revert return_type test and add specific return_self test

fixtures/completion/static_method_return_self.php

@@ -0,0 +1,12 @@
+<?php
+
+class FooClass {
+    public static function staticFoo(): self {
+        return new FooClass();
+    }
+
+    public function bar() { }
+}
+
+$foo = FooClass::staticFoo();
+$foo->

fixtures/completion/static_method_return_type.php

@@ -1,7 +1,7 @@
 <?php
 
 class FooClass {
-    public static function staticFoo(): self {
+    public static function staticFoo(): FooClass {
         return new FooClass();
     }
 

tests/Server/TextDocument/CompletionTest.php

@@ -620,6 +620,28 @@ class CompletionTest extends TestCase
         ], true), $items);
     }
 
+    public function testStaticMethodReturnSelf()
+    {
+        $completionUri = pathToUri(__DIR__ . '/../../../fixtures/completion/static_method_return_self.php');
+        $this->loader->open($completionUri, file_get_contents($completionUri));
+        $items = $this->textDocument->completion(
+            new TextDocumentIdentifier($completionUri),
+            new Position(11, 6)
+        )->wait();
+        $this->assertCompletionsListSubset(new CompletionList([
+            new CompletionItem(
+                'bar',
+                CompletionItemKind::METHOD,
+                'mixed',
+                null,
+                null,
+                null,
+                null,
+                null
+            )
+        ], true), $items);
+    }
+
     private function assertCompletionsListSubset(CompletionList $subsetList, CompletionList $list)
     {
         foreach ($subsetList->items as $expectedItem) {

tests/Validation/cases/WithReturnTypehints.php.expected.json

@@ -69,7 +69,7 @@
                 },
                 "containerName": "Fixtures\\Prophecy\\WithReturnTypehints"
             },
-            "type__tostring": "\\self",
+            "type__tostring": "\\Fixtures\\Prophecy\\WithReturnTypehints",
             "type": {},
             "declarationLine": "public function getSelf(): self {",
             "documentation": null