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Closed 5 years ago.

There's a lot of if( !function_exists(... { require ABSPATH . '/file.php in the industry. We didn't crash, the world still lives, yet I wonder - isn't this one of the worst things you can do in an event driven system like WordPress is?

At first sight, you're just including classes / functions that do nothing by the require alone, ye? Wrong. If you need to require a file, you also plan on using a function. Inside that function, there could be do_action that should only fire once and at the right time, yet you're firing them here. What if a critical piece of code relies on that action to fire at a certain moment when a resource is available?

Then, shouldn't we have a lot of errors in the eco-system?

What am I misunderstanding here? To me, in theory, this seems like you open yourself to so many fatal errors doing this, yet we're all fine.