🚀 Support self reference

fixtures/global_references.php

@@ -41,3 +41,6 @@ TestClass::$staticTestProperty[123]->testProperty;
 
 $child = new ChildClass;
 echo $child->testMethod();
+
+// resolve self expression
+Something::getInstance()->hello();

fixtures/global_symbols.php

@@ -105,3 +105,18 @@ class ChildClass extends TestClass {}
 define('TEST_DEFINE_CONSTANT', false);
 
 print TEST_DEFINE_CONSTANT ? 'true' : 'false';
+
+// resolve self type test
+class Something {
+
+    public static function getInstance(): self {
+        return new self;
+    }
+
+    /**
+     * Does nothing
+     */
+    public function hello() {
+        echo 'Hi!';
+    }
+}

src/DefinitionResolver.php

@@ -745,10 +745,20 @@ class DefinitionResolver
                 if (is_string($node->type)) {
                     // Resolve a string like "bool" to a type object
                     $type = $this->typeResolver->resolve($node->type);
-                } else {
+                } else if ($node->returnType instanceof Node\Name) {
-                    $type = new Types\Object_(new Fqsen('\\' . (string)$node->type));
+                    $type = (string)$node->returnType;
+
+                    if (strtolower($type) === 'self') {
+                        // handle self reference
+                        $class = getClosestNode($node, Node\Stmt\Class_::class);
+
+                        if($class !== null) {
+                            return new Types\Object_(new Fqsen('\\' . $class->name));
                         }
                     }
+                }
+                $type = new Types\Object_(new Fqsen('\\' . (string)$node->type));
+            }
             if ($node->default !== null) {
                 $defaultType = $this->resolveExpressionNodeToType($node->default);
                 if (isset($type) && !is_a($type, get_class($defaultType))) {
@@ -776,6 +786,18 @@ class DefinitionResolver
                     // Resolve a string like "bool" to a type object
                     return $this->typeResolver->resolve($node->returnType);
                 }
+                if ($node->returnType instanceof Node\Name) {
+                    $type = (string)$node->returnType;
+
+                    if (strtolower($type) === 'self') {
+                        // handle self reference
+                        $class = getClosestNode($node, Node\Stmt\Class_::class);
+
+                        if ($class !== null) {
+                            return new Types\Object_(new Fqsen('\\' . $class->name));
+                        }
+                    }
+                }
                 return new Types\Object_(new Fqsen('\\' . (string)$node->returnType));
             }
             // Unknown return type

tests/Server/ServerTestCase.php

@@ -85,6 +85,9 @@ abstract class ServerTestCase extends TestCase
             'TestClass::testMethod()'                => new Location($globalSymbolsUri,    new Range(new Position(57,  4), new Position(60,   5))),
             'test_function()'                        => new Location($globalSymbolsUri,    new Range(new Position(78,  0), new Position(81,   1))),
             'whatever()'                             => new Location($globalReferencesUri, new Range(new Position(21,  0), new Position(23,   1))),
+            'Something'                              => new Location($globalSymbolsUri,    new Range(new Position(109, 0), new Position(121,  1))),
+            'Something::getInstance()'               => new Location($globalSymbolsUri,    new Range(new Position(111, 4), new Position(113,  5))),
+            'Something::hello()'                     => new Location($globalSymbolsUri,    new Range(new Position(118, 4), new Position(120,  5))),
 
             // Namespaced
             'TestNamespace'                                => new Location($symbolsUri,    new Range(new Position( 2, 10), new Position( 2,  23))),
@@ -214,6 +217,15 @@ abstract class ServerTestCase extends TestCase
             'test_function()' => [
                 0 => new Location($globalReferencesUri, new Range(new Position(10,  0), new Position(10, 13))),
                 1 => new Location($globalReferencesUri, new Range(new Position(31, 13), new Position(31, 40)))
+            ],
+            'Something' => [
+                0 => new Location($globalReferencesUri, new Range(new Position(45,  0), new Position(56,  9)))  // Something::getInstance()->hello()
+            ],
+            'Something::getInstance()' => [
+                0 => new Location($globalReferencesUri, new Range(new Position(45,  0), new Position(45, 24)))  // Something::getInstance()->hello()
+            ],
+            'Something::hello()' => [
+                0 => new Location($globalReferencesUri, new Range(new Position(45,  0), new Position(45, 33)))  // Something::getInstance()->hello()
             ]
         ];
         // @codingStandardsIgnoreEnd

tests/Server/TextDocument/CompletionTest.php

@@ -179,6 +179,15 @@ class CompletionTest extends TestCase
                 null,
                 '\ChildClass'
             ),
+            new CompletionItem(
+                'Something',
+                CompletionItemKind::CLASS_,
+                null,
+                null,
+                null,
+                null,
+                '\Something'
+            ),
             // Namespaced, `use`d TestClass definition (inserted as TestClass)
             new CompletionItem(
                 'TestClass',

tests/Server/TextDocument/HoverTest.php

@@ -31,6 +31,21 @@ class HoverTest extends ServerTestCase
         ], $reference->range), $result);
     }
 
+    public function testHoverForSelfReturnTypeDefintion()
+    {
+        // class Something
+        // get hover for Something::getInstance() (returns a instance of Something)
+        $reference = $this->getReferenceLocations('Something::hello()')[0];
+        $result = $this->textDocument->hover(
+            new TextDocumentIdentifier($reference->uri),
+            $reference->range->end
+        )->wait();
+        $this->assertEquals(new Hover([
+            new MarkedString('php', "<?php\npublic function hello()"),
+            'Does nothing'
+        ], $reference->range), $result);
+    }
+
     public function testHoverForClassLikeDefinition()
     {
         // class TestClass implements TestInterface

tests/Server/Workspace/SymbolTest.php

@@ -59,6 +59,9 @@ class SymbolTest extends ServerTestCase
             new SymbolInformation('test_function',          SymbolKind::FUNCTION,    $this->getDefinitionLocation('test_function()'),                              ''),
             new SymbolInformation('ChildClass',             SymbolKind::CLASS_,      $this->getDefinitionLocation('ChildClass'),                                   ''),
             new SymbolInformation('TEST_DEFINE_CONSTANT',   SymbolKind::CONSTANT,    $this->getDefinitionLocation('TEST_DEFINE_CONSTANT'),                         ''),
+            new SymbolInformation('Something',              SymbolKind::CLASS_,      $this->getDefinitionLocation('Something'),                                    ''),
+            new SymbolInformation('getInstance',            SymbolKind::METHOD,      $this->getDefinitionLocation('Something::getInstance()'),                     'Something'),
+            new SymbolInformation('hello',                  SymbolKind::METHOD,      $this->getDefinitionLocation('Something::hello()'),                           'Something'),
             new SymbolInformation('whatever',               SymbolKind::FUNCTION,    $this->getDefinitionLocation('whatever()'),                                   ''),
 
             new SymbolInformation('SecondTestNamespace',    SymbolKind::NAMESPACE,   $this->getDefinitionLocation('SecondTestNamespace'),                          '')