Filter Requests library to use the Fetch handler. (#1048)

As the 'http_api_transports' filter is deprecated and no longer actively
used, this filters the Requests library to always use the Fetch
transport.

## What problem is it solving?

When the kitchen sink is enabled (ie. streams extension) Requests is
using that for HTTP requests, rather than using the Fetch transport (and
does not automatically fallback to it).

## How is the problem addressed?

Filters the Requests internals to always use the transport.

## Testing Instructions

1. Load with kitchen sink
2. Observe failing requests, and no attempt to use Fetch
3. Apply Patch
4. Load with kitchen sink
5. Observe requests succeed (or fail with CORS issues via fetch).

Fixes #1047

---------

Co-authored-by: Adam Zieliński <adam@adamziel.com>

packages/playground/remote/src/lib/playground-mu-plugin/0-playground.php

@@ -1,16 +1,28 @@
 <?php
-/**
- * This is a temporary workaround to hide the 32bit integer warnings that
- * appear when using various time related function, such as strtotime and mktime.
- * Examples of the warnings that are displayed:
- * Warning: mktime(): Epoch doesn't fit in a PHP integer in <file>
- * Warning: strtotime(): Epoch doesn't fit in a PHP integer in <file>
- */
 set_error_handler(function($severity, $message, $file, $line) {
-  if (strpos($message, "fit in a PHP integer") !== false) {
-      return;
-  }
-  return false;
+	/**
+	 * This is a temporary workaround to hide the 32bit integer warnings that
+	 * appear when using various time related function, such as strtotime and mktime.
+	 * Examples of the warnings that are displayed:
+	 * Warning: mktime(): Epoch doesn't fit in a PHP integer in <file>
+	 * Warning: strtotime(): Epoch doesn't fit in a PHP integer in <file>
+	 */
+	if (strpos($message, "fit in a PHP integer") !== false) {
+		return;
+	}
+	/**
+	 * Don't complain about network errors when not connected to the network.
+	 */
+	if (
+		(
+			! defined('USE_FETCH_FOR_REQUESTS') ||
+			! USE_FETCH_FOR_REQUESTS
+		) &&
+		strpos($message, "WordPress could not establish a secure connection to WordPress.org") !== false)
+	{
+		return;
+	}
+	return false;
 });
 
 /**
@@ -114,16 +126,6 @@ function networking_disabled() {
 	mkdir(WP_CONTENT_DIR . '/fonts');
 }
 
-/**
- * Remove the default WordPress requests transports, fsockopen and cURL.
- */
-add_filter('http_api_transports', function ($transports) {
-	return array_diff($transports, [
-		'curl',
-		'streams',
-	]);
-});
-
 /**
  * The default WordPress requests transports have been disabled
  * at this point. However, the Requests class requires at least
@@ -140,30 +142,14 @@ function networking_disabled() {
 $__requests_class = class_exists( '\WpOrg\Requests\Requests' ) ? '\WpOrg\Requests\Requests' : 'Requests';
 if (defined('USE_FETCH_FOR_REQUESTS') && USE_FETCH_FOR_REQUESTS) {
 	require(__DIR__ . '/playground-includes/wp_http_fetch.php');
-	// Force-replace the default WordPress requests transports with the Fetch transport.
-	//
-	// WordPress doesn't provide a way to change the default transports,
-	// that is Curl and FSockopen. Even with all the `http_api_tranports`
-	// filter used below, WordPress tests if they are supported and will
-	// use them if their `::test()` method returns true – which it does
-	// when PHP.wasm runs with the openssl extension loaded.
-	//
-	// @see https://github.com/WordPress/wordpress-playground/pull/1045
-	$reflection = new ReflectionClass($__requests_class);
-	$property = $reflection->getProperty('transports');
-	$property->setAccessible(true);
-	$property->setValue(['Fetch' => 'Wp_Http_Fetch']);
-
-	$__requests_class::add_transport('Wp_Http_Fetch');
-
 	/**
-	 * Add Fetch transport to the list of transports that WordPress
-	 * will test for in the _get_first_available_transport() function.
-	 */
-	add_filter('http_api_transports', function ($transports) {
-		$transports[] = 'Fetch';
-		return $transports;
-	});
+	 * Force the Fetch transport to be used in Requests.
+  	 * The 'http_api_transports' filter was deprecated, and is no longer actively in use.
+  	 */
+	add_action( 'requests-requests.before_request', function( $url, $headers, $data, $type, &$options ) {
+		$options['transport'] = 'Wp_Http_Fetch';
+	}, 10, 5 );
+
 	/**
 	 * Disable signature verification as it doesn't seem to work with
 	 * fetch requests:
@@ -185,10 +171,9 @@ function networking_disabled() {
 	require(__DIR__ . '/playground-includes/wp_http_dummy.php');
 	$__requests_class::add_transport('Wp_Http_Dummy');
 
-	add_filter('http_api_transports', function ($transports) {
-		$transports[] = 'Dummy';
-		return $transports;
-	});
+	add_action( 'requests-requests.before_request', function( $url, $headers, $data, $type, &$options ) {
+		$options['transport'] = 'Wp_Http_Dummy';
+	}, 10, 5 );
 }
 
 // Configure error logging