Add ContentLengthMiddleware

Author: devanych

src/Middleware/ContentLengthMiddleware.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace HttpSoft\Basis\Middleware;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+final class ContentLengthMiddleware implements MiddlewareInterface
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        $response = $handler->handle($request);
+        $size = $response->getBody()->getSize();
+
+        if ($size !== null && !$response->hasHeader('content-length')) {
+            $response = $response->withHeader('content-length', (string) $size);
+        }
+
+        return $response;
+    }
+}

tests/Middleware/ContentLengthMiddlewareTest.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace HttpSoft\Tests\Basis\Middleware;
+
+use HttpSoft\Basis\Middleware\ContentLengthMiddleware;
+use HttpSoft\Message\Response;
+use HttpSoft\Message\ServerRequest;
+use PHPUnit\Framework\TestCase;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+class ContentLengthMiddlewareTest extends TestCase
+{
+    public function testProcess(): void
+    {
+        $middleware = new ContentLengthMiddleware();
+        $response = $middleware->process(new ServerRequest(), new class implements RequestHandlerInterface {
+            public function handle(ServerRequestInterface $request): ResponseInterface
+            {
+                $response = new Response();
+                $response->getBody()->write('Content');
+                return $response;
+            }
+        });
+        $this->assertSame(7, $response->getBody()->getSize());
+        $this->assertSame('7', $response->getHeaderLine('content-length'));
+    }
+}