amp/test/DeferredTest.php

<?php

namespace Amp\Test;

use Amp\Deferred;
use Amp\Promise;

class DeferredTest extends \PHPUnit\Framework\TestCase {
    /** @var \Amp\Deferred */
    private $deferred;

    public function setUp() {
        $this->deferred = new Deferred;
    }

    public function testGetPromise() {
        $promise = $this->deferred->promise();
        $this->assertInstanceOf(Promise::class, $promise);
    }

    /**
     * @depends testGetPromise
     */
    public function testResolve() {
        $value = "Resolution value";
        $promise = $this->deferred->promise();

        $invoked = false;
        $promise->when(function ($exception, $value) use (&$invoked, &$result) {
            $invoked = true;
            $result = $value;
        });

        $this->deferred->resolve($value);

        $this->assertTrue($invoked);
        $this->assertSame($value, $result);
    }

    /**
     * @depends testGetPromise
     */
    public function testFail() {
        $exception = new \Exception;
        $promise = $this->deferred->promise();

        $invoked = false;
        $promise->when(function ($exception, $value) use (&$invoked, &$result) {
            $invoked = true;
            $result = $exception;
        });

        $this->deferred->fail($exception);

        $this->assertTrue($invoked);
        $this->assertSame($exception, $result);
    }
}