Support for property fetch in initializers

Author: ondrejmirtes

src/Reflection/InitializerExprTypeResolver.php

@@ -7,6 +7,7 @@
 use PhpParser\Node\Expr\BinaryOp;
 use PhpParser\Node\Expr\ClassConstFetch;
 use PhpParser\Node\Expr\ConstFetch;
+use PhpParser\Node\Expr\PropertyFetch;
 use PhpParser\Node\Identifier;
 use PhpParser\Node\Name;
 use PhpParser\Node\Scalar\DNumber;
@@ -17,6 +18,7 @@
 use PhpParser\Node\Scalar\MagicConst\Line;
 use PhpParser\Node\Scalar\String_;
 use PHPStan\Analyser\ConstantResolver;
+use PHPStan\Analyser\OutOfClassScope;
 use PHPStan\DependencyInjection\Type\OperatorTypeSpecifyingExtensionRegistryProvider;
 use PHPStan\Node\Expr\TypeExpr;
 use PHPStan\Php\PhpVersion;
@@ -377,6 +379,15 @@ public function getType(Expr $expr, InitializerExprContext $context): Type
 			return new ConstantStringType($context->getTraitName(), true);
 		}
 
+		if ($expr instanceof PropertyFetch && $expr->name instanceof Identifier) {
+			$fetchedOnType = $this->getType($expr->var, $context);
+			if (!$fetchedOnType->hasProperty($expr->name->name)->yes()) {
+				return new ErrorType();
+			}
+
+			return $fetchedOnType->getProperty($expr->name->name, new OutOfClassScope())->getReadableType();
+		}
+
 		return new MixedType();
 	}
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1202,6 +1202,11 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7607.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/ibm_db2.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/benevolent-union-math.php');
+
+		if (PHP_VERSION_ID >= 80200) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Constants/data/bug-8957.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8956.php');
 	}
 

tests/PHPStan/Rules/Constants/MissingClassConstantTypehintRuleTest.php

@@ -5,6 +5,7 @@
 use PHPStan\Rules\MissingTypehintCheck;
 use PHPStan\Rules\Rule;
 use PHPStan\Testing\RuleTestCase;
+use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<MissingClassConstantTypehintRule>
@@ -37,4 +38,12 @@ public function testRule(): void
 		]);
 	}
 
+	public function testBug8957(): void
+	{
+		if (PHP_VERSION_ID < 80200) {
+			$this->markTestSkipped('This test needs PHP 8.2');
+		}
+		$this->analyse([__DIR__ . '/data/bug-8957.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Constants/data/bug-8957.php

@@ -0,0 +1,23 @@
+<?php // lint >= 8.2
+
+namespace Bug8957;
+
+use function PHPStan\Testing\assertType;
+
+enum A: string
+{
+	case X = 'x';
+	case Y = 'y';
+}
+
+class B {
+	public const A = [
+		A::X->value,
+		A::Y->value,
+	];
+
+	public function doFoo(): void
+	{
+		assertType('array{\'x\', \'y\'}', self::A);
+	}
+}