Standardize checking for WP_DEBUG

[nacin]

The Codex recommends define('WP_DEBUG', true) or define('WP_DEBUG', false). However, WP_DEBUG is inconsistently checked whether should WP_DEBUG be identical or equal to those values.

Thus, define('WP_DEBUG', 1) will not turn all feedback on, and define('WP_DEBUG', 0) will not turn all feedback off.

Two patches attached, depending on whether it should be standardized to true == WP_DEBUG or true === WP_DEBUG.

[nacin]

true === WP_DEBUG

[nacin]

true == WP_DEBUG

[hakre]

the expression of true == WP_DEBUG is completely equal to the expression of WP_DEBUG. To keep things simple, I would prefer the later one. Same applies to false == WP_DEBUG which is equal to !WP_DEBUG.

[scribu]

Consider the case where WP_DEBUG is not defined at all:

var_dump(true == WP_DEBUG); // Result: bool(true)

I vote for '==='.

[strider72]

Per discussion on wp-hackers: The docs say that the values should be boolean, thus === is the way to go.

​http://lists.automattic.com/pipermail/wp-hackers/2009-November/028395.html

[azaozz]

Don't see a good reason to explicitly forbid other values that evaluate to true. Also true == WP_DEBUG doesn't seem to have a purpose. Looking at other boolean constants, most are checked with:

if ( defined('CONSTANT') && CONSTANT )
// true
...
if ( !defined('CONSTANT') || !CONSTANT )
// false

which seems clear and concise. So if we are standardizing this perhaps that is the way to go.

[nacin]

Better patch for true == WP_DEBUG route

[dd32]

Is there any good reason for code like this:

 if ( ! defined('WP_DEBUG') || ( defined('WP_DEBUG') && !WP_DEBUG ) ) {

Which is exactly the same as:

 if ( ! defined('WP_DEBUG') || !WP_DEBUG ) {

I agree that adding == and === into it complicates things.

We could even add to wp-settings:

if ( ! defined('WP_DEBUG') ) define('WP_DEBUG', false);

if that makes it easier?

[westi]

I'll look into this and fix it later today :-)

[nacin]

wp-settings.php will now set {{WP_DEBUG == false}}, making the {{defined(WP_DEBUG)}} check no longer needed in core or in plugins.

[nacin]

(Oops, poor Wiki formatting on my part.)

Thanks, westi.

New patch following dd32's logic, and to prevent an undefined constant from evaluating to true as scribu pointed out.

The only concern I might see with this route is that a plugin might be only checking for define( WP_DEBUG ) and not actually checking if ( WP_DEBUG ) as well.

This reminds me of #10602 as well, regarding WP_CACHE.

[automattor]

(In [12207]) Ensure WP_DEBUG is always defined and simplify the checks on it. Fixes #11090 props nacin.