[PP-1] Consistent use of leading \ for class names in comments

Let's check if there are other missing slashes in type comments?

Updating issue title and summary to better reflect what the patch does

Everything seems fine for the component responsive_image.module. I apply it on 8.5.x-dev.

I just found a "typo" on the DockBlock of shortcut_set_assign_user in core/modules/shortcut/shortcut.module. The parameter & type/class were inverted.

I think we can also fix this into this patch.

Also, to go further, I try to found every other // Drupal\ or * Drupal\ in the core and found plenty others (63 results), should we have to fix them in this issue or another one with a more general context should be created ?

Together with Nevena Kostova we've found a bit more broken paths in doc blocks through the following reg-ex search (400+), during the code sprints in Vienna 2017.

(?<!types = \{)(?<!id = )(?<!type = )(?<!class: )(?<!deriver: )(?<!_form: )(?<!['"_:])(?<!namespace )(?<!use )(?<!\\)Drupal\\

Note that it is not filtering out the findings in strings in php code for some reason (there are some false-positives in the search results), but this are easy to ignore when checked manually and they are like 20-30% of the results count.

The regex was run in NetBeans reg-ex search (case insensitive way) for the whole Drupal core code-base.

Hey @angel.h thanks for the great effort on fixing all the things.
The patch is HUGE (~200KB) :D.

Here are some small things that popped during the review.

1. +++ b/core/lib/Drupal/Core/Form/FormErrorHandler.php
   @@ -72,14 +72,14 @@ protected function displayErrorMessages(array $form, FormStateInterface $form_st
       * @code
       * // The street textfield element.
       * $element = [
   -   *   '#errors' => {Drupal\Core\StringTranslation\TranslatableMarkup},
   +   *   '#errors' => {\Drupal\Core\StringTranslation\TranslatableMarkup},
       *   '#children_errors' => [],
       * ];
       * // The address detail element.
       * $element = [
       *   '#errors' => null,
       *   '#children_errors' => [
   -   *      'street' => {Drupal\Core\StringTranslation\TranslatableMarkup}
   +   *      'street' => {\Drupal\Core\StringTranslation\TranslatableMarkup}
       *   ],
       * ];
   

   This is a code example, making it close to a code change, as it's likely that people will copy-paste that.
   It might be one of the false-positives from the search...

2. +++ b/core/modules/system/src/Tests/System/HtaccessTest.php
   @@ -65,7 +65,7 @@ protected function getProtectedFiles() {
        // Tests the .htaccess file in vendor and created by a Composer script.
        // Try and access a non PHP file in the vendor directory.
   -    // @see Drupal\\Core\\Composer\\Composer::ensureHtaccess
   +    // @see \Drupal\\Core\\Composer\\Composer::ensureHtaccess
        $file_paths['vendor/composer/installed.json'] = 403;
   

   Are this double slashes correct overall?

3. +++ b/core/modules/views/tests/src/Functional/Wizard/PagerTest.php
   @@ -26,7 +26,7 @@ public function testPager() {
        // This technique for finding the existence of a pager
   -    // matches that used in Drupal\views_ui\Tests\PreviewTest.php.
   +    // matches that used in \Drupal\views_ui\Tests\PreviewTest.php.
        $elements = $this->xpath('//ul[contains(@class, :class)]/li', [':class' => 'pager__items']);
        $this->assertTrue(!empty($elements), 'Full pager found.');
   

   This is a file path, so either revert back or check that it's a class and drop the .php extension it ends with.

Re-rolled for 8.6.x (commit 7c1de1efa1) & apply suggestions of #10

It fails because of deprecation usage, what should we do ?

During my previous re-roll in #13, I made a mistake during renaming with Drupal\Tests -> DrupalTests my bad.
I also found couple of missing \Drupal.

Checkout the interdiff for more infos.

The contents of the patch does not match the issue description.

This was improperly under the responsive_image queue. It also may be a duplicate of an existing issue, but I couldn't find one.

The patch is failing the testbot and properly needs a reroll for 9.1.

Rerolled patch for 9.1

@atul4drupal I was working on it. Fixing failed test case

Regarding #30: Thanks for working on this.

Its a long file to review, here are few findings:

1) #10.2 is still not addressed

2) +++ b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php

- $this->assertStringContainsString('The class Drupal\Tests\Scripts\TestSiteApplicationTest contained in', $process->getErrorOutput());
+ $this->assertStringContainsString('The class \Drupal\Tests\Scripts\TestSiteApplicationTest contained in', $process->getErrorOutput());

this appears to be a scope creep and unnecessary change.

Fixing suggestions in 10.2

#33 thanks for the patch.
Adding the interdiff to help trace the differrence/change from #30, you mistakenly seems to have added a blank interdiff.

#33 : looks good for the fix however 31.2 is more of a code change and got introduced since #13, this certainly is not in scope of this and must be left unchanged unless we have a PHPCS rule in place for usage of \Drupal

There are several open/postponed issues with respect to inconsistent usage of '\' across the application, for reference adding https://www.drupal.org/project/drupal/issues/3123593#comment-13531928
https://www.drupal.org/project/drupal/issues/3082854#comment-13658012

Updating the patch based on #31.2.

#38 looks good and addresses the issue.
Its RTBC +1

Will wait for clarity on the PHPCS rule for "\Drupal" as also mentioned in #35, before moving this ticket any further.

Changed the parent to a Meta covering all issues about the leading \ in class names.

As, atul4drupal points out this is postponed on the sniff.