Testing scenarios for domain masking via sunrise.php in WordPress

sunrise.php

<?php
// Mask Domain testing

$clientslug_custom_sunrise_domains = [
	'mask.test',
];



// quickly switch testing scenarios
$test_case = 'two';

switch ( $test_case ) {

	case 'one';

	/**
	 * origin domain must not have a path
	 *
	 * home_url filter:
	 * - load full site
	 * - links stay in mask domain
	 *
	 * redirect_canonical filter:
	 * - mask works on initial load only
	 *
	 * neither filter:
	 * - redirects to origin domain
	 */


	if ( false !== ( $key = array_search( $_SERVER['HTTP_HOST'], $clientslug_custom_sunrise_domains, true ) ) ) {
		$current_blog = get_site( 75 ); // alabama.test
		$current_site = get_network( 1 ); // This should always be 1, unless you are running multiple WordPress networks.

		$mask_domain   = $clientslug_custom_sunrise_domains[ $key ];
		$origin_domain = $current_blog->domain;

		add_filter( 'redirect_canonical', '__return_false' );

		// add_filter( 'home_url', function( $url ) use ( $mask_domain, $origin_domain ) {
		// 	return str_replace( $origin_domain, $mask_domain, $url );
		// } );

	}

	break;

	case 'two';

	/**
	 * serve only REST API over mask
	 * works on origins with or without path
	 *
	 * no filter:
	 * - serve origin domain in response data
	 *
	 * home_url filter:
	 * - can be used like other scenarios to change the domain in the response data
	 *   likely unwanted given context of not serving front-end with masked domain
	 *
	 */


	if (
		false !== ( $key = array_search( $_SERVER['HTTP_HOST'], $clientslug_custom_sunrise_domains, true ) )
		&& 0 === strpos( $_SERVER[ 'REQUEST_URI' ], '/wp-json' )
	) {
		$current_blog = get_site( 75 ); // alabama.test
		$current_site = get_network( 1 ); // This should always be 1, unless you are running multiple WordPress networks.

	}

	break;

	case 'three';

	/**
	 * origin domain has path
	 *
	 * home_url filter:
	 * - load full site with or without path, depending on str_replace
	 *
	 * redirect_canonical filter:
	 * - mask works on initial load only (no effect)
	 *
	 * no filter:
	 * - mask works on initial load only
	 * - redirect halted due to "Protect against chained redirects." check
	 */

	 if ( false !== ( $key = array_search( $_SERVER['HTTP_HOST'], $clientslug_custom_sunrise_domains, true ) ) ) {
		$current_blog = get_site( 77 ); // ms.test/arizona/
		$current_site = get_network( 1 ); // This should always be 1, unless you are running multiple WordPress networks.

		$mask_domain   = $clientslug_custom_sunrise_domains[ $key ];
		$origin_domain = $current_blog->domain;

		// add_filter( 'redirect_canonical', '__return_false' );

		// A) loads full site at mask.test/arizona (WITH origin path)
		add_filter( 'home_url', function( $url ) use ( $mask_domain, $origin_domain ) {
			return str_replace( $origin_domain, $mask_domain, $url );
		} );

		// B) load full site at mask.test (WITHOUT origin path)
		// $origin_domain .= untrailingslashit( $current_blog->path );
		// add_filter( 'home_url', function( $url ) use ( $mask_domain, $origin_domain ) {
		// 	return str_replace( $origin_domain, $mask_domain, $url );
		// } );

		// C) load full site at mask.test/party (WITHOUT origin path). mask.test does not redirect to mask.test/party
		// $mask_domain   .= untrailingslashit( '/party' );
		// $origin_domain .= untrailingslashit( $current_blog->path );
		// add_filter( 'home_url', function( $url ) use ( $mask_domain, $origin_domain ) {
		// 	return str_replace( $origin_domain, $mask_domain, $url );
		// } );


	}

	break;

}