Change !isset to ??= assignment operator: phpstan errors "always exists and is not nullable" case.

Variable $access_plugin on left side of ??= always exists and is not nullable.

Ignored error pattern #^Variable \$access_plugin in isset\(\) always exists and is not nullable\.$# in path

If either error is true, then the line should not be converted to ??=. Nor should it be left as isset().

If the change is correct, then the code leading to it should be changed. With better typehints, for example.

I'd suggest changing the code in the other issue. Just make sure you are justifying the change clearly in documenting a issue/MR comment.

For PathPluginBase, \Drupal\views\Plugin\views\display\DisplayPluginInterface::getPlugin the docs say it can never return null.

However I can see there a return void;, so lets create an issue just for this, which changes the documentation, and explicitly return NULL;

This issue could be used as a template: 🐛 \Drupal\Core\Config\StorageInterface::read is typehinted as possibly returning bool, but never returns true Fixed

In this case I wouldnt recommend changing the relevant lines in the ??= issue.

For PreviewTest.php, lets keep the change in the ??= issue.

However, lets change \Drupal\Tests\views_ui\FunctionalJavascript\PreviewTest::assertClass so the method signature (and docs) match \Drupal\Tests\system\Functional\Pager\PagerTest::assertClass.

@dpi, thank you for your answer, We can discuss.

For PreviewTest.php, lets keep the change in the ??= issue.

Well, this case block the MR, because of the phpstan error. I face this before.

For PathPluginBase, \Drupal\views\Plugin\views\display\DisplayPluginInterface::getPlugin the docs say it can never return null.

So, is not nullable, so,

    if (!isset($access_plugin)) {
      // @todo Do we want to support a default plugin in getPlugin itself?
      $access_plugin = Views::pluginManager('access')->createInstance('none');
    }

is inconsistent: never go in the block. Or is nullable, and this code is okay (...and could be changed to ??=).

@dpi, I think the problem is not ??=. The problem, as phpstan tells us, is not nullable + isset.

I push the work, since done. It can be refused.

May be refused, but nice information: with these few changes now these two cases have MR mergeable. A step forward.

Okay @dpi, after having a look your requests about null are clear for me.

About #6 📌 Use null coalescing assignment operator ??=: phpstan obstruction case. Closed: won't fix , on one side, in core/modules/views_ui/tests/src/FunctionalJavascript/PreviewTest.php,

  /**
   * Asserts that an element has a given class.
   *
   * @param \Behat\Mink\Element\NodeElement $element
   *   The element to test.
   * @param string $class
   *   The class to assert.
   * @param string $message
   *   (optional) A verbose message to output.
   *
   * @internal
   */
  protected function assertClass(NodeElement $element, string $class, string $message = ''): void {
    if (!isset($message)) {
      $message = "Class .$class found.";
    }
    $this->assertStringContainsString($class, $element->getAttribute('class'), $message);

On the other side, in core/modules/system/tests/src/Functional/Pager/PagerTest.php,

  /**
   * Asserts that an element has a given class.
   *
   * @param \Behat\Mink\Element\NodeElement $element
   *   The element to test.
   * @param string $class
   *   The class to assert.
   * @param string $message
   *   (optional) A verbose message to output.
   *
   * @internal
   */
  protected function assertClass(NodeElement $element, string $class, string $message = NULL): void {
    if (!isset($message)) {
      $message = "Class .$class found.";
    }
    $this->assertTrue($element->hasClass($class), $message);
  }

To make the two match change,
, string $message = ''): void {
to
, string $message = NULL): void {

@dpi, for #6 📌 Use null coalescing assignment operator ??=: phpstan obstruction case. Closed: won't fix and $access_plugin,

However I can see there a return void;, so lets create an issue just for this, which changes the documentation, and explicitly return NULL;

I believe you have in head,

    // Return now if no options have been loaded.
    if (empty($options) || !isset($options['type'])) {
      return;
    }

in getPlugin in core/modules/views/src/Plugin/views/display/DisplayPluginBase.php. And if I follow 🐛 \Drupal\Core\Config\StorageInterface::read is typehinted as possibly returning bool, but never returns true Fixed I think the change needed should be,
* @return \Drupal\views\Plugin\views\ViewsPluginInterface
to
* @return \Drupal\views\Plugin\views\ViewsPluginInterface|null
in,

  /**
   * Get the instance of a plugin, for example style or row.
   *
   * @param string $type
   *   The type of the plugin.
   *
   * @return \Drupal\views\Plugin\views\ViewsPluginInterface
   */
  public function getPlugin($type);

in core/modules/views/src/Plugin/views/display/DisplayPluginInterface.php since,
abstract class DisplayPluginBase extends PluginBase implements DisplayPluginInterface, DependentPluginInterface {

Finally the issue perimeter could be restricted to the nullable problems,

so lets create an issue just for this

using this issue for these problems.

Still some phpstan errors,

 ------ ------------------------------------------------------------------------------------------------ 
  Line   core/modules/views/src/Plugin/views/display/DisplayPluginBase.php                               
 ------ ------------------------------------------------------------------------------------------------ 
         Ignored error pattern #^Variable \$pager in isset\(\) always exists                             
         and is not nullable\.$# in path                                                                 
         /builds/issue/drupal-3424107/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php  
         was not matched in reported errors.                                                             
         Ignored error pattern #^Variable \$style in empty\(\) always exists                             
         and is not falsy\.$# in path                                                                    
         /builds/issue/drupal-3424107/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php  
         was not matched in reported errors.                                                             
 ------ ------------------------------------------------------------------------------------------------ 
 ------ --------------------------------------------------------------------------------------------- 
  Line   core/modules/views/src/Plugin/views/display/PathPluginBase.php                               
 ------ --------------------------------------------------------------------------------------------- 
         Ignored error pattern #^Variable \$access_plugin in isset\(\) always                         
         exists and is not nullable\.$# in path                                                       
         /builds/issue/drupal-3424107/core/modules/views/src/Plugin/views/display/PathPluginBase.php  
         was not matched in reported errors.                                                          
 ------ --------------------------------------------------------------------------------------------- 
 ------ -------------------------------------------------------------------------------------------- 
  Line   core/modules/views/src/Plugin/views/style/StylePluginBase.php                               
 ------ -------------------------------------------------------------------------------------------- 
         Ignored error pattern #^Variable \$plugin in empty\(\) always exists                        
         and is not falsy\.$# in path                                                                
         /builds/issue/drupal-3424107/core/modules/views/src/Plugin/views/style/StylePluginBase.php  
         was not matched in reported errors.                                                         
 ------ -------------------------------------------------------------------------------------------- 
 ------ --------------------------------------------------------------------------------------------------- 
  Line   core/modules/views_ui/tests/src/FunctionalJavascript/PreviewTest.php                               
 ------ --------------------------------------------------------------------------------------------------- 
         Ignored error pattern #^Variable \$message in isset\(\) always exists                              
         and is not nullable\.$# in path                                                                    
         /builds/issue/drupal-3424107/core/modules/views_ui/tests/src/FunctionalJavascript/PreviewTest.php  
         was not matched in reported errors.                                                                
 ------ --------------------------------------------------------------------------------------------------- 
 [ERROR] Found 5 errors

- The phpstan errors have no line number. The corresponding items should be removed from core/phpstan-baseline.neon file.
- Following the messages,

in empty\(\) always exists and is not falsy
in isset\(\) always exists and is not nullable

since always exists, make some changes empty($A) to !$A and isset($A) to $A !== NULL. (Not always, to keep the ??= transformations still possible.)

MR mergeable. NR.

The title is also the commit message, so this should be easier to understand when searching history in the future.

Title changed. Less detailed but more clear.

The Needs Review Queue Bot → tested this issue. It no longer applies to Drupal core. Therefore, this issue status is now "Needs work".

This does not mean that the patch necessarily needs to be re-rolled or the MR rebased. Read the Issue Summary, the issue tags and the latest discussion here to determine what needs to be done.

Consult the Drupal Contributor Guide → to find step-by-step guides for working with issues.

On the coding standard decision #3436307: Change !isset to the null coalescing assignment operator ??= →