("DataSource=:memory:")
                    .Options;
    var context = new MYAPPDBContext(options);

    context.Database.OpenConnection(); // this is where exception is thrown
    context.Database.EnsureCreated();

    return context;
}

When I call the Create() method, I get the following NullReferenceException:

System.NullReferenceException
  HResult=0x80004003
  Message=Object reference not set to an instance of an object.
  Source=Microsoft.Data.Sqlite
  StackTrace:
   at Microsoft.Data.Sqlite.SqliteConnection.Open()
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Sqlite.Storage.Internal.SqliteRelationalConnection.Open(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.RelationalDatabaseFacadeExtensions.<>c.<OpenConnection>b__15_0(DatabaseFacade database)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.Execute[TState,TResult](IExecutionStrategy strategy, Func`2 operation, Func`2 verifySucceeded, TState state)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.Execute[TState,TResult](IExecutionStrategy strategy, TState state, Func`2 operation)
   at Microsoft.EntityFrameworkCore.RelationalDatabaseFacadeExtensions.OpenConnection(DatabaseFacade databaseFacade)
   at MYAPPPlus.UnitTests.TestInfrastructure.MYAPPContextFactory.Create() in C:\websites\MYAPPPremier\tests\MYAPPPlus.UnitTests\TestInfrastructure\MYAPPContextFactory.cs:line 26
   at MYAPPPlus.UnitTests.TestInfrastructure.QueryTestFixture..ctor() in C:\websites\MYAPPPremier\tests\MYAPPPlus.UnitTests\TestInfrastructure\QueryTestFixture.cs:line 24

Any ideas on what might be happening?

FYI: I'm basing my code on the blog post at https://garywoodfine.com/entity-framework-core-memory-testing-database/, among other resources. Also, my fixture works just fine when using basic ef core inmemory database.

Answer 1

My bad. I had installed Microsoft.Data.Sqlite.Core version 3.0.0 when I needed version 2.2.6 and I had not installed Microsoft.Data.Sqlite 2.2.6, which I have since installed. It's working now.

Also, FYI: both .UseSqlite("Data Source=:memory:") and .UseSqlite("DataSource=:memory:") work.