wp_enqueue_script() with an alias handle doesn't work in footer

[kovshenin]

When registering an alias script (similar to how jquery is an alias for jquery-core and jquery-migrate) in the footer, none of the declared dependencies are processed.

This works:

add_action( 'wp_enqueue_scripts', function() {
	wp_register_script( 'foo', false, array( 'bar', 'baz' ), '1.0' );
	wp_register_script( 'bar', home_url( 'bar.js' ), array(), '1.0' );
	wp_register_script( 'baz', home_url( 'baz.js' ), array(), '1.0' );

	wp_enqueue_script( 'foo' );
});

This doesn't (no output):

add_action( 'wp_enqueue_scripts', function() {
	wp_register_script( 'foo', false, array( 'bar', 'baz' ), '1.0', true );
	wp_register_script( 'bar', home_url( 'bar.js' ), array(), '1.0', true );
	wp_register_script( 'baz', home_url( 'baz.js' ), array(), '1.0', true );

	wp_enqueue_script( 'foo' );
});

[kovshenin]

In 35643.diff​: Move the src empty check to do_item() after groups have been checked.

[grapplerulrich]

Have you tried the patch with jQuery? I tried the patch with the following snippet and it did not work.

<?php
function grappler_move_jquery_to_footer( &$scripts ) {
    if( is_admin() ) {
        return;
    }
    $scripts->add_data( 'jquery', 'group', 1 );
    $scripts->add_data( 'jquery-core', 'group', 1 );
    $scripts->add_data( 'jquery-migrate', 'group', 1 );
}
add_action( 'wp_default_scripts', 'grappler_move_jquery_to_footer', 11 );

When I was trying to make it work I looked at ​https://github.com/WordPress/WordPress/blob/4.4-branch/wp-includes/class.wp-dependencies.php#L111. It adds the alias script to the header without checking the group.

[kovshenin]

@grapplerulrich Yeah it works with jQuery. The code you referenced is the code that's moved out of the dependencies class and into the scripts and styles subclasses instead. Are you sure you applied the patch? And also, make sure no other header scripts declare a jquery dependency, otherwise WordPress will still obey the dependency and print jQuery in the header, regardless of its footer group.

[grapplerulrich]

The patch works perfectly. I did not apply the patch correctly. Forgot to remove the code in class.wp-dependencies.php

[ocean90]

In 36559:

Tests: Add a test for testing wp_enqueue_script() with an alias handle in the footer.

Props kovshenin.
See #35643.

[ocean90]

This was fixed in [36550].