Avoid adding void/never return tag to generator functions (#456)

Author: IanDelMar

src/Visitor.php

@@ -15,6 +15,8 @@
 use PhpParser\Comment\Doc;
 use PhpParser\ConstExprEvaluator;
 use PhpParser\Node;
+use PhpParser\Node\Expr\Yield_;
+use PhpParser\Node\Expr\YieldFrom;
 use PhpParser\NodeFinder;
 use PhpParser\Node\Identifier;
 use PhpParser\Node\Name;
@@ -813,6 +815,18 @@ private function voidOrNever(Node $node): ?Type
             return null;
         }
 
+        $yields = $this->nodeFinder->findFirst(
+            $node,
+            static function (Node $node): bool {
+                return $node instanceof Yield_ || $node instanceof YieldFrom;
+            }
+        ) instanceof Node;
+
+        if ($yields) {
+            // Generator functions do not return void or never.
+            return null;
+        }
+
         $returnStmts = $this->nodeFinder->findInstanceOf($node, Stmt_Return::class);
 
         // If there is a return statement, it's not return type never.
@@ -852,14 +866,14 @@ static function (Node $node): bool {
             if (! ($stmt->expr instanceof FuncCall) || ! ($stmt->expr->name instanceof Name)) {
                 continue;
             }
-            $name = $stmt->expr->name;
+            $name = strtolower((string)$stmt->expr->name);
             // If a first level statement is a call to wp_send_json(_success/error),
             // it's return type never.
-            if (str_starts_with($name->toString(), 'wp_send_json')) {
+            if (str_starts_with($name, 'wp_send_json')) {
                 return $never;
             }
             // Skip all functions but wp_die().
-            if (! str_starts_with($name->toString(), 'wp_die')) {
+            if (! str_starts_with($name, 'wp_die')) {
                 continue;
             }
             $args = $stmt->expr->getArgs();

wordpress-stubs.php

@@ -68704,7 +68704,6 @@ public function paused_at_incomplete_token(): bool
          *     // Outputs: "free <egg> lang-en "
          *
          * @since 6.4.0
-         * @phpstan-return void
          */
         public function class_list()
         {