Mocking Guzzle clients in behat

parameters:
    client_helper_class: AppBundle\Util\ClientHelper

parameters:
    client_helper_class: AppBundle\Features\Mock\ClientHelperMock

namespace AppBundle\Service;

use AppBundle\Util\ClientHelper;
use Symfony\Component\HttpFoundation\Request;

class PostcodeService
{
    private $client;
    private $apiUri;

    public function __construct(
        ClientHelper $client,
        $apiUri
    ) {
        $this->client = $client;
        $this->apiUri = $apiUri;
    }

    public function get($postcode)
    {
        return $this->client->request(Request::METHOD_GET, $this->apiUri.$postcode);
    }
}

service:
    app.service.postcode:
        class: AppBundle\Service\PostcodeService
        arguments:
            - "@app.util.client_helper"
            - "%postcodes_api%"

namespace AppBundle\Util;

use GuzzleHttp\ClientInterface;
use GuzzleHttp\Exception\ClientException;
use GuzzleHttp\Psr7\Response;
use GuzzleHttp\Psr7\Stream;

class ClientHelper
{
    private $client;

    public function __construct(ClientInterface $client)
    {
        $this->client = $client;
    }

    public function request($method, $uri, array $options = [])
    {
        $details = null;

        try {
            /** @var Response $response */
            $response = $this->client->request($method, $uri, $options);
            /** @var Stream $body */
            $body = $response->getBody();
            $details = $body->getContents();
        } catch (ClientException $e) {
        }

        return $details;
    }
}

services:
    app.util.client_helper:
        class: '%client_helper_class%'
        arguments:
            - '@app.util.guzzle'

    app.util.guzzle:
        class: GuzzleHttp\Client

namespace AppBundle\Features\Mock;

use AppBundle\Util\ClientHelper;

class ClientHelperMock extends ClientHelper
{
    public static $data;

    public function request($method, $uri, array $options = [])
    {
        $response = [];

        $position = strrpos($uri, '/');
        if ($position !== false) {
            $postcode = substr($uri, $position+1);

            if (isset(self::$data['postcode']) && self::$data['postcode'] == $postcode) {
                $response = self::$data['result'];
            }
        }

        return json_encode($response);
    }
}

/**
 * @param PyStringNode $stringNode
 *
 * @Given /^the Postcode API is available with data:$/
 */
public function thePostcodeApiIsAvailableWith(PyStringNode $stringNode)
{
    ClientHelperMock::$data = json_decode($stringNode->getRaw(), true);
}

Feature: Getting postcode details.
  In order to get postcode details
  As a user
  I should be able call call external API

  Scenario: I get empty result for non-existent postcode.
    Given the Postcode API is available with data:
    """
    {"postcode":"POSTCODE 1","result":{"longitude":-0.11111111,"latitude":0.11111111}}
    """
    When I send a "GET" request to "/postcodes/NON-EXISTENT POSTCODE"
    Then the response status code should be 200
    And the response should contain json:
    """
    []
    """

  Scenario: I get full result for existent postcode.
    Given the Postcode API is available with data:
    """
    {"postcode":"POSTCODE 1","result":{"longitude":-0.11111111,"latitude":0.11111111}}
    """
    When I send a "GET" request to "/postcodes/POSTCODE 1"
    Then the response status code should be 200
    And the response should contain json:
    """
    {"longitude":-0.11111111,"latitude":0.11111111}
    """

$ vendor/bin/behat --suite=app src/AppBundle/Features/Postcode.feature
Feature: Getting postcode details.
  In order to get postcode details
  As a user
  I should be able call call external API

  Scenario: I get empty result for non-existent postcode.
    Given the Postcode API is available with data:
      """
      {"postcode":"POSTCODE 1","result":{"longitude":-0.11111111,"latitude":0.11111111}}
      """
    When I send a "GET" request to "/postcodes/NON-EXISTENT POSTCODE"
    Then the response status code should be 200
    And the response should contain json:
      """
      []
      """

  Scenario: I get full result for existent postcode.
    Given the Postcode API is available with data:
      """
      {"postcode":"POSTCODE 1","result":{"longitude":-0.11111111,"latitude":0.11111111}}
      """
    When I send a "GET" request to "/postcodes/POSTCODE 1"
    Then the response status code should be 200
    And the response should contain json:
      """
      {"longitude":-0.11111111,"latitude":0.11111111}
      """
      
2 scenarios (2 passed)
8 steps (8 passed)
0m1.24s (30.72Mb)