refactor: share callable param classification between router and dispatcher

Author: michalsn

system/CodeIgniter.php

@@ -31,6 +31,8 @@
 use CodeIgniter\HTTP\ResponsableInterface;
 use CodeIgniter\HTTP\ResponseInterface;
 use CodeIgniter\HTTP\URI;
+use CodeIgniter\Router\CallableParamClassifier;
+use CodeIgniter\Router\ParamKind;
 use CodeIgniter\Router\RouteCollectionInterface;
 use CodeIgniter\Router\Router;
 use Config\App;
@@ -727,36 +729,37 @@ private function resolveCallableParams(ReflectionFunctionAbstract $reflection, a
         $routeIndex = 0;
 
         foreach ($reflection->getParameters() as $param) {
-            // Inject FormRequest subclasses regardless of position.
-            $formRequestClass = FormRequest::getFormRequestClass($param);
-
-            if ($formRequestClass !== null) {
-                $resolved[] = $this->resolveFormRequest($formRequestClass);
-
-                continue;
-            }
-
-            // Variadic parameter - consume all remaining route segments.
-            if ($param->isVariadic()) {
-                while (array_key_exists($routeIndex, $routeParams)) {
-                    $resolved[] = $routeParams[$routeIndex++];
-                }
-
-                break;
-            }
-
-            // Consume the next route segment if one is available.
-            if (array_key_exists($routeIndex, $routeParams)) {
-                $resolved[] = $routeParams[$routeIndex++];
-
-                continue;
-            }
-
-            // No more route segments. Required params stop iteration so that
-            // PHP throws an ArgumentCountError on the call site. Optional
-            // params are omitted - PHP then applies their declared default value.
-            if (! $param->isOptional()) {
-                break;
+            [$kind, $formRequestClass] = CallableParamClassifier::classify($param);
+
+            switch ($kind) {
+                case ParamKind::FormRequest:
+                    // Inject FormRequest subclasses regardless of position.
+                    $resolved[] = $this->resolveFormRequest($formRequestClass);
+
+                    continue 2;
+
+                case ParamKind::Variadic:
+                    // Consume all remaining route segments.
+                    while (array_key_exists($routeIndex, $routeParams)) {
+                        $resolved[] = $routeParams[$routeIndex++];
+                    }
+                    break 2;
+
+                case ParamKind::Scalar:
+                    // Consume the next route segment if one is available.
+                    if (array_key_exists($routeIndex, $routeParams)) {
+                        $resolved[] = $routeParams[$routeIndex++];
+
+                        continue 2;
+                    }
+
+                    // No more route segments. Required params stop iteration so
+                    // that PHP throws an ArgumentCountError on the call site.
+                    // Optional params are omitted - PHP then applies their
+                    // declared default value.
+                    if (! $param->isOptional()) {
+                        break 2;
+                    }
             }
         }
 

system/Commands/Generators/Views/formrequest.tpl.php

@@ -21,7 +21,7 @@ public function rules(): array
     // /**
     //  * Custom error messages keyed by field.rule.
     //  *
-    //  * @return array<string, array<string, string>|string>
+    //  * @return array<string, array<string, string>>
     //  */
     // public function messages(): array
     // {

system/HTTP/FormRequest.php

@@ -74,7 +74,7 @@ abstract public function rules(): array;
      *      'title' => ['required' => 'Post title cannot be empty.'],
      *  ];
      *
-     * @return array<string, array<string, string>|string>
+     * @return array<string, array<string, string>>
      */
     public function messages(): array
     {

system/Router/AutoRouterImproved.php

@@ -14,7 +14,6 @@
 namespace CodeIgniter\Router;
 
 use CodeIgniter\Exceptions\PageNotFoundException;
-use CodeIgniter\HTTP\FormRequest;
 use CodeIgniter\Router\Exceptions\MethodNotFoundException;
 use Config\Routing;
 use ReflectionClass;
@@ -443,22 +442,24 @@ private function checkParameters(): void
             throw new MethodNotFoundException();
         }
 
-        // FormRequest parameters are injected by the framework and do not
-        // consume URI segments, so exclude them from the count.
-        $nonFormRequestParams = array_values(array_filter(
-            $refParams,
-            static fn ($p): bool => FormRequest::getFormRequestClass($p) === null,
-        ));
-
-        // A variadic parameter absorbs any number of trailing URI segments,
-        // so there is no upper bound to enforce.
-        foreach ($nonFormRequestParams as $p) {
-            if ($p->isVariadic()) {
+        // Count only parameters that consume one URI segment each. A variadic
+        // parameter absorbs any number of trailing segments, so there is no
+        // upper bound to enforce.
+        $scalarCount = 0;
+
+        foreach ($refParams as $param) {
+            [$kind] = CallableParamClassifier::classify($param);
+
+            if ($kind === ParamKind::Variadic) {
                 return;
             }
+
+            if ($kind === ParamKind::Scalar) {
+                $scalarCount++;
+            }
         }
 
-        if (count($nonFormRequestParams) < count($this->params)) {
+        if ($scalarCount < count($this->params)) {
             throw new PageNotFoundException(
                 'The param count in the URI are greater than the controller method params.'
                 . ' Handler:' . $this->controller . '::' . $this->method

system/Router/CallableParamClassifier.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Router;
+
+use CodeIgniter\HTTP\FormRequest;
+use ReflectionParameter;
+
+/**
+ * Single source of truth for how the auto-router and the dispatcher
+ * interpret a reflected callable parameter with respect to URI segment
+ * consumption. Keeps AutoRouterImproved::checkParameters() and
+ * CodeIgniter::resolveCallableParams() aligned on "FormRequest",
+ * "variadic", and "scalar URI consumer".
+ */
+final class CallableParamClassifier
+{
+    /**
+     * Returns the param kind and, when the kind is FormRequest, the resolved
+     * FormRequest class name so the caller does not need to re-inspect the
+     * parameter's type to inject it.
+     *
+     * @return array{ParamKind, class-string<FormRequest>|null}
+     */
+    public static function classify(ReflectionParameter $param): array
+    {
+        $formRequestClass = FormRequest::getFormRequestClass($param);
+
+        if ($formRequestClass !== null) {
+            return [ParamKind::FormRequest, $formRequestClass];
+        }
+
+        if ($param->isVariadic()) {
+            return [ParamKind::Variadic, null];
+        }
+
+        return [ParamKind::Scalar, null];
+    }
+}

system/Router/ParamKind.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <admin@codeigniter.com>
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Router;
+
+/**
+ * Classifies how a reflected callable parameter consumes URI segments
+ * during auto-routing and dispatch.
+ */
+enum ParamKind
+{
+    case FormRequest;
+    case Variadic;
+    case Scalar;
+}

tests/system/HTTP/FormRequestTest.php

@@ -359,7 +359,6 @@ public function testResolveRequestReturnsResponseOnInvalidData(): void
         $response = $formRequest->resolveRequest();
 
         $this->assertInstanceOf(ResponseInterface::class, $response);
-        $this->assertInstanceOf(ResponseInterface::class, $response);
     }
 
     public function testFailedValidationResponseContainsErrors(): void