Assert that the value is an array before accessing its elements

tests/Functional/DataAccessTest.php

@@ -343,6 +343,7 @@ class DataAccessTest extends FunctionalTestCase
         $sql = 'SELECT test_int, test_string FROM fetch_table WHERE test_int = ? AND test_string = ?';
         $row = $this->connection->fetchArray($sql, [1, 'foo']);
 
+        self::assertIsArray($row);
         self::assertEquals(1, $row[0]);
         self::assertEquals('foo', $row[1]);
     }

tests/Functional/Schema/MySqlSchemaManagerTest.php

@@ -472,6 +472,7 @@ class MySqlSchemaManagerTest extends SchemaManagerFunctionalTestCase
             'SELECT *, DATEDIFF(CURRENT_TIMESTAMP(), col_datetime) as diff_seconds FROM test_column_defaults_are_valid'
         );
 
+        self::assertIsArray($row);
         self::assertInstanceOf(DateTime::class, DateTime::createFromFormat('Y-m-d H:i:s', $row['col_datetime']));
         self::assertNull($row['col_datetime_null']);
         self::assertSame('2012-12-12', $row['col_date']);

tests/Functional/Ticket/DBAL630Test.php

@@ -58,6 +58,7 @@ class DBAL630Test extends FunctionalTestCase
 
         $row = $this->connection->fetchAssoc('SELECT bool_col FROM dbal630 WHERE id = ?', [$id]);
 
+        self::assertIsArray($row);
         self::assertFalse($row['bool_col']);
     }
 
@@ -73,6 +74,7 @@ class DBAL630Test extends FunctionalTestCase
 
         $row = $this->connection->fetchAssoc('SELECT bool_col FROM dbal630 WHERE id = ?', [$id]);
 
+        self::assertIsArray($row);
         self::assertFalse($row['bool_col']);
     }
 
@@ -93,6 +95,7 @@ class DBAL630Test extends FunctionalTestCase
 
         $row = $this->connection->fetchAssoc('SELECT bool_col FROM dbal630 WHERE id = ?', [$id]);
 
+        self::assertIsArray($row);
         self::assertFalse($row['bool_col']);
     }
 
@@ -118,6 +121,7 @@ class DBAL630Test extends FunctionalTestCase
 
         $row = $this->connection->fetchAssoc('SELECT bool_col FROM dbal630_allow_nulls WHERE id = ?', [$id]);
 
+        self::assertIsArray($row);
         self::assertSame($databaseConvertedValue, $row['bool_col']);
     }
 
@@ -147,6 +151,7 @@ class DBAL630Test extends FunctionalTestCase
 
         $row = $this->connection->fetchAssoc('SELECT bool_col FROM dbal630_allow_nulls WHERE id = ?', [$id]);
 
+        self::assertIsArray($row);
         self::assertSame($databaseConvertedValue, $row['bool_col']);
     }