Problem/Motivation
Drupal 10.0.0 stable was released on: 15 Dec 2022 by the Drupal core team
            
              https://www.drupal.org/project/drupal/releases/10.0.0 →
            
Thank you so much!
The current composer require status for this module under Drupal 10
composer create-project drupal/recommended-project:~10 /var/www/html/sandboxes/drupal10anchor_link
cd  /var/www/html/sandboxes/drupal10anchor_link/
composer require drupal/anchor_link;
is having the following problem
Using version ^2.5 for drupal/anchor_link
./composer.json has been updated
Running composer update drupal/anchor_link
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.
  Problem 1
    - drupal/anchor_link 2.x-dev is an alias of drupal/anchor_link dev-2.x and thus requires it to be installed too.
    - drupal/anchor_link[dev-2.x, 2.5.0] require drupal/fakeobjects ^1.0 -> satisfiable by drupal/fakeobjects[1.0.0, 1.1.0, 1.x-dev].
    - drupal/fakeobjects 1.0.0 requires drupal/core ^8 -> found drupal/core[8.0.0-beta6, ..., 8.9.x-dev] but the package is fixed to 10.0.0-alpha4 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - drupal/fakeobjects[1.1.0, ..., 1.x-dev] require drupal/core ^8 || ^9 -> found drupal/core[8.0.0-beta6, ..., 8.9.x-dev, 9.0.0-alpha1, ..., 9.5.x-dev] but the package is fixed to 10.0.0-alpha4 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
    - Root composer.json requires drupal/anchor_link ^2.5 -> satisfiable by drupal/anchor_link[2.5.0, 2.x-dev (alias of dev-2.x)].
Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.
You can also try re-running composer require with an explicit version constraint, e.g. "composer require drupal/anchor_link:*" to figure out if any version is installable, or "composer require drupal/anchor_link:^2.1" if you know which you need.
Installation failed, reverting ./composer.json and ./composer.lock to their original content.
composer create-project drupal/recommended-project:~9 /var/www/html/sandboxes/drupal9anchor_link
cd /var/www/html/sandboxes/drupal9anchor_link/
composer config minimum-stability dev
composer require drupal/anchor_link:1.x-dev
composer require drupal/core-dev:~9 --with-all-dependencies
composer require mglaman/drupal-check --dev
composer require phpspec/prophecy-phpunit:^2 --dev 
php vendor/bin/drupal-check -d web/modules/contrib/anchor_link/
Output: 
4/4 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%
 ------ -------------------------------------------------------------------- 
  Line   src/Plugin/CKEditorPlugin/AnchorLink.php                            
 ------ -------------------------------------------------------------------- 
  23     Call to deprecated function drupal_get_path():                      
         in drupal:9.3.0 and is removed from drupal:10.0.0. Use              
           \Drupal\Core\Extension\ExtensionPathResolver::getPath() instead.  
  56     Call to deprecated function drupal_get_path():                      
         in drupal:9.3.0 and is removed from drupal:10.0.0. Use              
           \Drupal\Core\Extension\ExtensionPathResolver::getPath() instead.  
  60     Call to deprecated function drupal_get_path():                      
         in drupal:9.3.0 and is removed from drupal:10.0.0. Use              
           \Drupal\Core\Extension\ExtensionPathResolver::getPath() instead.  
  64     Call to deprecated function drupal_get_path():                      
         in drupal:9.3.0 and is removed from drupal:10.0.0. Use              
           \Drupal\Core\Extension\ExtensionPathResolver::getPath() instead.  
 ------ -------------------------------------------------------------------- 
 ------ -------------------------------------------------------------------- 
  Line   src/Plugin/CKEditorPlugin/FakeObjects.php                           
 ------ -------------------------------------------------------------------- 
  24     Call to deprecated function drupal_get_path():                      
         in drupal:9.3.0 and is removed from drupal:10.0.0. Use              
           \Drupal\Core\Extension\ExtensionPathResolver::getPath() instead.  
 ------ -------------------------------------------------------------------- 
 ------ ----------------------------------------------------------------------- 
  Line   src/Plugin/Linkit/Matcher/CKEditorAnchorLinkMatcher.php                
 ------ ----------------------------------------------------------------------- 
  18     Class                                                                  
         Drupal\anchor_link\Plugin\Linkit\Matcher\CKEditorAnchorLinkMatcher     
         extends unknown class Drupal\linkit\MatcherBase.                       
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols    
  24     Instantiated class Drupal\linkit\Suggestion\SuggestionCollection not   
         found.                                                                 
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols    
  28     Instantiated class Drupal\linkit\Suggestion\DescriptionSuggestion not  
         found.                                                                 
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols    
  29     Call to an undefined method                                            
         Drupal\anchor_link\Plugin\Linkit\Matcher\CKEditorAnchorLinkMatcher::t  
         ().                                                                    
  29     Call to method setLabel() on an unknown class                          
         Drupal\linkit\Suggestion\DescriptionSuggestion.                        
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols    
  31     Call to an undefined method                                            
         Drupal\anchor_link\Plugin\Linkit\Matcher\CKEditorAnchorLinkMatcher::t  
         ().                                                                    
  33     Call to method addSuggestion() on an unknown class                     
         Drupal\linkit\Suggestion\SuggestionCollection.                         
         💡 Learn more at https://phpstan.org/user-guide/discovering-symbols    
 ------ ----------------------------------------------------------------------- 
 [ERROR] Found 12 errors                                                        
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Proposed resolution
- Support Drupal ~10 and change all deprecated packages, classes, functions, asset libraries to the Drupal 10 way
 
- Real physical testing with Drupal ~10
 
- Automated upgrade to Drupal ~10
 
Remaining tasks
- ✅ File an issue
 
- ✅ Addition/Change/Update/Fix
 
- ✅ Testing to ensure no regression
 
- ➖ Automated unit testing coverage
 
- ➖ Automated functional testing coverage
 
- ➖ UX/UI designer responsibilities
 
- ➖ Readability
 
- ➖ Accessibility
 
- ➖ Performance
 
- ➖ Security
 
- ➖ Documentation
 
- ✅ Code review by maintainers
 
- ✅ Full testing and approval
 
- ✅ Credit contributors
 
- ✅ Review with the product owner
 
- ✅ Release notes snippet
 
- ✅ Release 
            
              anchor_link-1.10.0 →
             , 
            
              anchor_link-2.6.0 →
            
 
API changes
Data model changes
Release notes snippet