Include path risk

Hello!

The main plugin file executes some include() statements without a directory specified. The danger is that the included files will first be looked for in the current working directory (depends on the configuration, but apparently many systems have “.” as the first entry in their include_path). This caused an issue for me where the theme functions.php ran too early, because I used wp-cli from the theme directory.

The safe way would be to specify the exact directory of the file to be included, using PHP constant __DIR__ or plugin_dir_path(__FILE__)!

The issue can be reproduced in some ways:
– Use wp-cli from your theme folder. If your functions.php uses Woocommerce code it will crash, because WC is loaded after woocommerce-email-test.
– Place a functions.php (or email-trigger.php) in your website root, now the plugin will load this file instead of its own when used normally from a browser!