fix: properly forward return urls where missing

tests/Controller/Traits/ReturnUrlTraitTest.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Controller\Traits;
+
+use App\Controller\Traits\ReturnUrlTrait;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\HttpFoundation\Request;
+
+class ReturnUrlTraitTest extends TestCase
+{
+    public const DEFAULT_ROUTE = 'app_administrative_teamer_index';
+    public const DEFAULT_URL = '/administrative/teamer';
+
+    private object $controller;
+
+    protected function setUp(): void
+    {
+        $this->controller = new class {
+            use ReturnUrlTrait;
+
+            /**
+             * @param array<string, mixed> $parameters
+             */
+            public function generateUrl(string $route, array $parameters = []): string
+            {
+                return ReturnUrlTraitTest::DEFAULT_URL.([] === $parameters ? '' : '?'.http_build_query($parameters));
+            }
+        };
+    }
+
+    public function testTheReturnUrlIsDecoded(): void
+    {
+        $request = Request::create('/somewhere?r='.rawurlencode('/administrative/teamer?page=3&sort=name'));
+
+        self::assertSame(
+            '/administrative/teamer?page=3&sort=name',
+            $this->controller->getReturnUrl($request, self::DEFAULT_ROUTE)
+        );
+    }
+
+    public function testAMissingParameterFallsBackToTheDefaultRoute(): void
+    {
+        $request = Request::create('/somewhere');
+
+        self::assertSame(self::DEFAULT_URL, $this->controller->getReturnUrl($request, self::DEFAULT_ROUTE));
+    }
+
+    /**
+     * A link forwarding a return url it never received itself emits "r=", which must
+     * not be read as a return url pointing at the root.
+     */
+    public function testAnEmptyParameterFallsBackToTheDefaultRoute(): void
+    {
+        $request = Request::create('/somewhere?r=');
+
+        self::assertSame(self::DEFAULT_URL, $this->controller->getReturnUrl($request, self::DEFAULT_ROUTE));
+    }
+
+    public function testTheDefaultRouteKeepsItsParameters(): void
+    {
+        $request = Request::create('/somewhere');
+
+        self::assertSame(
+            self::DEFAULT_URL.'?uuid=abc',
+            $this->controller->getReturnUrl($request, self::DEFAULT_ROUTE, ['uuid' => 'abc'])
+        );
+    }
+}

tests/Twig/ForwardedReturnUrlTest.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Twig;
+
+use App\Twig\AppRuntime;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+class ForwardedReturnUrlTest extends KernelTestCase
+{
+    private RequestStack $requestStack;
+    private AppRuntime $appRuntime;
+
+    protected function setUp(): void
+    {
+        self::bootKernel();
+
+        $this->requestStack = self::getContainer()->get(RequestStack::class);
+        $this->appRuntime = self::getContainer()->get(AppRuntime::class);
+    }
+
+    public function testTheReturnUrlIsPassedOnUntouched(): void
+    {
+        $encoded = rawurlencode('/administrative/assignment?page=3');
+        $this->requestStack->push(Request::create('/administrative/assignment/detail/abc?r='.$encoded));
+
+        // The raw query value, handed straight back to the url generator, which
+        // re-encodes it. No decoding of its own, that stays the consumer's job.
+        self::assertSame('/administrative/assignment?page=3', $this->appRuntime->getForwardedReturnUrl());
+    }
+
+    /**
+     * Null rather than an empty string, so the url generator drops the parameter
+     * instead of emitting "r=".
+     */
+    public function testNothingIsPassedOnWithoutAReturnUrl(): void
+    {
+        $this->requestStack->push(Request::create('/administrative/assignment/detail/abc'));
+
+        self::assertNull($this->appRuntime->getForwardedReturnUrl());
+    }
+
+    public function testNothingIsPassedOnForAnEmptyReturnUrl(): void
+    {
+        $this->requestStack->push(Request::create('/administrative/assignment/detail/abc?r='));
+
+        self::assertNull($this->appRuntime->getForwardedReturnUrl());
+    }
+}