guzzle/tests/RetryMiddlewareTest.php

<?php
namespace GuzzleHttp\Tests;

use GuzzleHttp\Client;
use GuzzleHttp\Handler\MockHandler;
use GuzzleHttp\Middleware;
use GuzzleHttp\Psr7;
use GuzzleHttp\Psr7\Request;
use GuzzleHttp\Psr7\Response;
use GuzzleHttp\RetryMiddleware;
use PHPUnit\Framework\TestCase;

class RetryMiddlewareTest extends TestCase
{
    public function testRetriesWhenDeciderReturnsTrue()
    {
        $delayCalls = 0;
        $calls = [];
        $decider = function ($retries, $request, $response, $error) use (&$calls) {
            $calls[] = func_get_args();
            return count($calls) < 3;
        };
        $delay = function ($retries, $response) use (&$delayCalls) {
            $delayCalls++;
            $this->assertEquals($retries, $delayCalls);
            $this->assertInstanceOf(Response::class, $response);
            return 1;
        };
        $m = Middleware::retry($decider, $delay);
        $h = new MockHandler([new Response(200), new Response(201), new Response(202)]);
        $f = $m($h);
        $c = new Client(['handler' => $f]);
        $p = $c->sendAsync(new Request('GET', 'http://test.com'), []);
        $p->wait();
        $this->assertCount(3, $calls);
        $this->assertEquals(2, $delayCalls);
        $this->assertEquals(202, $p->wait()->getStatusCode());
    }

    public function testDoesNotRetryWhenDeciderReturnsFalse()
    {
        $decider = function () { return false; };
        $m = Middleware::retry($decider);
        $h = new MockHandler([new Response(200)]);
        $c = new Client(['handler' => $m($h)]);
        $p = $c->sendAsync(new Request('GET', 'http://test.com'), []);
        $this->assertEquals(200, $p->wait()->getStatusCode());
    }

    public function testCanRetryExceptions()
    {
        $calls = [];
        $decider = function ($retries, $request, $response, $error) use (&$calls) {
            $calls[] = func_get_args();
            return $error instanceof \Exception;
        };
        $m = Middleware::retry($decider);
        $h = new MockHandler([new \Exception(), new Response(201)]);
        $c = new Client(['handler' => $m($h)]);
        $p = $c->sendAsync(new Request('GET', 'http://test.com'), []);
        $this->assertEquals(201, $p->wait()->getStatusCode());
        $this->assertCount(2, $calls);
        $this->assertEquals(0, $calls[0][0]);
        $this->assertNull($calls[0][2]);
        $this->assertInstanceOf('Exception', $calls[0][3]);
        $this->assertEquals(1, $calls[1][0]);
        $this->assertInstanceOf(Response::class, $calls[1][2]);
        $this->assertNull($calls[1][3]);
    }

    public function testBackoffCalculateDelay()
    {
        $this->assertEquals(0, RetryMiddleware::exponentialDelay(0));
        $this->assertEquals(1, RetryMiddleware::exponentialDelay(1));
        $this->assertEquals(2, RetryMiddleware::exponentialDelay(2));
        $this->assertEquals(4, RetryMiddleware::exponentialDelay(3));
        $this->assertEquals(8, RetryMiddleware::exponentialDelay(4));
    }
}