resolving() events on interfaces are called twice

[tomlankhorst]

In L5.5, 5.6 I experience an issue with resolving callbacks on dependencies registered in the container with an interface class as abstract. A demonstration:

Having some interface

IBar {}

and an implementation

Foo implements IBar {}

registered (here as a singleton) in the container

app()->singleton( IBar::class, Foo::class );

with a resolving callback

app()->resolving( IBar::class, $callback );

fires $callback twice when the abstract is resolved!

This is probably because:

1. When the abstract IBar resolves, it triggers the callback
2. To resolve IBar, Foo must be constructed. As Foo implements IBar, it triggers the resolving event too!

This problem can be omitted when avoiding Laravel's container to build Foo by registering a callback instead:

app()->singleton( IBar::class, f(){ return new Foo; } )

But this abolishes the ease of automatic dependency injection.

So... can we solve this issue by not firing the resolving() callback when we are building the implementation of an interface that the callback is registered for?

[sisve]

There has been some attempts to fix this previously in #23290 but it wasn't merged. Perhaps send a PR with your suggested changes?

[tomlankhorst]

Fine, I'll submit a PR these days that will address this issue.

This test triggers the problem:

    public function testResolvingCallbacksAreCalledOnceForImplementations()
    {
        $invocations = 0;
        $container = new Container;
        $container->resolving( IContainerContractStub::class, function( ) use ( &$invocations ) {
            $invocations++;
        } );
        $container->bind(IContainerContractStub::class, ContainerImplementationStub::class );

        $this->assertEquals( 0, $invocations );
        $container->make( IContainerContractStub::class );
        $this->assertEquals( 1, $invocations );
    }

[tomlankhorst]

"... these days..."
#23701

[taylorotwell]

Fixed in 5.8.

[hkodavid]

The bug is still in 5.8.12