fix(router): content-type json support when mapping psr request to tempest request (#956)

Author: brendt

src/Tempest/Router/src/Mappers/PsrRequestToRequestMapper.php

@@ -13,6 +13,7 @@
 use Tempest\Router\Upload;
 use Tempest\Validation\Validator;
 use function Tempest\map;
+use function Tempest\Support\arr;
 
 final readonly class PsrRequestToRequestMapper implements Mapper
 {
@@ -33,6 +34,14 @@ public function map(mixed $from, mixed $to): array|object
 
         $data = (array) $from->getParsedBody();
 
+        if (arr($from->getHeader('content-type'))->contains('application/json')) {
+            $bodyContents = $from->getBody()->getContents();
+
+            if (json_validate($bodyContents)) {
+                $data = [...$data, ...json_decode($bodyContents, true)];
+            }
+        }
+
         $headersAsString = array_map(
             fn (array $items) => implode(',', $items),
             $from->getHeaders(),

tests/Fixtures/Controllers/JsonController.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Tests\Tempest\Fixtures\Controllers;
+
+use Tempest\Router\Post;
+use Tempest\Router\Request;
+use Tempest\Router\Responses\Ok;
+
+final class JsonController
+{
+    #[Post('/json-endpoint')]
+    public function __invoke(Request $request)
+    {
+        return new Ok($request->get('title'));
+    }
+}

tests/Integration/Route/RouterTest.php

@@ -4,6 +4,9 @@
 
 namespace Tests\Tempest\Integration\Route;
 
+use Laminas\Diactoros\ServerRequest;
+use Laminas\Diactoros\Stream;
+use Laminas\Diactoros\Uri;
 use Tempest\Core\AppConfig;
 use Tempest\Database\Migrations\CreateMigrationsTable;
 use Tempest\Http\Status;
@@ -188,4 +191,21 @@ public function test_uri_with_query_param_that_collides_partially_with_route_par
             uri([UriGeneratorController::class, 'withCollidingNames'], id: '1', idea: 'hi'),
         );
     }
+
+    public function test_json_request(): void
+    {
+        $router = $this->container->get(Router::class);
+
+        $response = $router->dispatch(new ServerRequest(
+            uri: new Uri('/json-endpoint'),
+            method: 'POST',
+            body: new Stream(fopen(__DIR__ . '/request.json', 'r')),
+            headers: [
+                'Content-Type' => 'application/json',
+            ],
+        ));
+
+        $this->assertSame(Status::OK, $response->status);
+        $this->assertSame('foo', $response->body);
+    }
 }

tests/Integration/Route/request.json

@@ -0,0 +1 @@
+{"title":  "foo"}