[backport] Swap assertIdentical arguments in preparation to replace with assertSame

Thanks for looking into this @longwave.

The situation is a bit grim here. In HEAD right now part of the assertIdentical calls DO abide to its signature, but a lot of them (most?) are actually already set to ($expected, $actual,...) as it should be for assertSame.

So, I used the script below to swap all instances, and later I only git added those that require swapping. Manually.

In other words - in this issue we are just swapping those cases where the swap is needed, NOT ALL the instances.

use PhpParser\Error;
use PhpParser\ParserFactory;
use PhpParser\PrettyPrinter\Standard;
use Symfony\Component\Filesystem\Filesystem;
use Symfony\Component\Finder\Finder;

function convertMatch($parser, $printer, $part) {
  try {
    $ast = $parser->parse('<?php ' . $part);
  }
  catch (Error $error) {
    throw new \RuntimeException("Parse error: {$error->getMessage()}");
  }
  $conv = $ast[0]->expr;
//  $conv->name->name = 'assertSame';
  $tmp = clone $conv->args[1];
  $conv->args[1] = $conv->args[0];
  $conv->args[0] = $tmp;

  return [
    $printer->prettyPrintExpr($conv) . ";",
  ];
}

// Initialize the autoloader.
require_once 'autoload.php';

$parser = (new ParserFactory)->create(ParserFactory::PREFER_PHP7);
$prettyPrinter = new Standard;

$fs = new Filesystem();
$finder = new Finder();
$finder->files()->in('core/tests')->in('core/modules')->name('*.php');

foreach ($finder as $file) {

  $str = file_get_contents((string) $file);

  // Find all the instances of '$this->assertIdentical(' in the file.
  preg_match_all('/^(.*)(\$this->assertIdentical\()/m', $str, $matches, PREG_OFFSET_CAPTURE);

  if ($matches && $matches[2]) {
    echo 'Processing ' . $file . '... ' . "\n";

    // Process and convert each instance.
    $convs = []; $i = 0;
    foreach ($matches[2] as $m) {
      $start_pos = $m[1];
      $end_pos = strpos($str, ");\n", $start_pos) + 3;
      $part = substr($str, $start_pos, $end_pos - $start_pos);
      $conv = convertMatch($parser, $prettyPrinter, $part);
//dump($conv);die;
      $convs[] = [
        'start' => $start_pos,
        'end' => $end_pos,
        'prefix' => $matches[1][$i][0],
        'conv' => $conv,
      ];
      $i++;
    }
    dump($convs);

    // Recombine the file and output.
    $out = ''; $offset = 0;
    foreach ($convs as $conv) {
      $out .= substr($str, $offset, $conv['start'] - $offset);
      $out .= $conv['conv'][0] . "\n";
      $offset = $conv['end'];
    }
    $out .= substr($str, $offset);
//    dump($out);
    file_put_contents((string) $file, $out);

  }

}

OK so let's pull out the conversions to assertNull to a separate issue.

Opened #3192553: Convert assertIdentical(NULL..) to assertNull(...)

Unpostponing, related issue was committed. Rerolled.

Rerolled.

Let's reroll #3192427: [backport] Replace usages of deprecated AssertLegacyTrait::assertNotEqual first, to keep the sequence with what went in 9.2.x

Rerolled for 9.1.x

Reroll of #24.