bug #17744 Improve error reporting in router panel of web profiler (javiereguiluz)

This PR was squashed before being merged into the 2.7 branch (closes #17744).

Discussion
----------

Improve error reporting in router panel of web profiler

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #17342
| License       | MIT
| Doc PR        | -

### Problem

If you define a route condition like this:

```yaml
app:
    resource: '@AppBundle/Controller/'
    type:     annotation
    condition: "request.server.get('HTTP_HOST') matches '/.*\.dev/'"
```

When browsing the Routing panel in the web profiler, you see an exception:

![problem](https://cloud.githubusercontent.com/assets/73419/12930027/553eeb08-cf76-11e5-90b1-ab0de6175d4e.png)

#### Why?

Because the route condition uses the `request` object, but the special `TraceableUrlMatcher` class doesn't get access to the real `request` object but to the special object obtained via:

```php
$request = $profile->getCollector('request');
```

These are the contents of this pseudo-request:

![cause](https://cloud.githubusercontent.com/assets/73419/12930052/804ea248-cf76-11e5-9c38-2e43e1654065.png)

`request.server.get(...)` condition fails because `request.server` is `null`. The full exception message shows this:

![exception](https://cloud.githubusercontent.com/assets/73419/12930079/9c7d6058-cf76-11e5-8eeb-45f5059c824c.png)

### Solution

I propose to catch all exceptions in `TraceableUrlMatcher` and display an error message with some details of the exception:

![error_message](https://cloud.githubusercontent.com/assets/73419/12930106/b29e31d2-cf76-11e5-868c-98d8b0cc4e5b.png)

Commits
-------

1001554 Improve error reporting in router panel of web profiler

src/Symfony/Bundle/WebProfilerBundle/Controller/RouterController.php

@@ -18,6 +18,7 @@ use Symfony\Component\Routing\RouteCollection;
 use Symfony\Component\Routing\RouterInterface;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\HttpKernel\Profiler\Profiler;
+use Symfony\Component\HttpKernel\DataCollector\RequestDataCollector;
 
 /**
  * RouterController.
@@ -62,16 +63,39 @@ class RouterController
 
         $profile = $this->profiler->loadProfile($token);
 
-        $context = $this->matcher->getContext();
-        $context->setMethod($profile->getMethod());
-        $matcher = new TraceableUrlMatcher($this->routes, $context);
-
+        /** @var RequestDataCollector $request */
         $request = $profile->getCollector('request');
 
         return new Response($this->twig->render('@WebProfiler/Router/panel.html.twig', array(
             'request' => $request,
             'router' => $profile->getCollector('router'),
-            'traces' => $matcher->getTraces($request->getPathInfo()),
+            'traces' => $this->getTraces($request, $profile->getMethod()),
         )), 200, array('Content-Type' => 'text/html'));
     }
+
+    /**
+     * Returns the routing traces associated to the given request.
+     *
+     * @param RequestDataCollector $request
+     * @param string               $method
+     *
+     * @return array
+     */
+    private function getTraces(RequestDataCollector $request, $method)
+    {
+        $traceRequest = Request::create(
+            $request->getPathInfo(),
+            $request->getRequestServer()->get('REQUEST_METHOD'),
+            $request->getRequestAttributes()->all(),
+            $request->getRequestCookies()->all(),
+            array(),
+            $request->getRequestServer()->all()
+        );
+
+        $context = $this->matcher->getContext();
+        $context->setMethod($method);
+        $matcher = new TraceableUrlMatcher($this->routes, $context);
+
+        return $matcher->getTracesForRequest($traceRequest);
+    }
 }

src/Symfony/Component/Routing/Matcher/TraceableUrlMatcher.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Routing\Matcher;
 
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Exception\ExceptionInterface;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\Routing\RouteCollection;
@@ -40,6 +41,15 @@ class TraceableUrlMatcher extends UrlMatcher
         return $this->traces;
     }
 
+    public function getTracesForRequest(Request $request)
+    {
+        $this->request = $request;
+        $traces = $this->getTraces($request->getPathInfo());
+        $this->request = null;
+
+        return $traces;
+    }
+
     protected function matchCollection($pathinfo, RouteCollection $routes)
     {
         foreach ($routes as $name => $route) {

src/Symfony/Component/Routing/Tests/Matcher/TraceableUrlMatcherTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Routing\Tests\Matcher;
 
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\Routing\RouteCollection;
 use Symfony\Component\Routing\RequestContext;
@@ -98,4 +99,23 @@ class TraceableUrlMatcherTest extends \PHPUnit_Framework_TestCase
 
         return $levels;
     }
+
+    public function testRoutesWithConditions()
+    {
+        $routes = new RouteCollection();
+        $routes->add('foo', new Route('/foo', array(), array(), array(), 'baz', array(), array(), "request.headers.get('User-Agent') matches '/firefox/i'"));
+
+        $context = new RequestContext();
+        $context->setHost('baz');
+
+        $matcher = new TraceableUrlMatcher($routes, $context);
+
+        $notMatchingRequest = Request::create('/foo', 'GET');
+        $traces = $matcher->getTracesForRequest($notMatchingRequest);
+        $this->assertEquals("Condition \"request.headers.get('User-Agent') matches '/firefox/i'\" does not evaluate to \"true\"", $traces[0]['log']);
+
+        $matchingRequest = Request::create('/foo', 'GET', array(), array(), array(), array('HTTP_USER_AGENT' => 'Firefox'));
+        $traces = $matcher->getTracesForRequest($matchingRequest);
+        $this->assertEquals('Route matches!', $traces[0]['log']);
+    }
 }