Inherit PHPDoc implicitly from abstract trait method

Author: ondrejmirtes

src/PhpDoc/PhpDocBlock.php

@@ -16,6 +16,7 @@
 use PHPStan\Type\TypeTraverser;
 use function array_key_exists;
 use function count;
+use function is_bool;
 use function strtolower;
 use function substr;
 
@@ -200,8 +201,26 @@ public static function resolvePhpDocBlockForMethod(
 		array $newPositionalParameterNames,
 	): self
 	{
+		$parentReflections = self::getParentReflections($classReflection);
+		foreach ($classReflection->getTraits(true) as $traitReflection) {
+			if (!$traitReflection->hasNativeMethod($methodName)) {
+				continue;
+			}
+			$traitMethod = $traitReflection->getNativeMethod($methodName);
+			$abstract = $traitMethod->isAbstract();
+			if (is_bool($abstract)) {
+				if (!$abstract) {
+					continue;
+				}
+			} elseif (!$abstract->yes()) {
+				continue;
+			}
+
+			$parentReflections[] = $traitReflection;
+		}
+
 		$docBlocksFromParents = self::resolveParentPhpDocBlocks(
-			self::getParentReflections($classReflection),
+			$parentReflections,
 			$methodName,
 			'hasNativeMethod',
 			'getNativeMethod',

tests/PHPStan/Analyser/nsrt/inherit-abstract-trait-method-phpdoc.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace InheritAbstractTraitMethodPhpDoc;
+
+use function PHPStan\Testing\assertType;
+
+trait FooTrait
+{
+
+	/** @return int */
+	abstract public function doFoo();
+
+	/** @return int */
+	public function doBar()
+	{
+		return 1;
+	}
+
+}
+
+class Foo
+{
+
+	use FooTrait;
+
+	public function doFoo()
+	{
+		return 1;
+	}
+
+	public function doBar()
+	{
+		return 1;
+	}
+
+}
+
+function (Foo $foo): void {
+	assertType('int', $foo->doFoo());
+	assertType('mixed', $foo->doBar());
+};