Anonymous function should have native return typehint

src/DBALException.php

@@ -180,7 +180,7 @@ class DBALException extends Exception
      */
     private static function formatParameters(array $params)
     {
-        return '[' . implode(', ', array_map(static function ($param) {
+        return '[' . implode(', ', array_map(static function ($param) : string {
             if (is_resource($param)) {
                 return (string) $param;
             }

src/Driver/Mysqli/MysqliConnection.php

@@ -63,8 +63,10 @@ class MysqliConnection implements PingableConnection, ServerInfoAwareConnection
         $this->setSecureConnection($params);
         $this->setDriverOptions($driverOptions);
 
-        set_error_handler(static function () {
+        set_error_handler(static function () : bool {
+            return true;
         });
+
         try {
             if (! $this->conn->real_connect($host, $username, $password, $dbname, $port, $socket, $flags)) {
                 throw new MysqliException($this->conn->connect_error, $this->conn->sqlstate ?? 'HY000', $this->conn->connect_errno);

src/Driver/SQLAnywhere/Driver.php

@@ -79,7 +79,7 @@ class Driver extends AbstractSQLAnywhereDriver
             ';PWD=' . $password .
             ';' . implode(
                 ';',
-                array_map(static function ($key, $value) {
+                array_map(static function ($key, $value) : string {
                     return $key . '=' . $value;
                 }, array_keys($driverOptions), $driverOptions)
             );

src/Platforms/PostgreSQL94Platform.php

@@ -905,7 +905,7 @@ SQL
 
         return $this->doConvertBooleans(
             $item,
-            static function ($boolean) {
+            static function ($boolean) : ?int {
                 return $boolean === null ? null : (int) $boolean;
             }
         );

src/Schema/AbstractAsset.php

@@ -201,7 +201,7 @@ abstract class AbstractAsset
      */
     protected function _generateIdentifierName($columnNames, $prefix = '', $maxSize = 30)
     {
-        $hash = implode('', array_map(static function ($column) {
+        $hash = implode('', array_map(static function ($column) : string {
             return dechex(crc32($column));
         }, $columnNames));
 

src/Schema/PostgreSqlSchemaManager.php

@@ -93,7 +93,7 @@ class PostgreSqlSchemaManager extends AbstractSchemaManager
         $names = $this->getSchemaNames();
         $paths = $this->getSchemaSearchPaths();
 
-        $this->existingSchemaPaths = array_filter($paths, static function ($v) use ($names) {
+        $this->existingSchemaPaths = array_filter($paths, static function ($v) use ($names) : bool {
             return in_array($v, $names, true);
         });
     }

src/Schema/Table.php

@@ -637,7 +637,7 @@ class Table extends AbstractAsset
      */
     private function filterColumns(array $columnNames)
     {
-        return array_filter($this->_columns, static function ($columnName) use ($columnNames) {
+        return array_filter($this->_columns, static function ($columnName) use ($columnNames) : bool {
             return in_array($columnName, $columnNames, true);
         }, ARRAY_FILTER_USE_KEY);
     }

tests/Functional/ConnectionTest.php

@@ -283,7 +283,7 @@ class ConnectionTest extends FunctionalTestCase
 
     public function testTransactionalReturnValue() : void
     {
-        $res = $this->connection->transactional(static function () {
+        $res = $this->connection->transactional(static function () : int {
             return 42;
         });
 

tests/Functional/DataAccessTest.php

@@ -737,7 +737,7 @@ class DataAccessTest extends FunctionalTestCase
         $stmt->setFetchMode(FetchMode::NUMERIC);
 
         $row = array_keys($stmt->fetch());
-        self::assertCount(0, array_filter($row, static function ($v) {
+        self::assertCount(0, array_filter($row, static function ($v) : bool {
             return ! is_numeric($v);
         }), 'should be no non-numerical elements in the result.');
     }

tests/Functional/StatementTest.php

@@ -303,7 +303,7 @@ EOF
                 false,
             ],
             'fetch-all' => [
-                static function (Statement $stmt) {
+                static function (Statement $stmt) : array {
                     return $stmt->fetchAll();
                 },
                 [],

tests/Functional/WriteTest.php

@@ -169,7 +169,7 @@ class WriteTest extends FunctionalTestCase
         }
 
         $sequences = $this->connection->getSchemaManager()->listSequences();
-        self::assertCount(1, array_filter($sequences, static function ($sequence) {
+        self::assertCount(1, array_filter($sequences, static function ($sequence) : bool {
             return strtolower($sequence->getName()) === 'write_table_id_seq';
         }));
 

tests/FunctionalTestCase.php

@@ -72,7 +72,7 @@ abstract class FunctionalTestCase extends TestCase
             $queries = '';
             $i       = count($this->sqlLoggerStack->queries);
             foreach (array_reverse($this->sqlLoggerStack->queries) as $query) {
-                $params   = array_map(static function ($p) {
+                $params   = array_map(static function ($p) : string {
                     if (is_object($p)) {
                         return get_class($p);
                     }

tests/Schema/DB2SchemaManagerTest.php

@@ -92,7 +92,7 @@ final class DB2SchemaManagerTest extends TestCase
     public function testListTableNamesFiltersAssetNamesCorrectlyWithCallable() : void
     {
         $accepted = ['T_FOO', 'T_BAR'];
-        $this->conn->getConfiguration()->setSchemaAssetsFilter(static function ($assetName) use ($accepted) {
+        $this->conn->getConfiguration()->setSchemaAssetsFilter(static function ($assetName) use ($accepted) : bool {
             return in_array($assetName, $accepted, true);
         });
         $this->conn->expects(self::any())->method('quote');