[PHP] Add support for async requests

[ackintosh]

closes #5306

PR checklist

• Read the contribution guidelines.
• Ran the shell/batch script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates)
• Filed the PR against the correct branch: master for non-breaking changes and 2.3.0 branch for breaking (non-backward compatible) changes.

Description of the PR

(details of the change, additional tests that have been done, reference to the issue for tracking, etc)

Async requests

• xxxAsync
• xxxAsyncWithHttpInfo

Usage

$promise = $api->getPeByIdtAsyncWithHttpInfo(1)->then(function ($response) {
    var_dump($response);
    // array(3) {
    //   [0] =>
    //   class Swagger\Client\Model\Pet
    //   [1] =>
    //   int(200)
    //   [2] =>
    //   array(7) {
    //     'Date' =>
    // ...
}, function ($exception) {
    var_dump($exception);
    // class Swagger\Client\ApiException
});

var_dump($promise);
// class GuzzleHttp\Promise\Promise

$promise->wait();

[wing328]

@ackintosh thanks for the enhancement.

cc @baartosz @dkarlovi @arnested

[baartosz]

Looks good and works fine. Exceptions are working as expected.

Please just tweak @return type annotations.

[baartosz]

PromiseInterface is returned here, annotation is wrong

[baartosz]

it returns \GuzzleHttp\Promise\PromiseInterface

[baartosz]

@wing328 tag 2.2.3 is probably wrong as this branch depends on guzzle which is in 2.3.0 only

[wing328]

@baartosz already labelled as 2.3.0. Can you check again?

[baartosz]

@wing328 Sorry, I was thinking about milestone but wrote tag instead:
@wing328 wing328 modified the milestone: v2.3.0, v2.2.3 2 days ago
it looks like mistake for me.

[wing328]

@baartosz no worry and thanks for reviewing the change.

[ackintosh]

@baartosz Thanks for your comment ✨ I fixed it.

[baartosz]

@ackintosh I wrote some tests for this feature yesterday, please add them to this PR. Or I'll create another PR later.

samples/client/petstore/php/SwaggerClient-php/tests/AsyncTest.php:

<?php

namespace Swagger\Client;

use Swagger\Client\Api\PetApi;
use Swagger\Client\Model\Pet;

class AsyncTest extends \PHPUnit_Framework_TestCase
{
    /** @var PetApi */
    private $api;

    /** @var  int */
    private $petId;

    public function setUp()
    {
        $this->api = new Api\PetApi();

        $this->petId = 10005;
        $pet = new Model\Pet;
        $pet->setId($this->petId);
        $pet->setName("PHP Unit Test");
        $pet->setPhotoUrls(array("http://test_php_unit_test.com"));
        // new tag
        $tag= new Model\Tag;
        $tag->setId($this->petId); // use the same id as pet
        $tag->setName("test php tag");
        // new category
        $category = new Model\Category;
        $category->setId($this->petId); // use the same id as pet
        $category->setName("test php category");

        $pet->setTags(array($tag));
        $pet->setCategory($category);

        $pet_api = new Api\PetApi();
        // add a new pet (model)
        $add_response = $pet_api->addPet($pet);
    }

    public function testAsyncRequest()
    {
        $promise = $this->api->getPetByIdAsync(10005);

        $promise2 = $this->api->getPetByIdAsync(10005);

        $pet = $promise->wait();
        $pet2 = $promise2->wait();
        $this->assertInstanceOf(Pet::class, $pet);
        $this->assertInstanceOf(Pet::class, $pet2);
    }

    public function testAsyncRequestWithHttpInfo()
    {
        $promise = $this->api->getPetByIdAsyncWithHttpInfo($this->petId);

        list($pet, $status, $headers) = $promise->wait();
        $this->assertEquals(200, $status);
        $this->assertInternalType('array', $headers);
        $this->assertInstanceOf(Pet::class, $pet);
    }

    public function testAsyncThrowingException()
    {
        $this->setExpectedException(ApiException::class);

        $promise = $this->api->getPetByIdAsync(0);
        $promise->wait();
    }

    public function testAsyncApiExceptionWithoutWaitIsNotThrown()
    {
        $promise = $this->api->getPetByIdAsync(0);
        sleep(1);
    }

    public function testAsyncHttpInfoThrowingException()
    {
        $this->setExpectedException(ApiException::class);

        $promise = $this->api->getPetByIdAsyncWithHttpInfo(0);
        $promise->wait();
    }
}

[wing328]

@ackintosh thanks for the PR, which has been merged into master.

@baartosz thanks for reviewing the change and adding the test cases to cover the change.