fix generic alias resolution: skip alias path when name resolves to a…

… known class
phpstan · shmax · Apr 1, 2026 · Apr 1, 2026 · Apr 1, 2026 · Apr 1, 2026
commit beedafbf1f2faf6c74f266bdea7c0d1fb0efbea7
diff --git a/src/PhpDoc/TypeNodeResolver.php b/src/PhpDoc/TypeNodeResolver.php
@@ -840,9 +840,15 @@ static function (string $variance): TemplateTypeVariance {
 			return new ErrorType();
 		}
 
-		// Check for a generic type alias (e.g. ProviderRequest<AppraisalFilter>) before
-		// falling through to class-based generic resolution.
-		$genericTypeAlias = $this->findGenericTypeAlias($typeNode->type->name, $nameScope);
+		// Check for a generic type alias (e.g. MyList<string>) before falling through to
+		// class-based generic resolution, but only when the name is not itself a resolvable
+		// class — in that case the class-based path must win to preserve backward compatibility
+		// (a type alias like BelongsTo<T, U> = \Eloquent\BelongsTo<T, U> should still produce
+		// the same GenericObjectType that class-based resolution would have given).
+		$resolvedGenericName = $nameScope->resolveStringName($typeNode->type->name);
+		$genericTypeAlias = !$this->getReflectionProvider()->hasClass($resolvedGenericName)
+			? $this->findGenericTypeAlias($typeNode->type->name, $nameScope)
+			: null;
 		if ($genericTypeAlias !== null) {
 			$templateNodes = $genericTypeAlias->getTemplateTagValueNodes();
 			$totalParams = count($templateNodes);