require-extends implications on the interface

[staabm]

recently I worked on adding psalm-require-extends semantics into phpstan.

in phpstan we allowed to access public properties and public methods on the interface type as an implication of using psalm-require-extends. It seems this is something missing in psalm

this issue is meant to discuss whether we could achieve feature parity in this regard.

see https://psalm.dev/r/8aefff36a3 vs https://phpstan.org/r/707a92dc-d8e7-4749-9eb4-06f796e5e432

you might be interessted more test-cases which have been added in the following PRs:

• Implement RequireExtendsPropertiesClassReflectionExtension phpstan/phpstan-src#2856
• Implement require-extends rules phpstan/phpstan-src#2859
• require-extends should not error on interfaces phpstan/phpstan-src#2861
• phpstan/phpstan-src@9ac6fd1

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/8aefff36a3

<?php

namespace Bug10302InterfaceExtends;

use function PHPStan\Testing\assertType;

/**
 * @psalm-require-extends SomeClass
 */
interface SampleInterface
{
}

class SomeClass {
	public int $x;
	protected string $y;
	private array $z = [];

	public function doFoo():int
	{
		return 1;
	}
}

function test(SampleInterface $test): void
{
	$test->x;
	$test->y;
	$test->z;

	$test->doFoo();
}

function testExtendedInterface(AnotherInterface $test): void
{
	$test->x;
	$test->y;
	$test->z;

	$test->doFoo();
}

interface AnotherInterface extends SampleInterface
{
}

class SomeSubClass extends SomeClass {}

class ValidClass extends SomeClass implements SampleInterface {}

class ValidSubClass extends SomeSubClass implements SampleInterface {}

class InvalidClass implements SampleInterface {}

Psalm output (using commit a75d26a):

ERROR: NoInterfaceProperties - 27:2 - Interfaces cannot have properties

ERROR: NoInterfaceProperties - 28:2 - Interfaces cannot have properties

ERROR: NoInterfaceProperties - 29:2 - Interfaces cannot have properties

ERROR: UndefinedInterfaceMethod - 31:9 - Method Bug10302InterfaceExtends\SampleInterface::doFoo does not exist

ERROR: NoInterfaceProperties - 36:2 - Interfaces cannot have properties

ERROR: NoInterfaceProperties - 37:2 - Interfaces cannot have properties

ERROR: NoInterfaceProperties - 38:2 - Interfaces cannot have properties

ERROR: UndefinedInterfaceMethod - 40:9 - Method Bug10302InterfaceExtends\AnotherInterface::doFoo does not exist

ERROR: MissingConstructor - 15:13 - Bug10302InterfaceExtends\SomeClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$x, but no constructor

ERROR: MissingConstructor - 16:19 - Bug10302InterfaceExtends\SomeClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$y, but no constructor

ERROR: MissingConstructor - 15:13 - Bug10302InterfaceExtends\SomeSubClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$x, but no constructor

ERROR: MissingConstructor - 16:19 - Bug10302InterfaceExtends\SomeSubClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$y, but no constructor

ERROR: MissingConstructor - 15:13 - Bug10302InterfaceExtends\ValidClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$x, but no constructor

ERROR: MissingConstructor - 16:19 - Bug10302InterfaceExtends\ValidClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$y, but no constructor

ERROR: MissingConstructor - 15:13 - Bug10302InterfaceExtends\ValidSubClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$x, but no constructor

ERROR: MissingConstructor - 16:19 - Bug10302InterfaceExtends\ValidSubClass has an uninitialized property Bug10302InterfaceExtends\SomeClass::$y, but no constructor