CORS middleware with Zend Expressive

index.php

<?php

use Zend\Expressive\AppFactory;

require __DIR__ . "/../vendor/autoload.php;

$app = AppFactory::create();

$app->pipe(new \Tuupola\Middleware\Cors([
    "origin" => ["*"],
    "methods" => ["GET", "POST", "PUT", "PATCH", "DELETE"],
    "headers.allow" => ["Authorization", "If-Match", "If-Unmodified-Since"],
    "headers.expose" => ["Etag"],
    "credentials" => true,
    "cache" => 86400
]));

$app->get("/", function ($request, $response, $next) {
    $response->getBody()->write("Hello, world!");
    return $response;
});

$app->pipeRoutingMiddleware();
$app->pipeDispatchMiddleware();
$app->run();

result.txt

$ php -S 0.0.0.0:80 index.php
$ curl localhost:8080 --include --header "Origin: http://www.example.com"
HTTP/1.1 200 OK
Host: localhost:8080
Connection: close
X-Powered-By: PHP/5.6.17
Access-Control-Allow-Origin: http://www.example.com
Access-Control-Allow-Credentials: true
Vary: Origin
Access-Control-Expose-Headers: Etag
Content-Length: 13
Content-type: text/html; charset=UTF-8

Hello, world!