add-assets-before-enqueue-scripts.php

<?php
/**
 * Plugin Name: Add Assets before wp_enqueue_scripts
 * Description: Test case to debug AMP plugin source attribution problems.
 * Author: Weston Ruter
 * Author URI: https://weston.ruter.net/
 * Plugin URI: https://amp-wp.org
 * License: GPLv2 or later
 */

namespace Add_Assets_Before_WP_Enqueue_Scripts;

/**
 * Register styles.
 *
 * @param \WP_Styles $styles Styles.
 */
function register_styles( \WP_Styles $styles ) {
	$styles->add(
		'stylesheet-registered-at-default-styles',
		plugin_dir_url( __FILE__ ) . 'stylesheet-registered-at-default-styles.css'
	);
}
add_action( 'wp_default_styles', __NAMESPACE__ . '\register_styles' );

/**
 * Register scripts.
 *
 * @param \WP_Scripts $scripts Scripts.
 */
function register_scripts( \WP_Scripts $scripts ) {
	$scripts->add(
		'script-registered-at-default-scripts',
		plugin_dir_url( __FILE__ ) . 'script-registered-at-default-scripts.js'
	);
}
add_action( 'wp_default_scripts', __NAMESPACE__ . '\register_scripts' );

/**
 * Enqueue styles at init.
 */
function enqueue_stylesheet_at_init() {
	global $pagenow;
	if ( is_admin() || 'index.php' !== $pagenow ) {
		return;
	}
	wp_enqueue_style(
		'stylesheet-enqueued-at-init',
		plugin_dir_url( __FILE__ ) . 'stylesheet-enqueued-at-init.css',
		[],
		'0.1'
	);
	wp_enqueue_style( 'stylesheet-registered-at-default-styles' );

	wp_enqueue_script(
		'script-enqueued-at-init',
		plugin_dir_url( __FILE__ ) . 'script-enqueued-at-init.js',
		[],
		'0.1',
		true
	);
	wp_enqueue_script( 'script-registered-at-default-scripts' );
}
add_action( 'init', __NAMESPACE__ . '\enqueue_stylesheet_at_init', 100 );

/**
 * Add inline style.
 */
function add_inline_theme_stylesheet() {
	wp_enqueue_style( 'stylesheet-enqueued-normally' );
	wp_enqueue_style(
		'script-enqueued-normally',
		plugin_dir_url( __FILE__ ) . 'stylesheet-enqueued-normally.css',
		[],
		'0.1'
	);

	wp_enqueue_script( 'script-enqueued-normally' );
	wp_enqueue_script(
		'script-enqueued-normally',
		plugin_dir_url( __FILE__ ) . 'script-enqueued-normally.js',
		[],
		'0.1',
		true
	);

	wp_add_inline_style( get_stylesheet() . '-style', 'body { border-left: solid 50px lime; }' );
}
add_action( 'wp_enqueue_scripts', __NAMESPACE__ . '\add_inline_theme_stylesheet', 11 );

script-enqueued-at-init.js

console.info('script-enqueued-at-init');

script-enqueued-normally.js

console.info('script-enqueued-normally');

script-registered-at-default-scripts.js

console.info('script-registered-at-default-scripts');

stylesheet-enqueued-at-init.css

body {
	border-right: solid 50px blue !important;
}

stylesheet-enqueued-normally.css

body {
	border-bottom: solid 50px yellow !important;
}

stylesheet-registered-at-default-styles.css

body {
	border-top: solid 50px red !important;
}