Laravel HTTP client concurrent requests pool

concurrent-pool.php

<?php

// 1. Register the routes
Route::get('test/{lorem}', function ($lorem) {
    sleep(3);

    return response()->json([
        'message' => $lorem,
        'token' => Str::random(),
    ]);
});

// 2. Spin up 4 `php artisan serve` processes (they will get assigned from ports 8000..8003)

// 3. Register the macro

class PendingConcurrentPool
{
    private int $concurrency = 10;
    private Closure $requestsBuilder;

    public function __construct(Closure $requestsBuilder)
    {
        $this->requestsBuilder = $requestsBuilder;
    }

    public function concurrency(int $amount): self
    {
        $this->concurrency = $amount;
        return $this;
    }

    public function wait(): Collection
    {
        $responses = collect();

        $pool = new Pool(new Client(), call_user_func($this->requestsBuilder), [
            'concurrency' => $this->concurrency,
            'fulfilled' => function (Response $response, $index) use ($responses) {
                $responses[$index] = new \Illuminate\Http\Client\Response($response);
            },
            'rejected' => function (RequestException $reason, $index) use ($responses) {
                $responses[$index] = new \Illuminate\Http\Client\Response($reason->getResponse());
            },
        ]);

        $pool->promise()->wait();

        return $responses;
    }
}

PendingRequest::macro('pool', function (Closure $requestsBuilder) {
    return new PendingConcurrentPool($requestsBuilder);
});

// 4. Paste this in your tests/Feature/ExampleTest.php

public function testSendsConcurrentRequests()
{
    $responses = Http::pool(function () {
        return yield from [
            'req-1' => new Request('GET', 'http://localhost:8000/test/req-1'),
            'req-2' => new Request('GET', 'http://localhost:8001/test/req-2'),
            'req-3' => new Request('GET', 'http://localhost:8002/test/req-3'),
            'req-4' => new Request('GET', 'http://localhost:8003/test/req-4'),
        ];
    })->concurrency(4)->wait();

    dump($responses->map->json());
}

// 5. The output should be something like this:

/*
Illuminate\Support\Collection^ {#670
  #items: array:4 [
    "req-1" => array:2 [
      "message" => "req-1"
      "token" => "hJXWAcsTzauf0pgM"
    ]
    "req-2" => array:2 [
      "message" => "req-2"
      "token" => "plkQsQEiHDhLF90i"
    ]
    "req-3" => array:2 [
      "message" => "req-3"
      "token" => "g1nPymiH4ao1BNSb"
    ]
    "req-4" => array:2 [
      "message" => "req-4"
      "token" => "VB9UXvu7ekbJ1dEC"
    ]
  ]
}
*/

// Each request takes 3 seconds (see route, there is a sleep there), but since we
// are sending them all at once (we are sending 4 requests with a concurrency
// of 4), the total amount of time to send all 4 requests is 3 seconds.