Introduce PDO::connect dynamicMethodReturnType

conf/config.neon

@@ -1585,6 +1585,11 @@ services:
 		tags:
 			- phpstan.functionParameterOutTypeExtension
 
+	-
+		class: PHPStan\Type\Php\PDOConnectReturnTypeExtension
+		tags:
+			- phpstan.broker.dynamicStaticMethodReturnTypeExtension
+
 	-
 		class: PHPStan\Type\Php\PregMatchTypeSpecifyingExtension
 		tags:

src/Php/PhpVersion.php

@@ -405,4 +405,9 @@ public function supportsBcMathNumberOperatorOverloading(): bool
 		return $this->versionId >= 80400;
 	}
 
+	public function hasPDOSubclasses(): bool
+	{
+		return $this->versionId >= 80400;
+	}
+
 }

src/Type/Php/PDOConnectReturnTypeExtension.php

@@ -0,0 +1,76 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type\Php;
+
+use PhpParser\Node\Expr\StaticCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Php\PhpVersion;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Type\DynamicStaticMethodReturnTypeExtension;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
+use function count;
+use function str_starts_with;
+
+/**
+ * @see https://wiki.php.net/rfc/pdo_driver_specific_subclasses
+ * @see https://github.com/php/php-src/pull/12804
+ */
+final class PDOConnectReturnTypeExtension implements DynamicStaticMethodReturnTypeExtension
+{
+
+	public function __construct(private PhpVersion $phpVersion)
+	{
+	}
+
+	public function getClass(): string
+	{
+		return 'PDO';
+	}
+
+	public function isStaticMethodSupported(MethodReflection $methodReflection): bool
+	{
+		return $this->phpVersion->hasPDOSubclasses() && $methodReflection->getName() === 'connect';
+	}
+
+	public function getTypeFromStaticMethodCall(MethodReflection $methodReflection, StaticCall $methodCall, Scope $scope): ?Type
+	{
+		if (count($methodCall->getArgs()) < 1) {
+			return null;
+		}
+
+		$valueType = $scope->getType($methodCall->getArgs()[0]->value);
+		$constantStrings = $valueType->getConstantStrings();
+		if (count($constantStrings) === 0) {
+			return null;
+		}
+
+		$subclasses = [];
+		foreach ($constantStrings as $constantString) {
+			if (str_starts_with($constantString->getValue(), 'mysql:')) {
+				$subclasses['PDO\Mysql'] = 'PDO\Mysql';
+			} elseif (str_starts_with($constantString->getValue(), 'firebird:')) {
+				$subclasses['PDO\Firebird'] = 'PDO\Firebird';
+			} elseif (str_starts_with($constantString->getValue(), 'dblib:')) {
+				$subclasses['PDO\Dblib'] = 'PDO\Dblib';
+			} elseif (str_starts_with($constantString->getValue(), 'odbc:')) {
+				$subclasses['PDO\Odbc'] = 'PDO\Odbc';
+			} elseif (str_starts_with($constantString->getValue(), 'pgsql:')) {
+				$subclasses['PDO\Pgsql'] = 'PDO\Pgsql';
+			} elseif (str_starts_with($constantString->getValue(), 'sqlite:')) {
+				$subclasses['PDO\Sqlite'] = 'PDO\Sqlite';
+			} else {
+				return null;
+			}
+		}
+
+		$returnTypes = [];
+		foreach ($subclasses as $class) {
+			$returnTypes[] = new ObjectType($class);
+		}
+
+		return TypeCombinator::union(...$returnTypes);
+	}
+
+}

tests/PHPStan/Analyser/nsrt/pdo-connect-php84.php

@@ -0,0 +1,26 @@
+<?php // lint >= 8.4
+
+namespace PdoConnectPHP84;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param 'mysql:foo'|'pgsql:foo' $mysqlOrPgsql
+ * @param 'mysql:foo'|'foo:foo' $mysqlOrFoo
+ */
+function test(
+	string $string,
+	string $mysqlOrPgsql,
+	string $mysqlOrFoo,
+) {
+	assertType('PDO\Mysql', \PDO::connect('mysql:foo'));
+	assertType('PDO\Firebird', \PDO::connect('firebird:foo'));
+	assertType('PDO\Dblib', \PDO::connect('dblib:foo'));
+	assertType('PDO\Odbc', \PDO::connect('odbc:foo'));
+	assertType('PDO\Pgsql', \PDO::connect('pgsql:foo'));
+	assertType('PDO\Sqlite', \PDO::connect('sqlite:foo'));
+
+	assertType('PDO', \PDO::connect($string));
+	assertType('PDO\Mysql|PDO\Pgsql', \PDO::connect($mysqlOrPgsql));
+	assertType('PDO', \PDO::connect($mysqlOrFoo));
+}