Treat trait-declared properties as initialized when promoted by an inherited constructor

src/Node/ClassPropertiesNode.php

@@ -138,6 +138,10 @@ public function getUninitializedProperties(
 					continue;
 				}
 
+				if ($propertyReflection->getDeclaringClass()->getName() !== $classReflection->getName()) {
+					$is = TrinaryLogic::createYes();
+				}
+
 				foreach ($extensions as $extension) {
 					if (!$extension->isInitialized($propertyReflection, $property->getName())) {
 						continue;

tests/PHPStan/Rules/Properties/MissingReadOnlyByPhpDocPropertyAssignRuleTest.php

@@ -154,4 +154,15 @@ public function testBug13856(): void
 		$this->analyse([__DIR__ . '/data/bug-13856-phpdoc.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.0.0')]
+	public function testBug14983(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14983-phpdoc.php'], [
+			[
+				'Class Bug14983PhpDoc\UninitializedFromTrait has an uninitialized @readonly property $property. Assign it in the constructor.',
+				9,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Properties/MissingReadOnlyPropertyAssignRuleTest.php

@@ -152,6 +152,17 @@ public function testRule(): void
 		]);
 	}
 
+	#[RequiresPhp('>= 8.1.0')]
+	public function testBug14983(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14983.php'], [
+			[
+				'Class Bug14983\UninitializedFromTrait has an uninitialized readonly property $property. Assign it in the constructor.',
+				8,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.1.0')]
 	public function testBug7119(): void
 	{

tests/PHPStan/Rules/Properties/UninitializedPropertyRuleTest.php

@@ -233,4 +233,10 @@ public function testBug12547(): void
 		$this->analyse([__DIR__ . '/data/bug-12547.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.0.0')]
+	public function testBug14983(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14983-uninitialized.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/bug-14983-phpdoc.php

@@ -0,0 +1,43 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug14983PhpDoc;
+
+trait TraitA {
+	/** @readonly */
+	protected string $property;
+}
+
+trait TraitB {
+	use TraitA;
+}
+
+class ClassA {
+	use TraitA;
+
+	public function __construct(
+		/** @readonly */
+		protected string $property,
+	) {}
+}
+
+class ClassB extends ClassA {
+	use TraitB;
+}
+
+class BodyInitClassA {
+	use TraitA;
+
+	public function __construct(string $property) {
+		$this->property = $property;
+	}
+}
+
+class BodyInitClassB extends BodyInitClassA {
+	use TraitB;
+}
+
+class UninitializedFromTrait {
+	use TraitA;
+}

tests/PHPStan/Rules/Properties/data/bug-14983-uninitialized.php

@@ -0,0 +1,35 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug14983Uninitialized;
+
+trait TraitA {
+	protected string $property;
+}
+
+trait TraitB {
+	use TraitA;
+}
+
+class ClassA {
+	use TraitA;
+
+	public function __construct(protected string $property) {}
+}
+
+class ClassB extends ClassA {
+	use TraitB;
+}
+
+class BodyInitClassA {
+	use TraitA;
+
+	public function __construct(string $property) {
+		$this->property = $property;
+	}
+}
+
+class BodyInitClassB extends BodyInitClassA {
+	use TraitB;
+}

tests/PHPStan/Rules/Properties/data/bug-14983.php

@@ -0,0 +1,55 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug14983;
+
+trait TraitA {
+	protected readonly string $property;
+}
+
+trait TraitB {
+	use TraitA;
+}
+
+class ClassA {
+	use TraitA;
+
+	public function __construct(protected readonly string $property) {}
+}
+
+class ClassB extends ClassA {
+	use TraitB;
+}
+
+class BodyInitClassA {
+	use TraitA;
+
+	public function __construct(string $property) {
+		$this->property = $property;
+	}
+}
+
+class BodyInitClassB extends BodyInitClassA {
+	use TraitB;
+}
+
+trait GrandTrait {
+	use TraitA;
+}
+
+class GrandParent1 {
+	use TraitA;
+
+	public function __construct(protected readonly string $property) {}
+}
+
+class Parent1 extends GrandParent1 {}
+
+class Child1 extends Parent1 {
+	use GrandTrait;
+}
+
+class UninitializedFromTrait {
+	use GrandTrait;
+}