myep-team/tests/MyEp/Api/AccessTokenProviderTest.php

<?php

namespace App\Tests\MyEp\Api;

use App\MyEp\Api\AccessTokenProvider;
use App\MyEp\Api\ApiException;
use PHPUnit\Framework\TestCase;
use Psr\Cache\CacheItemPoolInterface;
use Psr\Log\NullLogger;
use Symfony\Component\Cache\Adapter\ArrayAdapter;
use Symfony\Component\HttpClient\MockHttpClient;
use Symfony\Component\HttpClient\Response\MockResponse;

class AccessTokenProviderTest extends TestCase
{
    private const CACHE_KEY = 'myep.api.access_token';

    public function testTokenIsReturnedFromTheTokenEndpoint(): void
    {
        $httpClient = new MockHttpClient([$this->tokenResponse('abc123')]);

        $this->assertEquals('abc123', $this->getProviderInstance($httpClient)->getToken());
    }

    public function testTheClientCredentialsGrantIsRequested(): void
    {
        $body = null;
        $httpClient = new MockHttpClient(function (string $method, string $url, array $options) use (&$body) {
            $this->assertEquals('POST', $method);
            $this->assertEquals('https://myep.example/token', $url);
            $body = $options['body'];

            return $this->tokenResponse('abc123');
        });

        $this->getProviderInstance($httpClient)->getToken();

        $this->assertStringContainsString('grant_type=client_credentials', $body);
        $this->assertStringContainsString('scope=api', $body);
        $this->assertStringContainsString('client_secret=secret', $body);
    }

    public function testTheTokenIsCachedRatherThanRequestedPerCall(): void
    {
        $httpClient = new MockHttpClient([$this->tokenResponse('abc123')]);
        $cache = new ArrayAdapter();
        $provider = $this->getProviderInstance($httpClient, $cache);

        $provider->getToken();
        $provider->getToken();

        $this->assertEquals(1, $httpClient->getRequestsCount());
        $this->assertTrue($cache->getItem(self::CACHE_KEY)->isHit());
    }

    public function testACachedTokenIsUsedWithoutAskingForANewOne(): void
    {
        $cache = new ArrayAdapter();
        $item = $cache->getItem(self::CACHE_KEY);
        $item->set('cached-token');
        $cache->save($item);

        $httpClient = new MockHttpClient([]);

        $this->assertEquals('cached-token', $this->getProviderInstance($httpClient, $cache)->getToken());
        $this->assertEquals(0, $httpClient->getRequestsCount());
    }

    public function testAnInvalidatedTokenIsRequestedAgain(): void
    {
        $httpClient = new MockHttpClient([$this->tokenResponse('abc123'), $this->tokenResponse('def456')]);
        $provider = $this->getProviderInstance($httpClient);

        $provider->getToken();
        $provider->invalidate();

        $this->assertEquals('def456', $provider->getToken());
        $this->assertEquals(2, $httpClient->getRequestsCount());
    }

    public function testARejectedRequestFails(): void
    {
        $httpClient = new MockHttpClient([
            new MockResponse('{"error":"invalid_client"}', ['http_code' => 401]),
        ]);

        $this->expectException(ApiException::class);

        $this->getProviderInstance($httpClient)->getToken();
    }

    public function testAResponseWithoutATokenFails(): void
    {
        $httpClient = new MockHttpClient([new MockResponse('{"expires_in":600}')]);

        $this->expectException(ApiException::class);

        $this->getProviderInstance($httpClient)->getToken();
    }

    public function testAnUnreachableTokenEndpointFails(): void
    {
        $httpClient = new MockHttpClient([new MockResponse('', ['error' => 'connection refused'])]);

        $this->expectException(ApiException::class);

        $this->getProviderInstance($httpClient)->getToken();
    }

    public function testAnUnparsableResponseFails(): void
    {
        $httpClient = new MockHttpClient([new MockResponse('<html>gateway timeout</html>')]);

        $this->expectException(ApiException::class);

        $this->getProviderInstance($httpClient)->getToken();
    }

    private function tokenResponse(string $token, int $expiresIn = 600): MockResponse
    {
        return new MockResponse(json_encode([
            'access_token' => $token,
            'token_type' => 'Bearer',
            'expires_in' => $expiresIn,
        ]));
    }

    private function getProviderInstance(MockHttpClient $httpClient, ?CacheItemPoolInterface $cache = null): AccessTokenProvider
    {
        return new AccessTokenProvider(
            $httpClient,
            $cache ?? new ArrayAdapter(),
            new NullLogger(),
            [
                'client_id' => 'team-app',
                'client_secret' => 'secret',
                'token_path' => 'https://myep.example/token',
                'scope' => 'api',
            ],
        );
    }
}