Allow conditional type in callable return type

Author: rvanvelzen

src/Parser/TypeParser.php

@@ -524,7 +524,7 @@ private function parseCallableReturnType(TokenIterator $tokens): Ast\Type\TypeNo
 			return $this->parseNullable($tokens);
 
 		} elseif ($tokens->tryConsumeTokenType(Lexer::TOKEN_OPEN_PARENTHESES)) {
-			$type = $this->parse($tokens);
+			$type = $this->subParse($tokens);
 			$tokens->consumeTokenType(Lexer::TOKEN_CLOSE_PARENTHESES);
 			if ($tokens->isCurrentTokenType(Lexer::TOKEN_OPEN_SQUARE_BRACKET)) {
 				$type = $this->tryParseArrayOrOffsetAccess($tokens, $type);

tests/PHPStan/Parser/TypeParserTest.php

@@ -2154,6 +2154,18 @@ public function provideParseData(): array
 					]),
 				]),
 			],
+			[
+				'Closure(Container):($serviceId is class-string<TService> ? TService : mixed)',
+				new CallableTypeNode(new IdentifierTypeNode('Closure'), [
+					new CallableTypeParameterNode(new IdentifierTypeNode('Container'), false, false, '', false),
+				], new ConditionalTypeForParameterNode(
+					'$serviceId',
+					new GenericTypeNode(new IdentifierTypeNode('class-string'), [new IdentifierTypeNode('TService')], ['invariant']),
+					new IdentifierTypeNode('TService'),
+					new IdentifierTypeNode('mixed'),
+					false
+				)),
+			],
 		];
 	}