CLI Runtime Environment Setup/Cleanup

[jjgrainger]

This issue will implement the runtime environment setup and cleanup for CLI requests. This will utilise the Runtime_Environment_Setup class to setup the WP environment before checks are run, and cleanup the environment once all checks are complete.

Acceptance Criteria

• Add a new before_wp_load hook with WP_CLI::add_hook() to implement the object-cache.php drop-in file.
  • The hook will manually (not using the WP filesystem) add the object-cache.php drop-in file to the wp-content folder.
• Create a cli.php file in the plugin root.
  • This file will be used to setup the Plugin_Check_Command both early and late in the WordPress load process.
  • The file will first check if the Plugin_Check_Command class exists.
    • If it does not this file is running before WordPress has loaded and the command will need to be setup manually.
      • This is done by loading the plugin autoload file so the class is available.
      • A new Plugin_Context for the plugin checker is created and passed to the Plugin_Check_Command constructor.
      • The Plugin_Check_Command is then registered to the WordPress CLI.
    • If the Plugin_Check_Command class does exist.
      • A check is made to see if the $context variable exists, which will be set in the Plugin_Main::add_hooks() method.
      • A new instance of the Plugin_Check_Command is created passing the $context to the constructor.
      • The Plugin_Check_Command is then registered to the WordPress CLI.
• Update the Plugin_Main::add_hooks() method to require_once the cli.php file, instead of adding the command directly to WP_CLI.
• Update the wp plugin check to run the Runtime_Environment_Setup::setup() method at the start of the commands run process if any runtime check is to be performed. This is to setup the database tables required for runtime checks.
• Update the wp plugin check to run the Runtime_Environment_Setup::cleanup() method at the end of the commands run process. This will remove the database tables and object-cache.php drop-in file if they exists.
• When running the wp plugin check command the --require flag can be used to include the cli.php file early to create the object-cache.php file and register the command.

[felixarntz]

@jjgrainger I think implementing this will be more complicated than we thought. We should probably think and discuss further how to do this. Some early feedback here:

This method will get an instance of the CLI_Runner class via the Plugin_Request_Utility::get_runner() method

This won't work since before WP is loaded, no runner will have been initialized. We may need to determine whether a runtime check is being used separately without the runner class, or we need to rethink how those runner classes work because normally it would only get initialized from the object-cache.php. But that would only get placed by the Runtime_Environment_Setup. 🤔

The runner infrastructure really seems to be the most complicated part of this architecture to figure out 😄

Update the Plugin_Check_Command class so it can be required in to WP CLI at the earliest point

One of the things that this will involve is that the actual addition of the command to WP_CLI needs to somehow be included in the file that is required early. But then we also have to remember that in that case autoloading is not set up yet, since all this would happen even before WordPress is loaded, let alone the plugin checker.

One idea I have would be to add a new file e.g. cli.php in the plugin root directory and have that be the file that needs to be required early. In that file we could include a check like "if plugin check command class does not exist, load the autoload file". Then, we would need to set up the Plugin_Context correctly based on the main file and the Plugin_Check_Command instance. We could then require_once this file in the Plugin_Main::add_hooks() method instead of having the code to add the command there. We have to consider that it needs to work in both ways, whether the --require option of WP-CLI is used or not.

[felixarntz]

@jjgrainger ACs LGTM! The only thing missing is to also conditionally call the preparation logic from Runtime_Environment_Setup in the beginning of the CLI command, since that'll still be needed to set up the DB tables (of course only relevant if any runtime check should be performed).

[jjgrainger]

Thanks @felixarntz I've updated the AC's with the Runtime_Environment_Setup to run at the start of the command process. I'll move this to todo as you've approved the rest of the AC's.