feat: improve phpstan level 9 with all errors resolved

phpstan.neon.dist

@@ -1,5 +1,5 @@
 parameters:
-    level: 8
+    level: 9
     phpVersion: 80402
     paths:
         - src

src/Cache/ArrayResult.php

@@ -107,7 +107,7 @@ public function __serialize(): array
         return [$this->columnNames, $this->rows];
     }
 
-    /** @param mixed[] $data */
+    /** @param array{0: list<string>, 1: list<list<mixed>>} $data */
     public function __unserialize(array $data): void
     {
         // Handle objects serialized with DBAL 4.1 and earlier.

src/Connection.php

@@ -40,6 +40,7 @@
 
 use function array_key_exists;
 use function array_merge;
+use function assert;
 use function count;
 use function implode;
 use function is_array;
@@ -158,7 +159,15 @@ public function getDatabase(): ?string
         $platform = $this->getDatabasePlatform();
         $query    = $platform->getDummySelectSQL($platform->getCurrentDatabaseExpression());
 
-        return $this->fetchOne($query);
+        $database = $this->fetchOne($query);
+
+        if ($database === false) {
+            return null;
+        }
+
+        assert(is_string($database) && $database !== '');
+
+        return $database;
     }
 
     /**

src/Driver/AbstractOracleDriver/EasyConnectString.php

@@ -6,8 +6,11 @@
 
 use Doctrine\Deprecations\Deprecation;
 
+use function assert;
 use function implode;
 use function is_array;
+use function is_scalar;
+use function is_string;
 use function sprintf;
 
 /**
@@ -44,11 +47,16 @@ public static function fromArray(array $params): self
     public static function fromConnectionParameters(array $params): self
     {
         if (isset($params['connectstring'])) {
+            assert(is_string($params['connectstring']));
+
             return new self($params['connectstring']);
         }
 
         if (! isset($params['host'])) {
-            return new self($params['dbname'] ?? '');
+            $dbname = $params['dbname'] ?? '';
+            assert(is_string($dbname));
+
+            return new self($dbname);
         }
 
         $connectData = [];
@@ -118,6 +126,8 @@ private static function renderValue(mixed $value): string
             return self::renderParams($value);
         }
 
+        assert(is_scalar($value));
+
         return (string) $value;
     }
 }

src/Driver/IBMDB2/DataSourceName.php

@@ -6,7 +6,10 @@
 
 use SensitiveParameter;
 
+use function assert;
 use function implode;
+use function is_scalar;
+use function is_string;
 use function sprintf;
 use function str_contains;
 
@@ -38,7 +41,8 @@ public static function fromArray(
         $chunks = [];
 
         foreach ($params as $key => $value) {
-            $chunks[] = sprintf('%s=%s', $key, $value);
+            assert(is_scalar($value)); // Since value is mixed, ensure it's scalar for string conversion
+            $chunks[] = sprintf('%s=%s', $key, (string) $value);
         }
 
         return new self(implode(';', $chunks));
@@ -52,8 +56,11 @@ public static function fromArray(
     public static function fromConnectionParameters(#[SensitiveParameter]
     array $params,): self
     {
-        if (isset($params['dbname']) && str_contains($params['dbname'], '=')) {
-            return new self($params['dbname']);
+        if (isset($params['dbname'])) {
+            assert(is_string($params['dbname'])); // Check type to help phpstan infer the type before using str_contains
+            if (str_contains($params['dbname'], '=')) {
+                return new self($params['dbname']);
+            }
         }
 
         $dsnParams = [];

src/Driver/IBMDB2/Statement.php

@@ -18,6 +18,7 @@
 use function fclose;
 use function is_int;
 use function is_resource;
+use function is_string;
 use function stream_copy_to_stream;
 use function stream_get_meta_data;
 use function tmpfile;
@@ -60,6 +61,8 @@ public function bindValue(int|string $param, mixed $value, ParameterType $type):
                 break;
 
             case ParameterType::LARGE_OBJECT:
+                // Ensure that the value is either a string, a resource, or null (the assert is needed to help to phpstan to infer the type at level 9)
+                assert(is_string($value) || is_resource($value) || $value === null);
                 $this->lobs[$param] = &$value;
                 break;
 

src/Driver/Mysqli/Driver.php

@@ -15,6 +15,12 @@
 use mysqli_sql_exception;
 use SensitiveParameter;
 
+use function assert;
+use function is_array;
+use function is_int;
+use function is_scalar;
+use function is_string;
+
 final class Driver extends AbstractMySQLDriver
 {
     /**
@@ -41,14 +47,16 @@ public function connect(
         }
 
         try {
+            $flags = $params['driverOptions'][Connection::OPTION_FLAGS] ?? 0; // Intermediate variable to help phpstan level 9 infer the type
+            assert(is_int($flags));
             $success = @$connection->real_connect(
                 $host,
                 $params['user'] ?? '',
                 $params['password'] ?? '',
                 $params['dbname'] ?? '',
                 $params['port'] ?? 0,
                 $params['unix_socket'] ?? '',
-                $params['driverOptions'][Connection::OPTION_FLAGS] ?? 0,
+                $flags,
             );
         } catch (mysqli_sql_exception $e) {
             throw ConnectionFailed::upcast($e);
@@ -74,10 +82,15 @@ private function compilePreInitializers(
         #[SensitiveParameter]
         array $params,
     ): Generator {
-        unset($params['driverOptions'][Connection::OPTION_FLAGS]);
-
-        if (isset($params['driverOptions']) && $params['driverOptions'] !== []) {
-            yield new Options($params['driverOptions']);
+        if (isset($params['driverOptions'])) {
+            assert(is_array($params['driverOptions']));
+            $driverOptions = $params['driverOptions'];
+            unset($driverOptions[Connection::OPTION_FLAGS]);
+
+            /** @var array<int, mixed> $driverOptions */
+            if ($driverOptions !== []) {
+                yield new Options($driverOptions);
+            }
         }
 
         if (
@@ -90,12 +103,43 @@ private function compilePreInitializers(
             return;
         }
 
+        // Create intermediate variables for phpstan level 9 type inference
+        $ssl_key = '';
+        if (isset($params['ssl_key'])) {
+            assert(is_scalar($params['ssl_key']));
+            $ssl_key = (string) $params['ssl_key'];
+        }
+
+        $ssl_cert = '';
+        if (isset($params['ssl_cert'])) {
+            assert(is_scalar($params['ssl_cert']));
+            $ssl_cert = (string) $params['ssl_cert'];
+        }
+
+        $ssl_ca = '';
+        if (isset($params['ssl_ca'])) {
+            assert(is_scalar($params['ssl_ca']));
+            $ssl_ca = (string) $params['ssl_ca'];
+        }
+
+        $ssl_capath = '';
+        if (isset($params['ssl_capath'])) {
+            assert(is_scalar($params['ssl_capath']));
+            $ssl_capath = (string) $params['ssl_capath'];
+        }
+
+        $ssl_cipher = '';
+        if (isset($params['ssl_cipher'])) {
+            assert(is_scalar($params['ssl_cipher']));
+            $ssl_cipher = (string) $params['ssl_cipher'];
+        }
+
         yield new Secure(
-            $params['ssl_key']    ?? '',
-            $params['ssl_cert']   ?? '',
-            $params['ssl_ca']     ?? '',
-            $params['ssl_capath'] ?? '',
-            $params['ssl_cipher'] ?? '',
+            $ssl_key,
+            $ssl_cert,
+            $ssl_ca,
+            $ssl_capath,
+            $ssl_cipher,
         );
     }
 
@@ -112,6 +156,8 @@ private function compilePostInitializers(
             return;
         }
 
+        assert(is_string($params['charset']));
+
         yield new Charset($params['charset']);
     }
 }

src/Driver/Mysqli/Exception/ConnectionError.php

@@ -9,18 +9,25 @@
 use mysqli_sql_exception;
 use ReflectionProperty;
 
+use function assert;
+use function is_string;
+
 /** @internal */
 final class ConnectionError extends AbstractException
 {
     public static function new(mysqli $connection): self
     {
-        return new self($connection->error, $connection->sqlstate, $connection->errno);
+        $sqlstate = $connection->sqlstate;
+
+        return new self($connection->error, $sqlstate, $connection->errno);
     }
 
     public static function upcast(mysqli_sql_exception $exception): self
     {
-        $p = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $p        = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $sqlstate = $p->getValue($exception);
+        assert(is_string($sqlstate)); // Intermediate variable for phpstan type inference
 
-        return new self($exception->getMessage(), $p->getValue($exception), $exception->getCode(), $exception);
+        return new self($exception->getMessage(), $sqlstate, $exception->getCode(), $exception);
     }
 }

src/Driver/Mysqli/Exception/ConnectionFailed.php

@@ -10,6 +10,7 @@
 use ReflectionProperty;
 
 use function assert;
+use function is_string;
 
 /** @internal */
 final class ConnectionFailed extends AbstractException
@@ -24,8 +25,10 @@ public static function new(mysqli $connection): self
 
     public static function upcast(mysqli_sql_exception $exception): self
     {
-        $p = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $p        = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $sqlstate = $p->getValue($exception);
+        assert(is_string($sqlstate));
 
-        return new self($exception->getMessage(), $p->getValue($exception), $exception->getCode(), $exception);
+        return new self($exception->getMessage(), $sqlstate, $exception->getCode(), $exception);
     }
 }

src/Driver/Mysqli/Exception/InvalidCharset.php

@@ -9,6 +9,8 @@
 use mysqli_sql_exception;
 use ReflectionProperty;
 
+use function assert;
+use function is_string;
 use function sprintf;
 
 /** @internal */
@@ -25,11 +27,13 @@ public static function fromCharset(mysqli $connection, string $charset): self
 
     public static function upcast(mysqli_sql_exception $exception, string $charset): self
     {
-        $p = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $p        = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $sqlstate = $p->getValue($exception);
+        assert(is_string($sqlstate));
 
         return new self(
             sprintf('Failed to set charset "%s": %s', $charset, $exception->getMessage()),
-            $p->getValue($exception),
+            $sqlstate,
             $exception->getCode(),
             $exception,
         );

src/Driver/Mysqli/Exception/InvalidOption.php

@@ -6,15 +6,20 @@
 
 use Doctrine\DBAL\Driver\AbstractException;
 
+use function gettype;
+use function is_scalar;
 use function sprintf;
+use function strval;
 
 /** @internal */
 final class InvalidOption extends AbstractException
 {
     public static function fromOption(int $option, mixed $value): self
     {
+        $stringValue = is_scalar($value) || $value === null ? strval($value) : gettype($value);
+
         return new self(
-            sprintf('Failed to set option %d with value "%s"', $option, $value),
+            sprintf('Failed to set option %d with value "%s"', $option, $stringValue),
         );
     }
 }

src/Driver/Mysqli/Exception/StatementError.php

@@ -9,18 +9,26 @@
 use mysqli_stmt;
 use ReflectionProperty;
 
+use function assert;
+use function is_string;
+
 /** @internal */
 final class StatementError extends AbstractException
 {
     public static function new(mysqli_stmt $statement): self
     {
-        return new self($statement->error, $statement->sqlstate, $statement->errno);
+        $sqlstate = $statement->sqlstate;
+        assert($sqlstate !== '');
+
+        return new self($statement->error, $sqlstate, $statement->errno);
     }
 
     public static function upcast(mysqli_sql_exception $exception): self
     {
-        $p = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $p        = new ReflectionProperty(mysqli_sql_exception::class, 'sqlstate');
+        $sqlstate = $p->getValue($exception);
+        assert(is_string($sqlstate) && $sqlstate !== '');
 
-        return new self($exception->getMessage(), $p->getValue($exception), $exception->getCode(), $exception);
+        return new self($exception->getMessage(), $sqlstate, $exception->getCode(), $exception);
     }
 }

src/Driver/Mysqli/Initializer/Options.php

@@ -8,6 +8,9 @@
 use Doctrine\DBAL\Driver\Mysqli\Initializer;
 use mysqli;
 
+use function assert;
+use function is_int;
+use function is_string;
 use function mysqli_options;
 
 final class Options implements Initializer
@@ -20,6 +23,8 @@ public function __construct(private readonly array $options)
     public function initialize(mysqli $connection): void
     {
         foreach ($this->options as $option => $value) {
+            assert(is_int($value) || is_string($value));
+            /** @var int|string $value */
             if (! mysqli_options($connection, $option, $value)) {
                 throw InvalidOption::fromOption($option, $value);
             }