Sample unit test using EF Core and SQL Lite In-Memory provider

EFCoreSQLLiteInMemoryTest.cs

[Fact]
public void GetClients_WhenCalledWithSqlLiteInMemoryDataContext_ReturnsExpectedResult()
{
    var connection = new SqliteConnection("DataSource=:memory:");
    connection.Open();

    try
    {
        var sqlLiteDataContextOptions = new DbContextOptionsBuilder<EventDataContext>()
            .UseSqlite(connection)
            .Options;

        // This will update the database with the current schema for the test
        using (var context = new EventDataContext(sqlLiteDataContextOptions))
        {
            context.Database.EnsureCreated();
        }

        // Need to add a record with the given data context configuration, 
        // in this case, SQL Lite.
        CreateTestClient(sqlLiteDataContextOptions);

        using (var eventDataContext = new EventDataContext(sqlLiteDataContextOptions))
        {
            // Need to inject a separate data context into the controller, 
            // then the results will be asserted against the current records
            var controller = new ClientsController(eventDataContext);

            OkObjectResult okResult = Assert.IsType<OkObjectResult>(controller.GetClients());
            List<Client> returnSession = Assert.IsType<List<Client>>(okResult.Value);

            Assert.True(returnSession.FirstOrDefault().LastName == "last");
        }
    }
    finally
    {
        connection.Close();
    }
}