Drupal 9 plan

Going to check it at DrupalCon Amsterdam 2019.

It appears like the module has few files containing dead code which are probably leftovers from D7:

1. includes/DataHandler.inc
2. tests/data.test
3. tests/data.test.inc
4. views/views_handler_field_data_markup.inc

Sadly, tests weren't ported from D7 and are useless right now.

I've raised #3091442 for this.

Here's the drupal-check report excluding those files:

 ~/.config/composer/vendor/bin/drupal-check -d -- .
 25/25 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%

 ------ ------------------------------------------------------------------------- 
  Line   data.module                                                              
 ------ ------------------------------------------------------------------------- 
  227    Call to deprecated function db_escape_table():                           
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call escapeTable() on it. For example,                                   
  391    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
 ------ ------------------------------------------------------------------------- 

 ------ ------------------------------------------------------------------------- 
  Line   data_search/data_search.admin.inc                                        
 ------ ------------------------------------------------------------------------- 
  15     Call to deprecated function drupal_set_message():                        
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.                 
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.     
  70     Call to deprecated function drupal_render():                             
         as of Drupal 8.0.x, will be removed before Drupal 9.0.0. Use the         
  77     Call to deprecated function drupal_render_children():                    
         in Drupal 8.0.x and will be removed before 9.0.0. Avoid early            
         rendering when possible or loop through the elements and render them as  
         they are available.                                                      
 ------ ------------------------------------------------------------------------- 

 ------ ------------------------------------------------------------------------- 
  Line   data_search/data_search.install                                          
 ------ ------------------------------------------------------------------------- 
  17     Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  18     Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  19     Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
 ------ ------------------------------------------------------------------------- 

 ------ ------------------------------------------------------------------------- 
  Line   data_search/data_search.module                                           
 ------ ------------------------------------------------------------------------- 
  88     Call to deprecated function db_query_range():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call queryRange() on it. For example,                                    
  92     Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  101    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  117    Call to deprecated function db_update():                                 
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call update() on it. For example,                                        
  135    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  137    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  156    Call to deprecated function db_escape_table():                           
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call escapeTable() on it. For example,                                   
  160    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
  162    Call to deprecated function db_query():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get        
         a database connection injected into your service from the container and  
         call query() on it. For example,                                         
 ------ ------------------------------------------------------------------------- 

 ------ ---------------------------------------------------------------------- 
  Line   src/Form/TableConfigDeleteForm.php                                    
 ------ ---------------------------------------------------------------------- 
  41     Call to deprecated function drupal_set_message():                     
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.              
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.  
 ------ ---------------------------------------------------------------------- 

 ------ ---------------------------------------------------------------------------------- 
  Line   src/Form/TableConfigForm.php                                                      
 ------ ---------------------------------------------------------------------------------- 
  128    Call to deprecated function drupal_set_message():                                 
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.                          
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.              
  134    Call to deprecated function drupal_set_message():                                 
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.                          
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.              
  140    Call to deprecated function drupal_set_message():                                 
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.                          
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.              
  144    Call to deprecated method urlInfo() of class Drupal\Core\Entity\EntityInterface:  
         in Drupal 8.0.0, intended to be removed in Drupal 9.0.0                           
         Use \Drupal\Core\Entity\EntityInterface::toUrl() instead.                         
 ------ ---------------------------------------------------------------------------------- 

 ------ --------------------------------------------------------------------------------------------------------------------- 
  Line   src/Plugin/views/field/DataViewsField.php                                                                            
 ------ --------------------------------------------------------------------------------------------------------------------- 
  15     Class Drupal\data\Plugin\views\field\DataViewsField extends deprecated class Drupal\views\Plugin\views\field\Field:  
         in Drupal 8.3.x and will be removed before 9.0.0                                                                     
         Use \Drupal\views\Plugin\views\field\EntityField instead.                                                            
 ------ --------------------------------------------------------------------------------------------------------------------- 

 ------ -------------------------------------------------------------------------- 
  Line   src/Table.php                                                             
 ------ -------------------------------------------------------------------------- 
  47     Call to deprecated function db_escape_table():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container and   
         call escapeTable() on it. For example,                                    
  68     Call to deprecated function db_table_exists():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call tableExists() on it. For example,             
  72     Call to deprecated function db_create_table():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call createTable() on it. For example,             
  75     Call to deprecated function drupal_set_message():                         
         in Drupal 8.5.0 and will be removed before Drupal 9.0.0.                  
         Use \Drupal\Core\Messenger\MessengerInterface::addMessage() instead.      
  186    Call to deprecated function db_delete():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container and   
         call delete() on it. For example,                                         
  263    Call to deprecated function db_add_field():                               
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call addField() on it. For example,                
  294    Call to deprecated function db_add_index():                               
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call addIndex() on it. For example,                
  312    Call to deprecated function db_drop_index():                              
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call dropIndex() on it. For example,               
  333    Call to deprecated function db_add_unique_key():                          
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call addUniqueKey() on it. For example,            
  353    Call to deprecated function db_drop_unique_key():                         
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call dropUniqueKey() on it. For example,           
  401    Call to deprecated function db_add_primary_key():                         
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call addPrimaryKey() on it. For example,           
  418    Call to deprecated function db_drop_primary_key():                        
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call dropPrimaryKey() on it. For example,          
  465    Call to deprecated function db_change_field():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call changeField() on it. For example,             
  483    Call to deprecated function db_drop_field():                              
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call dropField() on it. For example,               
  505    Call to deprecated function db_table_exists():                            
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call tableExists() on it. For example,             
  506    Call to deprecated function db_drop_table():                              
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container, get  
         its schema driver, and call dropTable() on it. For example,               
  511    Call to deprecated function db_delete():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container and   
         call delete() on it. For example,                                         
  531    Call to deprecated function db_delete():                                  
         as of Drupal 8.0.x, will be removed in Drupal 9.0.0. Instead, get         
         a database connection injected into your service from the container and   
         call delete() on it. For example,                                         
 ------ -------------------------------------------------------------------------- 

                                                                                                                        
 [ERROR] Found 41 errors                                                                                                
                                                                                                                        

I've raised #3091458: Deprecations removal: data_search module., #3091460: Deprecations removal. Drupal 9 readiness and #3091461: Deprecations removal: misc files for fixing deprecations.

Removed deprecated methods please review.

I found these issues:

------ ----------------------------------------------------------------------------------------------------------------------------------------------- 
  Line   data_search/data_search.module                                                                                                                 
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------- 
  99     Call to deprecated function search_index():                                                                                                    
         in drupal:8.8.0 and is removed from drupal:9.0.0. Use                                                                                          
         \Drupal\search\SearchIndex::index() instead.                                                                                                   
  122    Call to deprecated constant REQUEST_TIME: Deprecated in drupal:8.3.0 and is removed from drupal:9.0.0. Use \Drupal::time()->getRequestTime();  
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------- 

 ------ ----------------------------------------------------------------------------------------------------------------------------------------------- 
  Line   src/Entity/TableConfig.php                                                                                                                     
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------- 
  58     Call to deprecated constant REQUEST_TIME: Deprecated in drupal:8.3.0 and is removed from drupal:9.0.0. Use \Drupal::time()->getRequestTime();  
 ------ ----------------------------------------------------------------------------------------------------------------------------------------------- 
                                                                                                          
 [ERROR] Found 6 errors