Testing the untestable: Test network kill during fetch

fetch-network-killer.php

<?php

public function testNetworkKillerFetch(): void
{
  $this->setupLargeTable();
  ErrorHandler::register(null, true);
  $stmt = $this->taintedPdo->query('SELECT * FROM largeTable LIMIT 100000');
  $stmt->execute();
  self::expectException(\ErrorException::class);
  self::expectExceptionMessage('Warning: Empty row packet body');
  $this->killerEnabled = 'fetch';
  while ($row = $stmt->fetch()) {
  }
}