WordPress-Extra: demand for exit/die to always use parentheses

[jrfnl]

Description

Follow up after PR #2646, pulled separately as the decision point is different.

PHPCSExtra offers two new sniffs to choose from related to whether exit/die calls should use parentheses or not.

This PR proposes to add one of these rules to WordPress-Extra, with an eye to eventually moving the rule to WordPress-Core after a Make post.

WordPress Core currently contains 395 calls to exit/die.

If we look at the metrics the new sniffs generate, the current state of WordPress-Core is inconsistent, though leans towards only requiring parentheses when parameters are passed:

Exit/die with parentheses:
        no                     =>  275 ( 69.62%)
        yes, with parameter(s) =>   74 ( 18.73%)
        yes                    =>   46 ( 11.65%)
        -----------------------------------------
        total                  =>  395 (100.00%)

Having said that, the WordPress Coding Standards handbook already contains the following rule regarding object instantiations, for which parentheses are also optional:

When instantiating a new object instance, parenthesis must always be used, even when not strictly necessary.

Ref: https://github.com/WordPress/wpcs-docs/blob/master/wordpress-coding-standards/php.md#object-instantiation

In this commit, I propose to add a rule to demand that calls to exit/die always use parentheses.

Reasoning:

• Creates consistency with the "object instantiations" rule.
• Yes, it will cause code-churn in Core if the rule would get adopted in Core, but it will also create more consistency between calls to exit/die.
• Demanding parentheses is also in line with PERCS, which means that the rule doesn't raise the barrier to entry for new contributors to WordPress.

👉🏻 Having said this, I can also imagine us holding off on adding this rule to WordPress-Extra and going straight for a Make post to add the rule to WordPress-Core.
This would avoid/prevent confusion if a discussion about this on Make would yield another decision (forbid parentheses except when there are parameters).

In other words, this PR is very much a suggestion, not a definitive proposal, and whether or not we should merge it will depend on people leaving opinions about this topic.

So.... opinions please ?

Suggested changelog entry

• WordPress-Extra: the following additional sniffs has been added to the ruleset: Universal.PHP.RequireExitDieParentheses.

[dingo-d]

The safest route without ruffling some feathers would be to create a make post, then wait for comments, and then introduce it.

I'm always for aligning WPCS with official PHP recommendations (lowers the friction), so my vote is to add parentheses.

[jrfnl]

@dingo-d Thanks for your input. I'd be happy to go that route, though someone else will have to do the Make post (but can use the text from the commit message above as inspiration).