Determine return value from \Drupal\Core\Config\Config::get

[mstrelan]

Feature request

\Drupal\Core\Config\Config::get returns mixed.

Given the following code in a functional test:

$theme = $this->config('system.theme')->get('default');
$this->assertStringContainsString('foo', $theme);

When I analyze it with phpstan level 9 I get:

Parameter #2 $haystack of method PHPUnit\Framework\Assert::assertStringContainsString() expects string, mixed given. 

However we have config schema for system.theme that says that default is a string. Perhaps we can figure this out in phpstan-drupal so we don't need to make assertions about the data. However it might not be wise to do this. If we put the same code in to a kernel test then $theme is in fact null, so phpstan is right to complain about it.

[mglaman]

The one hard part I foresee: I'm pretty sure the typed config manager is stateful. If it doesn't rely on the database at all and only plugin discovery maybe we can make this work

[simesy]

Why not contribute a method(s) to the class in Drupal that returns explicit types, and even throws an exception if the type is not a match? It seems like methods for scalar types like Config::getString() should be feasible? The caller is responsible for knowing what type to expect.