c# - More than twenty 'IServiceProvider'. Unit Test

Question

I have this error message :

An error was generated for warning 'Microsoft.EntityFrameworkCore.Infrastructure.ManyServiceProvidersCreatedWarning': More than twenty 'IServiceProvider' instances have been created for internal use by Entity Framework. This is commonly caused by injection of a new singleton service instance into every DbContext instance. For example, calling 'UseLoggerFactory' passing in a new instance each time--see https://go.microsoft.com/fwlink/?linkid=869049 for more details. This may lead to performance issues, consider reviewing calls on 'DbContextOptionsBuilder' that may require new service providers to be built. This exception can be suppressed or logged by passing event ID 'CoreEventId.ManyServiceProvidersCreatedWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.

When I run all Unit Test together

Setup

private readonly DbContextOptions<ApplicationDbContext> _contextOptions;
private readonly DbContextOptions<ApplicationDbContext> _inMemoryContextOptions;

public TestConstructor()
{
// Test for real database READ
_contextOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
.UseSqlServer(_connectionString)
.Options;

// Test InMemory CREATE UPDATE DELETE
_inMemoryContextOptions = DbContextOptionsBuilder();
SeedInMemoryTestDb(_inMemoryContextOptions);
}

private static DbContextOptions<ApplicationDbContext> DbContextOptionsBuilder()
{
return new DbContextOptionsBuilder<ApplicationDbContext>()
.UseInMemoryDatabase(Guid.NewGuid().ToString(),new InMemoryDatabaseRoot())
.Options;
}

Unit Test

[FACT] 
public void Test1()
await using var context = new ApplicationDbContext(_contextOptions);
//... Assert.Equal()
[FACT] 
public void Test2()
await using var context = new ApplicationDbContext(_inMemoryContextOptions);
//... Assert.Equal()

I have both Setup and Unit Test in 5 or 6 class. I think I need to re-use the same context for every test but I don't achieve to do that.

question from:https://stackoverflow.com/questions/65860753/more-than-twenty-iserviceprovider-unit-test

Answer 1

[CollectionDefinition("SharedDbContext")]
public class DatabaseCollection : ICollectionFixture<DatabaseFixture> { }

public class DatabaseFixture : IDisposable
{
    public ApplicationDbContext ApplicationDbContext;
    public ApplicationDbContext InMemoryApplicationDbContext;


    public DatabaseFixture()
    {
        // Test for real database READ
        var contextOptions = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseSqlServer(_connectionString)
            .Options;
        //// Test InMemory CREATE UPDATE DELETE
        var inMemoryContextOptions = DbContextOptionsBuilder();

        ApplicationDbContext = new ApplicationDbContext(contextOptions);
        InMemoryApplicationDbContext = new ApplicationDbContext(inMemoryContextOptions);

        SeedInMemoryTestDb(inMemoryContextOptions);
    }
}