Cache only the last getAllowedMethods() lookup

Slim/Routing/FastRouteDispatcher.php

@@ -15,7 +15,12 @@
 class FastRouteDispatcher extends GroupCountBased
 {
     /**
-     * @var string[][]
+     * @var string|null
+     */
+    private ?string $allowedMethodsUri = null;
+
+    /**
+     * @var string[]
      */
     private array $allowedMethods = [];
 
@@ -86,8 +91,8 @@ private function routingResults(string $httpMethod, string $uri): array
      */
     public function getAllowedMethods(string $uri): array
     {
-        if (isset($this->allowedMethods[$uri])) {
-            return $this->allowedMethods[$uri];
+        if ($this->allowedMethodsUri === $uri) {
+            return $this->allowedMethods;
         }
 
         $allowedMethods = [];
@@ -104,6 +109,8 @@ public function getAllowedMethods(string $uri): array
             }
         }
 
-        return $this->allowedMethods[$uri] = array_keys($allowedMethods);
+        $this->allowedMethodsUri = $uri;
+
+        return $this->allowedMethods = array_keys($allowedMethods);
     }
 }

tests/Routing/FastRouteDispatcherTest.php

@@ -107,6 +107,21 @@ public function testGetAllowedMethods($method, $uri, $callback, $allowedMethods)
         $this->assertSame($results, $allowedMethods);
     }
 
+    public function testGetAllowedMethodsReusesLastUriOnly()
+    {
+        /** @var FastRouteDispatcher $dispatcher */
+        $dispatcher = simpleDispatcher(function (RouteCollector $r) {
+            $r->addRoute('GET', '/user', 'handler0');
+            $r->addRoute('POST', '/post', 'handler1');
+        }, $this->generateDispatcherOptions());
+
+        $this->assertSame(['GET'], $dispatcher->getAllowedMethods('/user'));
+        $this->assertSame(['POST'], $dispatcher->getAllowedMethods('/post'));
+
+        // Repeating the first URI recomputes, as only the last result is kept.
+        $this->assertSame(['GET'], $dispatcher->getAllowedMethods('/user'));
+    }
+
     public function testDuplicateVariableNameError()
     {
         $this->expectException(BadRouteException::class);