GetServiceOrCreateInstance attempts to call wrong constructor when no types registered in D.I.

[ajcvickers]

Original issue: dotnet/efcore#23306
/cc @bricelam @davidfowl

Using these types:

public class FailureContext : DbContext
{
    public FailureContext(ILogger<FailureContext> logger)
    {
        Console.WriteLine($"With logger {logger}");
    }

    public FailureContext()
    {
        Console.WriteLine("Parameterless");
    }
}

This works for both GetService<FailureContext> and ActivatorUtilities.GetServiceOrCreateInstance<FailureContext> when both these types are in D.I.:

        var serviceProvider1 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

Output:

With logger MyLogger
With logger MyLogger

It also works if only DbContext is registered in D.I.:

        var serviceProvider1 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

In this case the output shows that the parameterless constructor is used:

Parameterless
Parameterless

It also works if FailureContext is not registered in D.I., but the logger is:

        var serviceProvider1 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

In this case GetService returns null, but GetServiceOrCreateInstance still chooses the correct constructor.

With logger MyLogger

When this fails is when neither the logger or the logger are registered in D..I:

        var serviceProvider1 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

Unhandled exception. System.InvalidOperationException: Unable to resolve service for type 'Microsoft.Extensions.Logging.ILogger`1[FailureContext]' while attempting to activate 'FailureContext'.
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.ConstructorMatcher.CreateInstance(IServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.CreateInstance(IServiceProvider provider, Type instanceType, Object[] parameters)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetServiceOrCreateInstance(IServiceProvider provider, Type type)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetServiceOrCreateInstance[T](IServiceProvider provider)
   at Program.Main(String[] args) in /home/ajcvickers/AllTogetherNow/FiveOh/Program.cs:line 155

In this case, GetServiceOrCreateInstance should choose the parameterless constructor since there is no other constructor that can work, but it it instead fails by attempting to call a constructor for which the parameter cannot be resolved.

[ghost]

Tagging subscribers to this area: @eerhardt, @maryamariyan
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Issue Details

---

Original issue: dotnet/efcore#23306
/cc @bricelam @davidfowl

Using these types:

public class FailureContext : DbContext
{
    public FailureContext(ILogger<FailureContext> logger)
    {
        Console.WriteLine($"With logger {logger}");
    }

    public FailureContext()
    {
        Console.WriteLine("Parameterless");
    }
}

This works for both GetService<FailureContext> and ActivatorUtilities.GetServiceOrCreateInstance<FailureContext> when both these types are in D.I.:

        var serviceProvider1 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

Output:

With logger MyLogger
With logger MyLogger

It also works if only DbContext is registered in D.I.:

        var serviceProvider1 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            .AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

In this case the output shows that the parameterless constructor is used:

Parameterless
Parameterless

It also works if FailureContext is not registered in D.I., but the logger is:

        var serviceProvider1 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            .AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

In this case GetService returns null, but GetServiceOrCreateInstance still chooses the correct constructor.

With logger MyLogger

When this fails is when neither the logger or the logger are registered in D..I:

        var serviceProvider1 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context1 = serviceProvider1.GetService<FailureContext>();

        var serviceProvider2 = new ServiceCollection()
            //.AddSingleton<ILogger<FailureContext>, MyLogger>()
            //.AddSingleton<FailureContext>()
            .BuildServiceProvider();

        var context2 = ActivatorUtilities.GetServiceOrCreateInstance<FailureContext>(serviceProvider2);

Unhandled exception. System.InvalidOperationException: Unable to resolve service for type 'Microsoft.Extensions.Logging.ILogger`1[FailureContext]' while attempting to activate 'FailureContext'.
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.ConstructorMatcher.CreateInstance(IServiceProvider provider)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.CreateInstance(IServiceProvider provider, Type instanceType, Object[] parameters)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetServiceOrCreateInstance(IServiceProvider provider, Type type)
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetServiceOrCreateInstance[T](IServiceProvider provider)
   at Program.Main(String[] args) in /home/ajcvickers/AllTogetherNow/FiveOh/Program.cs:line 155

In this case, GetServiceOrCreateInstance should choose the parameterless constructor since there is no other constructor that can work, but it it instead fails by attempting to call a constructor for which the parameter cannot be resolved.

Author:	ajcvickers
Assignees:	-
Labels:	area-Extensions-DependencyInjection
Milestone:	-

[maryamariyan]

Closing as dupe of #46132 since there is more discussion there