public function testWriteStderr() { $writeCalls = []; $this->mockFunction('fwrite', function ($handle, $string, $length = null) use(&$writeCalls) { $writeCalls[] = func_get_args(); return true; }); $appender = new AppenderStd(); $appender->setStream('STDERR'); $appender->write(Logger::INFO, 'test'); $this->assertSame([[STDERR, 'test']], $writeCalls); }