WP HTTP API: simulated transport for troubleshooting and testing

wp-http-simulated.php

<?php
/**
 * Once setup, this WP HTTP transport does a couple of things:
 *
 * 1) it means calls to wp_http_get() etc don't result in anything
 *    actually being sent on the wire
 *
 * 2) if a save directory is specified it will save a text representation
 *    of the request in that directory
 *
 * Occasionally useful for debugging purposes.
 */
class WP_Http_Simulated {
	protected static $saved_requests_dir = '';

	public static function setup( $save_dir = '' ) {
		self::$saved_requests_dir = $save_dir;

		add_filter( 'http_api_transports', function( $transports ) {
			array_unshift( $transports, 'simulated' );
			return $transports;
		} );
	}

	/**
	 * Confirm that this transport is viable, otherwise WP_Http will skip
	 * to the next available transport.
	 *
	 * @return bool
	 */
	public static function test() {
		return true;
	}

	/**
	 * Save a representation of the request (if a saved requests directory
	 * has been specified) and return a 200 OK response to the caller.
	 *
	 * @param string $url
	 * @param array  $args
	 *
	 * @return array
	 */
	public function request( $url, array $args = null ) {
		if ( ! empty( self::$saved_requests_dir ) ) {
			$base_filename = self::$saved_requests_dir . date_i18n( 'ymd-his-' ) . uniqid();
			file_put_contents( $base_filename, "$url\n" . print_r( $args, true ) );
		}

		return [
			'headers' => [
				'date'         => date_i18n( 'Y-m-d H:i:s' ),
				'server'       => 'Simulated response',
				'content-type' => 'application/json'
			],
			'body' => json_encode( [
				'data' => hash( 'md5', rand( 0, PHP_INT_MAX ) )
			] ),
			'response' => [
				'code'    => '200',
				'message' => 'OK'
			],
			'cookies' => []
		];
	}
}

WP_Http_Simulated::setup( '/html/someproject.com/wp-content/uploads/http-requests' );