EfCoreDbSchemaRetriever does not manage it's cache with dependency injection

Hi,

im using this library and just parallelised the test execution of all of my EF Core tests. But while doing this, I hit the following error:

 Message: 
  Initialization method Ofcas.Odid.IntegrationTests.CoreTest.ServicesTest.AddressServiceTest.TestInitialize threw exception. System.ArgumentException: An item with the same key has already been added. Key: Ofcas.Odid.Core.Entities.AddressEntity.

  Stack Trace: 
    Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
    Dictionary`2.Add(TKey key, TValue value)
    EfCoreDbSchemaRetriever.GetTableName(Type entity)
    TriggerMethodCallConverter.Visit(MethodCallExpression expression, ArgumentTypes argumentTypes, VisitedMembers visitedMembers) line 27
    MethodCallExpressionVisitor.Visit(MethodCallExpression expression, ArgumentTypes argumentTypes, VisitedMembers visitedMembers)
    ExpressionVisitorFactory.Visit[TExpression](TExpression expression, ArgumentTypes argumentTypes, VisitedMembers visitedMembers)
    ExpressionVisitorFactory.Visit(Expression expression, ArgumentTypes argumentTypes, VisitedMembers visitedMembers)
    TriggerRawActionVisitor.Visit(TriggerRawAction triggerAction, VisitedMembers visitedMembers)
    TriggerActionVisitorFactory.Visit[T](T triggerAction, VisitedMembers visitedMembers)
    TriggerActionVisitorFactory.Visit(ITriggerAction triggerAction, VisitedMembers visitedMembers)
    SqliteTriggerVisitor.<GenerateCreateTriggerSql>b__3_0(ITriggerAction action)
    SelectListIterator`2.ToArray()
    SqliteTriggerVisitor.GenerateCreateTriggerSql(ITrigger trigger)
    MigrationsExtensions.ConvertTriggerAnnotationsToSql(ITriggerVisitor triggerVisitor, IModel model)
    MigrationsModelDiffer.GetDifferences(IRelationalModel source, IRelationalModel target)
    RelationalDatabaseCreator.GetCreateTablesCommands(MigrationsSqlGenerationOptions options)
    RelationalDatabaseCreator.CreateTables()
    SQLiteConnectionTestHelper.TestInitialize() line 53

I am using a custom MethodCallConverter called TriggerMethodCallConverter, which injects IDbSchemaRetriever.

public class TriggerMethodCallConverter : BaseMethodCallVisitor
{
    private readonly IDbSchemaRetriever _dbSchemaRetriever;

    protected override Type ReflectedType => typeof(TriggerFunctions);

    protected override string MethodName => nameof(TriggerFunctions.GetDbTableName);

    public TriggerMethodCallConverter(IDbSchemaRetriever dbSchemaRetriever, IExpressionVisitorFactory visitorFactory) : base(visitorFactory)
    {
        _dbSchemaRetriever = dbSchemaRetriever;
    }

    public override SqlBuilder Visit(MethodCallExpression expression, ArgumentTypes argumentTypes, VisitedMembers visitedMembers)
    {
        var genericArguments = expression.Method.GetGenericArguments();
        return SqlBuilder.FromString(_dbSchemaRetriever.GetTableName(genericArguments[0]));
    }
}

Because IDbSchemaRetriever.GetTableName caches the table names in a static variable, I assume i run into a race condition here:

https://github.com/win7user10/Laraue.EfCoreTriggers/blob/e30ecb03d5bb1ec4ea7d0057c331eb1a623c3a5f/src/Laraue.EfCoreTriggers.Common/Services/Impl/EfCoreDbSchemaRetriever.cs#L68-L74

I think instead of a static variable, the cache should be managed by the dependency injection container of EFCore. Then each of my DbContexts will have a different cache.

The other option would be to use a concurrent dictionary, but I feel like that is not 100% clean.

Furthermore you might still need a concurrent dictionary using the first option, I am not 100% sure how the concurrency guarantees are, if two DbContext instances share the same dependency container.

win7user10 / Laraue.EfCoreTriggers

EfCoreDbSchemaRetriever does not manage it's cache with dependency injection #58