Laravel: Finding the route name

Recently at work I had to analyze a problem in a Laravel application that I was not familiar with. The problem: When calling a specific URL, it wrongly redirected to another URL.

The route that I expected to be called was not, and routes/web.php was huge; too large to find the matching route quickly.

The solution was to adjust public/index.php and add the following line before the response was sent back to the browser:

$response->header('X-Route', Route::currentRouteName());
$response->send();

Now I could look at the redirect's HTTP headers to find the route that had been used:

$ curl -I http://app.example.org/en/explanatory-videos/test-510/
HTTP/1.1 302 Found
Date: Wed, 16 Sep 2020 11:45:26 GMT
Server: nginx/1.10.3 (Ubuntu)
Content-Type: text/html; charset=UTF-8
Cache-Control: no-cache, private
Location: http://app.example.org/en/products
X-Route: en_product_detail