Improved Exception management to be more specific

module/Core/src/Action/PreviewAction.php

@@ -7,8 +7,10 @@ use Interop\Http\ServerMiddleware\DelegateInterface;
 use Interop\Http\ServerMiddleware\MiddlewareInterface;
 use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
+use Shlinkio\Shlink\Common\Exception\PreviewGenerationException;
 use Shlinkio\Shlink\Common\Service\PreviewGeneratorInterface;
 use Shlinkio\Shlink\Common\Util\ResponseUtilsTrait;
+use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Service\UrlShortenerInterface;
 
@@ -46,14 +48,14 @@ class PreviewAction implements MiddlewareInterface
 
         try {
             $url = $this->urlShortener->shortCodeToUrl($shortCode);
-            if (! isset($url)) {
-                return $delegate->process($request);
-            }
-
             $imagePath = $this->previewGenerator->generatePreview($url);
             return $this->generateImageResponse($imagePath);
         } catch (InvalidShortCodeException $e) {
             return $delegate->process($request);
+        } catch (EntityDoesNotExistException $e) {
+            return $delegate->process($request);
+        } catch (PreviewGenerationException $e) {
+            return $delegate->process($request);
         }
     }
 }

module/Core/src/Action/QrCodeAction.php

@@ -11,6 +11,7 @@ use Psr\Http\Message\ServerRequestInterface as Request;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
 use Shlinkio\Shlink\Common\Response\QrCodeResponse;
+use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Service\UrlShortenerInterface;
 use Zend\Expressive\Router\RouterInterface;
@@ -55,12 +56,12 @@ class QrCodeAction implements MiddlewareInterface
         $shortCode = $request->getAttribute('shortCode');
         try {
             $shortUrl = $this->urlShortener->shortCodeToUrl($shortCode);
-            if ($shortUrl === null) {
-                return $delegate->process($request);
-            }
         } catch (InvalidShortCodeException $e) {
             $this->logger->warning('Tried to create a QR code with an invalid short code' . PHP_EOL . $e);
             return $delegate->process($request);
+        } catch (EntityDoesNotExistException $e) {
+            $this->logger->warning('Tried to create a QR code with a not found short code' . PHP_EOL . $e);
+            return $delegate->process($request);
         }
 
         $path = $this->router->generateUri('long-url-redirect', ['shortCode' => $shortCode]);

module/Core/src/Action/RedirectAction.php

@@ -9,8 +9,11 @@ use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
+use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
+use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Service\UrlShortenerInterface;
 use Shlinkio\Shlink\Core\Service\VisitsTrackerInterface;
+use Zend\Diactoros\Response\HtmlResponse;
 use Zend\Diactoros\Response\RedirectResponse;
 
 class RedirectAction implements MiddlewareInterface
@@ -66,9 +69,9 @@ class RedirectAction implements MiddlewareInterface
             // Return a redirect response to the long URL.
             // Use a temporary redirect to make sure browsers always hit the server for analytics purposes
             return new RedirectResponse($longUrl);
-        } catch (\Exception $e) {
-            // In case of error, dispatch 404 error
-            $this->logger->error('Error redirecting to long URL.' . PHP_EOL . $e);
+        } catch (InvalidShortCodeException $e) {
+            return $delegate->process($request);
+        } catch (EntityDoesNotExistException $e) {
             return $delegate->process($request);
         }
     }

module/Core/src/Service/UrlShortener.php

@@ -11,6 +11,7 @@ use GuzzleHttp\Exception\GuzzleException;
 use Psr\Http\Message\UriInterface;
 use Shlinkio\Shlink\Common\Exception\RuntimeException;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Exception\InvalidUrlException;
 use Shlinkio\Shlink\Core\Util\TagManagerTrait;
@@ -142,10 +143,11 @@ class UrlShortener implements UrlShortenerInterface
      * Tries to find the mapped URL for provided short code. Returns null if not found
      *
      * @param string $shortCode
-     * @return string|null
+     * @return string
      * @throws InvalidShortCodeException
+     * @throws EntityDoesNotExistException
      */
-    public function shortCodeToUrl($shortCode)
+    public function shortCodeToUrl($shortCode): string
     {
         $cacheKey = sprintf('%s_longUrl', $shortCode);
         // Check if the short code => URL map is already cached
@@ -158,17 +160,16 @@ class UrlShortener implements UrlShortenerInterface
             throw InvalidShortCodeException::fromCharset($shortCode, $this->chars);
         }
 
-        /** @var ShortUrl $shortUrl */
-        $shortUrl = $this->em->getRepository(ShortUrl::class)->findOneBy([
-            'shortCode' => $shortCode,
-        ]);
-        // Cache the shortcode
-        if (isset($shortUrl)) {
-            $url = $shortUrl->getOriginalUrl();
-            $this->cache->save($cacheKey, $url);
-            return $url;
+        $criteria = ['shortCode' => $shortCode];
+        /** @var ShortUrl|null $shortUrl */
+        $shortUrl = $this->em->getRepository(ShortUrl::class)->findOneBy($criteria);
+        if ($shortUrl === null) {
+            throw EntityDoesNotExistException::createFromEntityAndConditions(ShortUrl::class, $criteria);
         }
 
-        return null;
+        // Cache the shortcode
+        $url = $shortUrl->getOriginalUrl();
+        $this->cache->save($cacheKey, $url);
+        return $url;
     }
 }

module/Core/src/Service/UrlShortenerInterface.php

@@ -5,6 +5,7 @@ namespace Shlinkio\Shlink\Core\Service;
 
 use Psr\Http\Message\UriInterface;
 use Shlinkio\Shlink\Common\Exception\RuntimeException;
+use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Exception\InvalidUrlException;
 
@@ -25,8 +26,9 @@ interface UrlShortenerInterface
      * Tries to find the mapped URL for provided short code. Returns null if not found
      *
      * @param string $shortCode
-     * @return string|null
+     * @return string
      * @throws InvalidShortCodeException
+     * @throws EntityDoesNotExistException
      */
-    public function shortCodeToUrl($shortCode);
+    public function shortCodeToUrl($shortCode): string;
 }