More readable and faster check for array of arrays in register_rest_route()

[TobiasBg]

In [54339] for #51986,

<?php
if ( count( array_filter( $arg_group['args'], 'is_array' ) ) !== count( $arg_group['args'] ) ) {

was used as a custom implementation of an any() function.

This is not very readable and not that nice performance-wise (array_filter() will always loop the full array, even though we are only interested in finding one (the first) non-array).

This should be simplified to a foreach loop that is left early once a match is found, for better readability and higher performance, e.g.:

<?php
foreach( $arg_group['args'] as $arg ) {
        if ( ! is_array( $arg ) ) {
                _doing_it_wrong(
                        __FUNCTION__,
                        sprintf(
                                /* translators: 1: $args, 2: The REST API route being registered. */
                                __( 'REST API %1$s should be an array of arrays. Non-array value detected for %2$s.' ),
                                '<code>$args</code>',
                                '<code>' . $clean_namespace . '/' . trim( $route, '/' ) . '</code>'
                        ),
                        '6.1.0'
                );
                break; // Leave the foreach loop once one non-array argument was found.
        }
}

(Follow-up to #51986 where this suggestion missed the deadline for 6.1-RC1, taking into account the linked-to Slack discussion in that ticket, regarding the target milestone. The Version of this ticket should be 6.1, but that does not yet exist in Trac.)

Trac ticket: https://core.trac.wordpress.org/ticket/56804

[SergeyBiryukov]

Thanks for the ticket! The suggested code does look better to me in terms of readability and performance.

I believe this can be included in 6.1 RC2.

[audrasjb]

As per today's bug scrub: @costdev and I both reviewed the proposed PR, and it looks like it's good to go, thanks!

[SergeyBiryukov]

In 54518:

REST API: Simplify the check for an array of arrays in register_rest_route().

The previous implementation of checking whether the args parameter is an array of arrays used array_filter(), which would always loop the full array, even though we are only interested in finding one (the first) non-array to display a _doing_it_wrong() message.

This commit aims to improve readability and performance of this check by using a foreach loop instead, leaving it as soon as the first non-array argument is found.

Follow-up to [54339].

Props TobiasBg, audrasjb, costdev, SergeyBiryukov.
Fixes #56804.

Merged in r54518.