Merge branch 'feature/type-safety'

Close #2

Author: weierophinney

CHANGELOG.md

@@ -2,15 +2,19 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 1.0.1 - TBD
+## 1.0.1 - 2018-02-21
 
 ### Added
 
 - Nothing.
 
 ### Changed
 
-- Nothing.
+- [#2](https://github.com/zendframework/zend-httphandlerrunner/pull/2) modifies
+  how the request and error response factories are composed with the
+  `RequestHandlerRunner` class. In both cases, they are now encapsulated in a
+  closure which also defines a return type hint, ensuring that if the factories
+  produce an invalid return type, a PHP `TypeError` will be raised.
 
 ### Deprecated
 

src/RequestHandlerRunner.php

@@ -9,6 +9,7 @@
 
 namespace Zend\HttpHandlerRunner;
 
+use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\RequestHandlerInterface;
 use Throwable;
@@ -66,8 +67,16 @@ public function __construct(
     ) {
         $this->handler = $handler;
         $this->emitter = $emitter;
-        $this->serverRequestFactory = $serverRequestFactory;
-        $this->serverRequestErrorResponseGenerator = $serverRequestErrorResponseGenerator;
+
+        // Factories are cast as Closures to ensure return type safety.
+        $this->serverRequestFactory = function () use ($serverRequestFactory) : ServerRequestInterface {
+            return $serverRequestFactory();
+        };
+
+        $this->serverRequestErrorResponseGenerator =
+            function (Throwable $exception) use ($serverRequestErrorResponseGenerator) : ResponseInterface {
+                return $serverRequestErrorResponseGenerator($exception);
+            };
     }
 
     /**

test/RequestHandlerRunnerTest.php

@@ -13,6 +13,8 @@
 use PHPUnit\Framework\Assert;
 use PHPUnit\Framework\TestCase;
 use Prophecy\Argument;
+use Throwable;
+use TypeError;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\RequestHandlerInterface;
@@ -80,4 +82,60 @@ public function testRunPassesRequestGeneratedByRequestFactoryToHandleWhenNoReque
 
         $this->assertNull($runner->run());
     }
+
+    public function testRaisesTypeErrorIfServerRequestFactoryDoesNotReturnARequestInstance()
+    {
+        $serverRequestFactory = function () {
+            return null;
+        };
+
+        $response = $this->prophesize(ResponseInterface::class)->reveal();
+        $errorResponseGenerator = function (Throwable $e) use ($response) {
+            Assert::assertInstanceOf(TypeError::class, $e);
+            return $response;
+        };
+
+        $handler = $this->prophesize(RequestHandlerInterface::class);
+        $handler->handle(Argument::any())->shouldNotBeCalled();
+
+        $emitter = $this->prophesize(EmitterInterface::class);
+        $emitter->emit($response)->shouldBeCalled();
+
+        $runner = new RequestHandlerRunner(
+            $handler->reveal(),
+            $emitter->reveal(),
+            $serverRequestFactory,
+            $errorResponseGenerator
+        );
+
+        $this->assertNull($runner->run());
+    }
+
+    public function testRaisesTypeErrorIfServerErrorResponseGeneratorFactoryDoesNotReturnAResponse()
+    {
+        $serverRequestFactory = function () {
+            return null;
+        };
+
+        $errorResponseGenerator = function (Throwable $e) {
+            Assert::assertInstanceOf(TypeError::class, $e);
+            return null;
+        };
+
+        $handler = $this->prophesize(RequestHandlerInterface::class);
+        $handler->handle(Argument::any())->shouldNotBeCalled();
+
+        $emitter = $this->prophesize(EmitterInterface::class);
+        $emitter->emit(Argument::any())->shouldNotBeCalled();
+
+        $runner = new RequestHandlerRunner(
+            $handler->reveal(),
+            $emitter->reveal(),
+            $serverRequestFactory,
+            $errorResponseGenerator
+        );
+
+        $this->expectException(TypeError::class);
+        $runner->run();
+    }
 }