Extending the extension

If you want to implement your own assertions, or for instance add custom authentication for all requests made against your APIs you can extend the context class provided by the extension to access the client, request, request options, response and the array contains comparator properties. These properties are accessed via the protected $this->client, $this->request, $this->requestOptions, $this->response and $this->arrayContainsComparator properties respectively. Keep in mind that $this->response is not populated until the client has made a request, i.e. after any of the aforementioned @When steps have finished.

Add @Given‘s, @When‘s and/or @Then‘s

If you want to add a @Given, @When and/or @Then step, simply add a method in your FeatureContext class along with the step using annotations in the phpdoc block:

<?php
use Imbo\BehatApiExtension\Context\ApiContext;
use Imbo\BehatApiExtension\Exception\AssertionFailedException as Failure;

class FeatureContext extends ApiContext {
    /**
     * @Then I want to check something
     */
    public function assertSomething() {
        // do some assertions on $this->response, and throw a Failure exception is the
        // assertion fails.
    }
}

With the above example you can now use Then I want to check something can be used in your feature files along with the steps defined by the extension.

Manipulate the API client

If you wish to manipulate the API client (GuzzleHttp\Client) this can be done in the initialization-phase:

<?php
use Imbo\BehatApiExtension\Context\ApiContext;
use GuzzleHttp\ClientInterface;
use GuzzleHttp\Middleware;
use Psr\Http\Message\RequestInterface;

class FeatureContext extends ApiContext {
    /**
     * Manipulate the API client
     *
     * @param ClientInterface $client
     * @return self
     */
    public function setClient(ClientInterface $client) {
        $stack = $client->getConfig('handler');
        $stack->push(Middleware::mapRequest(function(RequestInterface $request) {
            // Add something to the request and return the new instance
            return $request->withAddedHeader('Some-Custom-Header', 'some value');
        }));

        return parent::setClient($client);
    }
}

Register custom matcher functions

The extension comes with some built in matcher functions used to verify JSON-content (see Then the response body contains JSON: <PyStringNode>), like for instance @arrayLength and @regExp. These functions are basically callbacks to PHP methods / functions, so you can easily define your own and use them in your tests:

<?php
use Imbo\BehatApiExtension\Context\ApiContext;
use Imbo\BehatApiExtension\ArrayContainsComparator;

class FeatureContext extends ApiContext {
    /**
     * Add a custom function called @gt to the comparator
     *
     * @param ArrayContainsComparator $comparator
     * @return self
     */
    public function setArrayContainsComparator(ArrayContainsComparator $comparator) {
        $comparator->addFunction('gt', function($num, $gt) {
            $num = (int) $num;
            $gt = (int) $gt;

            if ($num <= $gt) {
                throw new InvalidArgumentException(sprintf(
                    'Expected number to be greater than %d, got: %d.',
                    $gt,
                    $num
                ));
            }
        });

        return parent::setArrayContainsComparator($comparator);
    }
}

The above snippet adds a custom matcher function called @gt that can be used to check if a number is greater than another number. Given the following response body:

{
  "number": 42
}

the number in the number key could be verified with:

Then the response body contains JSON:
    """
    {
      "number": "@gt(40)"
    }
    """