Create specific exception for timeout (#119)

* Create specific exception for `timeout` so a timeout can be identified downstream

* Moved to Rx\Exception namespace and added base Exception

Author: mbonneau

src/Exception/Exception.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Rx\Exception;
+
+class Exception extends \Exception
+{
+}

src/Exception/TimeoutException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Rx\Exception;
+
+class TimeoutException extends Exception
+{
+}

src/Observable.php

@@ -1552,6 +1552,9 @@ public function delay(int $delay, SchedulerInterface $scheduler = null): Observa
     }
 
     /**
+     * Errors the observable sequence if no item is emitted in the specified time.
+     * When a timeout occurs, this operator errors with an instance of Rx\Exception\TimeoutException
+     *
      * @param $timeout
      * @param ObservableInterface $timeoutObservable
      * @param SchedulerInterface $scheduler

src/Operator/TimeoutOperator.php

@@ -10,6 +10,7 @@
 use Rx\Observer\CallbackObserver;
 use Rx\ObserverInterface;
 use Rx\SchedulerInterface;
+use Rx\Exception\TimeoutException;
 
 final class TimeoutOperator implements OperatorInterface
 {
@@ -26,7 +27,7 @@ public function __construct(int $timeout, ObservableInterface $timeoutObservable
         $this->timeoutObservable = $timeoutObservable;
 
         if ($this->timeoutObservable === null) {
-            $this->timeoutObservable = new ErrorObservable(new \Exception('timeout'), $scheduler);
+            $this->timeoutObservable = new ErrorObservable(new TimeoutException('timeout'), $scheduler);
         }
     }
 

test/Rx/Functional/Operator/TimeoutTest.php

@@ -4,6 +4,7 @@
 
 use Rx\Functional\FunctionalTestCase;
 use Rx\Observable\ErrorObservable;
+use Rx\Exception\TimeoutException;
 
 class TimeoutTest extends FunctionalTestCase
 {
@@ -54,7 +55,7 @@ public function timeout_relative_time_timeout_occurs_with_default_error()
 
         $this->assertMessages(
             [
-                onError(401, new \Exception())
+                onError(401, new TimeoutException())
             ],
             $results->getMessages()
         );