Implement this-out/self-out syntax

Author: rvanvelzen

Diff for: src/Ast/PhpDoc/PhpDocNode.php

@@ -328,6 +328,19 @@ static function (PhpDocTagValueNode $value): bool {
 	}
 
 
+	/**
+	 * @return SelfOutTagValueNode[]
+	 */
+	public function getSelfOutTypeTagValues(string $tagName = '@phpstan-this-out'): array
+	{
+		return array_filter(
+			array_column($this->getTagsByName($tagName), 'value'),
+			static function (PhpDocTagValueNode $value): bool {
+				return $value instanceof SelfOutTagValueNode;
+			}
+		);
+	}
+
 	public function __toString(): string
 	{
 		$children = array_map(

Diff for: src/Ast/PhpDoc/SelfOutTagValueNode.php

@@ -0,0 +1,32 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\PhpDocParser\Ast\PhpDoc;
+
+use PHPStan\PhpDocParser\Ast\NodeAttributes;
+use PHPStan\PhpDocParser\Ast\Type\TypeNode;
+use function trim;
+
+class SelfOutTagValueNode implements PhpDocTagValueNode
+{
+
+	use NodeAttributes;
+
+	/** @var TypeNode */
+	public $type;
+
+	/** @var string (may be empty) */
+	public $description;
+
+	public function __construct(TypeNode $type, string $description)
+	{
+		$this->type = $type;
+		$this->description = $description;
+	}
+
+
+	public function __toString(): string
+	{
+		return trim($this->type . ' ' . $this->description);
+	}
+
+}

Diff for: src/Parser/PhpDocParser.php

@@ -222,6 +222,13 @@ public function parseTagValue(TokenIterator $tokens, string $tag): Ast\PhpDoc\Ph
 					$tagValue = $this->parseAssertTagValue($tokens);
 					break;
 
+				case '@phpstan-this-out':
+				case '@phpstan-self-out':
+				case '@psalm-this-out':
+				case '@psalm-self-out':
+					$tagValue = $this->parseSelfOutTagValue($tokens);
+					break;
+
 				default:
 					$tagValue = new Ast\PhpDoc\GenericTagValueNode($this->parseOptionalDescription($tokens));
 					break;
@@ -499,6 +506,14 @@ private function parseAssertParameter(TokenIterator $tokens): array
 		return ['parameter' => $parameter];
 	}
 
+	private function parseSelfOutTagValue(TokenIterator $tokens): Ast\PhpDoc\SelfOutTagValueNode
+	{
+		$type = $this->typeParser->parse($tokens);
+		$description = $this->parseOptionalDescription($tokens);
+
+		return new Ast\PhpDoc\SelfOutTagValueNode($type, $description);
+	}
+
 	private function parseOptionalVariableName(TokenIterator $tokens): string
 	{
 		if ($tokens->isCurrentTokenType(Lexer::TOKEN_VARIABLE)) {

Diff for: tests/PHPStan/Parser/PhpDocParserTest.php

@@ -25,6 +25,7 @@
 use PHPStan\PhpDocParser\Ast\PhpDoc\PhpDocTextNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\PropertyTagValueNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\ReturnTagValueNode;
+use PHPStan\PhpDocParser\Ast\PhpDoc\SelfOutTagValueNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\TemplateTagValueNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\ThrowsTagValueNode;
 use PHPStan\PhpDocParser\Ast\PhpDoc\TypeAliasImportTagValueNode;
@@ -90,6 +91,7 @@ protected function setUp(): void
 	 * @dataProvider provideRealWorldExampleData
 	 * @dataProvider provideDescriptionWithOrWithoutHtml
 	 * @dataProvider provideTagsWithBackslash
+	 * @dataProvider provideSelfOutTagsData
 	 */
 	public function testParse(
 		string $label,
@@ -4485,6 +4487,79 @@ public function provideTagsWithBackslash(): Iterator
 		];
 	}
 
+	public function provideSelfOutTagsData(): Iterator
+	{
+		yield [
+			'OK phpstan-self-out',
+			'/** @phpstan-self-out self<T> */',
+			new PhpDocNode([
+				new PhpDocTagNode(
+					'@phpstan-self-out',
+					new SelfOutTagValueNode(
+						new GenericTypeNode(new IdentifierTypeNode('self'), [new IdentifierTypeNode('T')]),
+						''
+					)
+				),
+			]),
+		];
+
+		yield [
+			'OK phpstan-this-out',
+			'/** @phpstan-this-out self<T> */',
+			new PhpDocNode([
+				new PhpDocTagNode(
+					'@phpstan-this-out',
+					new SelfOutTagValueNode(
+						new GenericTypeNode(new IdentifierTypeNode('self'), [new IdentifierTypeNode('T')]),
+						''
+					)
+				),
+			]),
+		];
+
+		yield [
+			'OK psalm-self-out',
+			'/** @psalm-self-out self<T> */',
+			new PhpDocNode([
+				new PhpDocTagNode(
+					'@psalm-self-out',
+					new SelfOutTagValueNode(
+						new GenericTypeNode(new IdentifierTypeNode('self'), [new IdentifierTypeNode('T')]),
+						''
+					)
+				),
+			]),
+		];
+
+		yield [
+			'OK psalm-this-out',
+			'/** @psalm-this-out self<T> */',
+			new PhpDocNode([
+				new PhpDocTagNode(
+					'@psalm-this-out',
+					new SelfOutTagValueNode(
+						new GenericTypeNode(new IdentifierTypeNode('self'), [new IdentifierTypeNode('T')]),
+						''
+					)
+				),
+			]),
+		];
+
+		yield [
+			'OK with description',
+			'/** @phpstan-self-out self<T> description */',
+			new PhpDocNode([
+				new PhpDocTagNode(
+					'@phpstan-self-out',
+					new SelfOutTagValueNode(
+						new GenericTypeNode(new IdentifierTypeNode('self'), [new IdentifierTypeNode('T')]),
+						'description'
+					)
+				),
+			]),
+		];
+	}
+
 	/**
 	 * @dataProvider dataParseTagValue
 	 * @param PhpDocNode $expectedPhpDocNode