Introduce messenger interface to v2.x.x

src/Messenger.php

@@ -13,7 +13,7 @@
 use WyriHaximus\React\ChildProcess\Messenger\Messages\Message;
 use WyriHaximus\React\ChildProcess\Messenger\Messages\Rpc;
 
-class Messenger extends EventEmitter
+class Messenger extends EventEmitter implements MessengerInterface
 {
     const INTERVAL = 0.1;
     const TERMINATE_RPC = 'wyrihaximus.react.child-process.messenger.terminate';

src/MessengerInterface.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace WyriHaximus\React\ChildProcess\Messenger;
+
+use WyriHaximus\React\ChildProcess\Messenger\Messages\ActionableMessageInterface;
+use WyriHaximus\React\ChildProcess\Messenger\Messages\Error;
+use WyriHaximus\React\ChildProcess\Messenger\Messages\LineInterface;
+use WyriHaximus\React\ChildProcess\Messenger\Messages\Message;
+use WyriHaximus\React\ChildProcess\Messenger\Messages\Rpc;
+
+interface MessengerInterface
+{
+    /**
+     * @param string   $target
+     * @param callable $listener
+     */
+    public function registerRpc($target, callable $listener);
+
+    /**
+     * @param string $target
+     */
+    public function deregisterRpc($target);
+
+    /**
+     * @param  string $target
+     * @return bool
+     */
+    public function hasRpc($target);
+
+    /**
+     * @param $target
+     * @param $payload
+     * @return React\Promise\PromiseInterface
+     */
+    public function callRpc($target, $payload);
+
+    /**
+     * @param Message $message
+     */
+    public function message(Message $message);
+
+    /**
+     * @param Error $error
+     */
+    public function error(Error $error);
+
+    /**
+     * @param  string          $uniqid
+     * @return OutstandingCall
+     */
+    public function getOutstandingCall($uniqid);
+
+    /**
+     * @param  Rpc                    $rpc
+     * @return \React\Promise\Promise
+     */
+    public function rpc(Rpc $rpc);
+
+    /**
+     * @param  ActionableMessageInterface $line
+     * @return LineInterface
+     */
+    public function createLine(ActionableMessageInterface $line);
+
+    /**
+     * @return \React\Promise\Promise
+     */
+    public function softTerminate();
+
+    /**
+     * @param string $line
+     */
+    public function write($line);
+}