Issue #3153567 by geek-merlin, ankithashetty, smustgrave, rkoller: Wrap...

        array_shift($backtrace);

        // Generate a backtrace containing only scalar argument values.

        $error['@backtrace'] = Error::formatBacktrace($backtrace);

        $message = new FormattableMarkup(Error::DEFAULT_ERROR_MESSAGE . ' <pre class="backtrace">@backtrace</pre>', $error);

        $message = new FormattableMarkup('<details class="error-with-backtrace"><summary>' . Error::DEFAULT_ERROR_MESSAGE . '</summary><pre class="backtrace">@backtrace</pre></details>', $error);

      }

    }

  /**

   * Tests that fatal errors return a non-zero exit code.

   *

   * @dataProvider provideFatalExitCodeData

   */

  public function testFatalExitCode() {

    $script = <<<'EOT'

<?php

  public function testFatalExitCode(string $script, string $output, string $errorOutput, bool $processIsSuccessful) {

    // We need to override the current working directory for invocations from

    // run-tests.sh to work properly.

    $process = new PhpProcess($script, $this->root);

    $process->run();

    // Assert the output strings as unrelated errors (like the log-exit.php

    // script throwing a PHP error) would still pass the final assertion.

    $this->assertEquals($output, $process->getOutput());

    $this->assertEquals($errorOutput, $process->getErrorOutput());

    $this->assertSame($processIsSuccessful, $process->isSuccessful());

  }

  public function provideFatalExitCodeData() {

    $verbose = "\$GLOBALS['config']['system.logging']['error_level'] = 'verbose';";

    $scriptBody = $this->getScriptBody();

    $data['normal'] = [

      "<?php\n\$fatal = TRUE;\n$scriptBody",

      "kernel test: This is a test message in test_function (line 456 of test.module).\n",

      "kernel test: This is a test message in test.module on line 456 backtrace\nand-more-backtrace\n",

      FALSE,

    ];

    $data['verbose'] = [

      "<?php\n\$fatal = FALSE;\n$verbose\n$scriptBody",

      "<details class=\"error-with-backtrace\"><summary><em class=\"placeholder\">kernel test</em>: This is a test message in <em class=\"placeholder\">test_function</em> (line <em class=\"placeholder\">456</em> of <em class=\"placeholder\">test.module</em>).</summary><pre class=\"backtrace\"></pre></details>",

      "",

      TRUE,

    ];

    return $data;

  }

  protected function getScriptBody() {

    return <<<'EOT'

if (PHP_SAPI !== 'cli') {

  return;

}

  '%function' => 'test_function',

  '%file' => 'test.module',

  '%line' => 456,

  '@backtrace_string' => 'backtrace',

  '@backtrace_string' => "backtrace\nand-more-backtrace",

  'severity_level' => 0,

  'backtrace' => [],

  'exception' => NULL,

];

_drupal_log_error($error, TRUE);

_drupal_log_error($error, $fatal);

EOT;

    // We need to override the current working directory for invocations from

    // run-tests.sh to work properly.

    $process = new PhpProcess($script, $this->root);

    $process->run();

    // Assert the output strings as unrelated errors (like the log-exit.php

    // script throwing a PHP error) would still pass the final assertion.

    $this->assertEquals("kernel test: This is a test message in test_function (line 456 of test.module).\n", $process->getOutput());

    $this->assertEquals("kernel test: This is a test message in test.module on line 456 backtrace\n", $process->getErrorOutput());

    $this->assertFalse($process->isSuccessful());

  }

}