Pending query can now be cancel()'led

Author: clue

src/Query/CancellationException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace React\Dns\Query;
+
+class CancellationException extends \RuntimeException
+{
+}

src/Query/Executor.php

@@ -53,7 +53,12 @@ public function doQuery($nameserver, $transport, $queryData, $name)
         $loop = $this->loop;
 
         $response = new Message();
-        $deferred = new Deferred();
+        $deferred = new Deferred(function ($resolve, $reject) use (&$timer, &$conn, $name) {
+            $reject(new CancellationException(sprintf('DNS query for %s has been cancelled', $name)));
+
+            $timer->cancel();
+            $conn->close();
+        });
 
         $retryWithTcp = function () use ($that, $nameserver, $queryData, $name) {
             return $that->doQuery($nameserver, 'tcp', $queryData, $name);

tests/Query/ExecutorTest.php

@@ -61,6 +61,47 @@ public function resolveShouldCreateTcpRequestIfRequestIsLargerThan512Bytes()
         $this->executor->query('8.8.8.8:53', $query, function () {}, function () {});
     }
 
+    /** @test */
+    public function resolveShouldCloseConnectionWhenCancelled()
+    {
+        if (!interface_exists('React\Promise\CancellablePromiseInterface')) {
+            $this->markTestSkipped('Skipped missing CancellablePromiseInterface');
+        }
+
+        $conn = $this->createConnectionMock();
+        $conn->expects($this->once())->method('close');
+
+        $timer = $this->getMock('React\EventLoop\Timer\TimerInterface');
+        $this->loop
+            ->expects($this->any())
+            ->method('addTimer')
+            ->will($this->returnValue($timer));
+
+        $this->executor = $this->createExecutorMock();
+        $this->executor
+            ->expects($this->once())
+            ->method('createConnection')
+            ->with('8.8.8.8:53', 'udp')
+            ->will($this->returnValue($conn));
+
+        $query = new Query('igor.io', Message::TYPE_A, Message::CLASS_IN, 1345656451);
+        $promise = $this->executor->query('8.8.8.8:53', $query);
+
+        $promise->cancel();
+
+        $errorback = $this->createCallableMock();
+        $errorback
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->logicalAnd(
+                $this->isInstanceOf('React\Dns\Query\CancellationException'),
+                $this->attribute($this->equalTo('DNS query for igor.io has been cancelled'), 'message')
+            )
+        );
+
+        $promise->then($this->expectCallableNever(), $errorback);
+    }
+
     /** @test */
     public function resolveShouldRetryWithTcpIfResponseIsTruncated()
     {