More predictable cancellation by requiring cancellation support

Cancellation support has been backported from promise v2.1 to v1.2,
so we can now rely on cancellation support being available for both
major versions.

Author: clue

README.md

@@ -132,13 +132,6 @@ If no cancellation handler is passed to the `Promise` constructor, then invoking
 its `cancel()` method it is effectively a NO-OP.
 This means that it may still be pending and can hence continue consuming resources.
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then this is also a NO-OP,
-as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-It is assumed that if you're actually still stuck on PHP 5.3, resource cleanup
-is likely one of your smaller problems. 
-
 For more details on the promise cancellation, please refer to the
 [Promise documentation](https://github.com/reactphp/promise#cancellablepromiseinterface).
 
@@ -168,11 +161,6 @@ handling the `cancel()` call:
   The same happens if the input `$promise` does not register a
   [cancellation handler](#cancellation-handler). 
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then the `cancel()` method
-is not available, as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-
 #### Output cancellation
 
 Similarily, you can also explicitly `cancel()` the resulting promise like this:
@@ -229,11 +217,6 @@ This means that while the resulting promise will still be rejected after the
 timeout, the underlying input `$promise` may still be pending and can hence
 continue consuming resources.
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then the `cancel()` method
-is not available, as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-
 #### Collections
 
 If you want to wait for multiple promises to resolve, you can use the normal promise primitives like this:
@@ -280,11 +263,6 @@ $timer->cancel();
 
 This will abort the timer and *reject* with a `RuntimeException`.
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then the `cancel()` method
-is not available, as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-
 ### reject()
 
 The `reject($time, LoopInterface $loop)` function can be used to create a new Promise
@@ -311,11 +289,6 @@ $timer->cancel();
 
 This will abort the timer and *reject* with a `RuntimeException`.
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then the `cancel()` method
-is not available, as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-
 ### TimeoutException
 
 The `TimeoutException` extends PHP's built-in `RuntimeException`.
@@ -335,12 +308,6 @@ The recommended way to install this library is [through composer](http://getcomp
 }
 ```
 
-> Note: If you're stuck on legacy versions (PHP 5.3), then the `cancel()` method
-is not available,
-as the Promise cancellation API is currently only available in
-[react/promise v2.1.0](https://github.com/reactphp/promise)
-which in turn requires PHP 5.4 or up.
-
 ## License
 
 MIT

composer.json

@@ -17,6 +17,6 @@
     "require": {
         "php": ">=5.3",
         "react/event-loop": "~0.4.0|~0.3.0",
-        "react/promise": "~2.0|~1.1"
+        "react/promise": "~2.1|~1.2"
     }
 }

tests/FunctionRejectTest.php

@@ -25,10 +25,6 @@ public function testCancelingPromiseWillRejectTimer()
     {
         $promise = Timer\reject(0.01, $this->loop);
 
-        if (!($promise instanceof CancellablePromiseInterface)) {
-            $this->markTestSkipped('Outdated Promise API');
-        }
-
         $promise->cancel();
 
         $this->expectPromiseRejected($promise);

tests/FunctionResolveTest.php

@@ -38,10 +38,6 @@ public function testCancellingPromiseWillCancelLoopTimer()
 
         $promise = Timer\resolve(0.01, $loop);
 
-        if (!($promise instanceof CancellablePromiseInterface)) {
-            $this->markTestSkipped('Outdated Promise API');
-        }
-
         $loop->expects($this->once())->method('cancelTimer')->with($this->equalTo($timer));
 
         $promise->cancel();
@@ -51,10 +47,6 @@ public function testCancelingPromiseWillRejectTimer()
     {
         $promise = Timer\resolve(0.01, $this->loop);
 
-        if (!($promise instanceof CancellablePromiseInterface)) {
-            $this->markTestSkipped('Outdated Promise API');
-        }
-
         $promise->cancel();
 
         $this->expectPromiseRejected($promise);

tests/FunctionTimeoutTest.php

@@ -62,10 +62,6 @@ public function testPendingWillRejectOnTimeout()
 
     public function testPendingCancellableWillBeCancelledOnTimeout()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = $this->getMock('React\Promise\CancellablePromiseInterface');
         $promise->expects($this->once())->method('cancel');
 
@@ -76,10 +72,6 @@ public function testPendingCancellableWillBeCancelledOnTimeout()
 
     public function testCancelTimeoutWithoutCancellationhandlerWillNotCancelTimerAndWillNotReject()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = new \React\Promise\Promise(function () { });
 
         $loop = $this->getMock('React\EventLoop\LoopInterface');
@@ -97,10 +89,6 @@ public function testCancelTimeoutWithoutCancellationhandlerWillNotCancelTimerAnd
 
     public function testCancelTimeoutWillCancelGivenPromise()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = new \React\Promise\Promise(function () { }, $this->expectCallableOnce());
 
         $timeout = Timer\timeout($promise, 0.01, $this->loop);
@@ -110,10 +98,6 @@ public function testCancelTimeoutWillCancelGivenPromise()
 
     public function testCancelGivenPromiseWillReject()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = new \React\Promise\Promise(function () { }, function ($resolve, $reject) { $reject(); });
 
         $timeout = Timer\timeout($promise, 0.01, $this->loop);
@@ -126,10 +110,6 @@ public function testCancelGivenPromiseWillReject()
 
     public function testCancelTimeoutWillRejectIfGivenPromiseWillReject()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = new \React\Promise\Promise(function () { }, function ($resolve, $reject) { $reject(); });
 
         $timeout = Timer\timeout($promise, 0.01, $this->loop);
@@ -142,10 +122,6 @@ public function testCancelTimeoutWillRejectIfGivenPromiseWillReject()
 
     public function testCancelTimeoutWillResolveIfGivenPromiseWillResolve()
     {
-        if (!interface_exists('React\Promise\CancellablePromiseInterface', true)) {
-            $this->markTestSkipped('Your (outdated?) Promise API does not support cancellable promises');
-        }
-
         $promise = new \React\Promise\Promise(function () { }, function ($resolve, $reject) { $resolve(); });
 
         $timeout = Timer\timeout($promise, 0.01, $this->loop);