symfony · fabpot · Mar 4, 2019 · Feb 27, 2019
diff --git a/UPGRADE-4.3.md b/UPGRADE-4.3.md
@@ -37,6 +37,7 @@ FrameworkBundle
 * Not passing the project directory to the constructor of the `AssetsInstallCommand` is deprecated. This argument will
   be mandatory in 5.0.
 * Deprecated the "Psr\SimpleCache\CacheInterface" / "cache.app.simple" service, use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead.
+ * The `generate()` method of the `UrlGenerator` class can return an empty string instead of null.

 HttpFoundation
 --------------

diff --git a/src/Symfony/Component/Routing/Generator/ConfigurableRequirementsInterface.php b/src/Symfony/Component/Routing/Generator/ConfigurableRequirementsInterface.php
@@ -20,7 +20,7 @@
 * The possible configurations and use-cases:
 * - setStrictRequirements(true): Throw an exception for mismatching requirements. This
 *   is mostly useful in development environment.
- * - setStrictRequirements(false): Don't throw an exception but return null as URL for
+ * - setStrictRequirements(false): Don't throw an exception but return an empty string as URL for
 *   mismatching requirements and log the problem. Useful when you cannot control all
 *   params because they come from third party libs but don't want to have a 404 in
 *   production environment. It should log the mismatch so one can review it.

diff --git a/src/Symfony/Component/Routing/Generator/UrlGenerator.php b/src/Symfony/Component/Routing/Generator/UrlGenerator.php
@@ -171,7 +171,7 @@ protected function doGenerate($variables, $defaults, $requirements, $tokens, $pa
                            $this->logger->error($message, ['parameter' => $varName, 'route' => $name, 'expected' => $token[2], 'given' => $mergedParams[$varName]]);
                        }

-                        return;
+                        return '';
                    }

                    $url = $token[1].$mergedParams[$varName].$url;
@@ -226,7 +226,7 @@ protected function doGenerate($variables, $defaults, $requirements, $tokens, $pa
                            $this->logger->error($message, ['parameter' => $token[3], 'route' => $name, 'expected' => $token[2], 'given' => $mergedParams[$token[3]]]);
                        }

-                        return;
+                        return '';
                    }

                    $routeHost = $token[1].$mergedParams[$token[3]].$routeHost;

diff --git a/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php b/src/Symfony/Component/Routing/Tests/Generator/UrlGeneratorTest.php
@@ -203,7 +203,7 @@ public function testGenerateForRouteWithInvalidOptionalParameterNonStrict()
        $routes = $this->getRoutes('test', new Route('/testing/{foo}', ['foo' => '1'], ['foo' => 'd+']));
        $generator = $this->getGenerator($routes);
        $generator->setStrictRequirements(false);
-        $this->assertNull($generator->generate('test', ['foo' => 'bar'], UrlGeneratorInterface::ABSOLUTE_URL));
+        $this->assertSame('', $generator->generate('test', ['foo' => 'bar'], UrlGeneratorInterface::ABSOLUTE_URL));
    }

    public function testGenerateForRouteWithInvalidOptionalParameterNonStrictWithLogger()
@@ -214,7 +214,7 @@ public function testGenerateForRouteWithInvalidOptionalParameterNonStrictWithLog
            ->method('error');
        $generator = $this->getGenerator($routes, [], $logger);
        $generator->setStrictRequirements(false);
-        $this->assertNull($generator->generate('test', ['foo' => 'bar'], UrlGeneratorInterface::ABSOLUTE_URL));
+        $this->assertSame('', $generator->generate('test', ['foo' => 'bar'], UrlGeneratorInterface::ABSOLUTE_URL));
    }

    public function testGenerateForRouteWithInvalidParameterButDisabledRequirementsCheck()
@@ -489,7 +489,7 @@ public function testUrlWithInvalidParameterInHostInNonStrictMode()
        $routes = $this->getRoutes('test', new Route('/', [], ['foo' => 'bar'], [], '{foo}.example.com'));
        $generator = $this->getGenerator($routes);
        $generator->setStrictRequirements(false);
-        $this->assertNull($generator->generate('test', ['foo' => 'baz'], UrlGeneratorInterface::ABSOLUTE_PATH));
+        $this->assertSame('', $generator->generate('test', ['foo' => 'baz'], UrlGeneratorInterface::ABSOLUTE_PATH));
    }

    public function testHostIsCaseInsensitive()