Testing WebServices

The same way we tested a web site, Codeception allows you to test web services. They are very hard to test manually, so it's really good idea to automate web service testing. As a standards we have SOAP and REST, which are represented in corresponding modules. We will cover them in this chapter.

You should start with creating a new test suite, which was not provided by the bootstrap command. We recommend to call it api and use the ApiTester class for it.

$ php codecept.phar generate:suite api

We will put all the api tests there.

REST

The REST web service is accessed via HTTP with standard methods: GET, POST, PUT, DELETE. They allow to receive and manipulate entities from the service. Accessing WebService requires HTTP client, so for using it you need the module PhpBrowser or one of framework modules set up. For example, we can use the Symfony2 module for Symfony2 applications in order to ignore web server and test web service internally.

Configure modules in api.suite.yml:

class_name: ApiTester
modules:
    enabled:
      - REST:
          url: http://serviceapp/api/v1/
          depends: PhpBrowser

The REST module will connect to PhpBrowser according to this configuration. Depending on web service we may deal with XML or JSON responses. Codeception handles both data formats well, however If you don't need one of them, you can explicitly specify that the JSON or XML parts of the module will be used:

class_name: ApiTester
modules:
    enabled:
      - REST:
          url: http://serviceapp/api/v1/
          depends: PhpBrowser
          part: Json

API tests can be functional and be executed using Symfony2, Laravel4, Laravel5, Zend, or any other framework module. You will need slightly update configuration for it:

class_name: ApiTester
modules:
    enabled:
      - REST:
          url: /api/v1/
          depends: Laravel5

Once we configured new testing suite, we can create the first sample test:

$ php codecept.phar generate:cept api CreateUser

It will be called CreateUserCept.php. We can use it to test creation of a user via the REST API.

<?php
$I = new ApiTester($scenario);
$I->wantTo('create a user via API');
$I->amHttpAuthenticated('service_user', '123456');
$I->haveHttpHeader('Content-Type', 'application/x-www-form-urlencoded');
$I->sendPOST('/users', ['name' => 'davert', 'email' => 'davert@codeception.com']);
$I->seeResponseCodeIs(200);
$I->seeResponseIsJson();
$I->seeResponseContains('{"result":"ok"}');
?>

Testing JSON Responses

The latest line checked that the response contained the provided string. However we shouldn't rely on it, as depending on content formatting we can receive different results with the same data. What we actually need is to check that the response can be parsed and it contains some of the values we expect. In the case of JSON we can use seeResponseContainsJson method

<?php
// matches {"result":"ok"}'
$I->seeResponseContainsJson(['result' => 'ok']);
// it can match tree-like structures as well
$I->seeResponseContainsJson([
    'user' => [
            'name' => 'davert',
            'email' => 'davert@codeception.com',
            'status' => 'inactive'
    ]
]);
?>

You may want to perform even more complex assertions on a response. This can be done by writing your own methods in Helper classes. To access the latest JSON response you will need to get the response property of the REST module. Let's demonstrate it with seeResponseIsHtml method:

<?php
namespace Helper;
class Api extends \Codeception\Module
{
    public function seeResponseIsHtml()
    {
        $response = $this->getModule('REST')->response;
        \PHPUnit_Framework_Assert::assertRegex('~^<!DOCTYPE HTML(.*?)<html>.*?<\/html>~m', $response);
    }
}
?>

The same way you can receive request parameters and headers.

Validate JSON structures

It is pretty common for API tests to not only validate the received data but to check the structure of the response. Response data is not usually considered to be consistent, and may change on each request, however the JSON/XML structure should be kept the same for an API version. In order to check response structure the REST module has some useful methods.

If we expect a JSON response to be received we can check its structure with JSONPath. It looks and sounds like XPath but is designed to work with JSON data, however we can convert JSON into XML and use XPath to validate the structure. Both approaches are valid and can be used in the REST module:

<?php
$I = new ApiTester($scenario);
$I->wantTo('validate structure of GitHub api responses');
$I->sendGET('/users');
$I->seeResponseIsJson();
$I->seeResponseJsonMatchesJsonPath('$[0].user.login');
$I->seeResponseJsonMatchesXpath('//user/login');
?>

Testing XML Responses

In case your REST API works with XML format you can use similar methods to test its data and structure. There is seeXmlResponseIncludes method to match inclusion of XML parts in response, and seeXmlResponseMatchesXpath to validate its structure.

<?php
use Codeception\Util\Xml as XmlUtils;

$I = new ApiTester($scenario);
$I->wantTo('validate structure of GitHub api responses');
$I->sendGET('/users.xml');
$I->seeResponseIsXml();
$I->seeXmlResponseMatchesXpath('//user/login');
$I->seeXmlResponseIncludes(XmlUtils::toXml(
        'user' => [
            'name' => 'davert',
            'email' => 'davert@codeception.com',
            'status' => 'inactive'
    ]
));
?>

We are using XmlUtils class which allows us to build XML structures in a clean manner. The toXml method may accept a string or array and returns \DOMDocument instance. If your XML contains attributes and so can't be represented as a PHP array you can create XML using the XmlBulder class. We will take a look at it a bit more in next section.

Use `\Codeception\Util\Xml::build()` to create XmlBuilder instance.

SOAP

SOAP web services are usually more complex. You will need PHP configured with SOAP support. Good knowledge of XML is required too. SOAP module uses specially formatted POST request to connect to WSDL web services. Codeception uses PhpBrowser or one of framework modules to perform interactions. If you choose using a framework module, SOAP will automatically connect to the underlying framework. That may improve the speed of a test execution and will provide you with more detailed stack traces.

Let's configure SOAP module to be used with PhpBrowser:

class_name: ApiTester
modules:
    enabled:
      - SOAP:
          depends: PhpBrowser
          endpoint: http://serviceapp/api/v1/

SOAP request may contain application specific information, like authentication or payment. This information is provided with SOAP header inside the <soap:Header> element of XML request. In case you need to submit such header, you can use haveSoapHeader action. For example, next line of code

<?php
$I->haveSoapHeader('Auth', array('username' => 'Miles', 'password' => '123456'));
?>

will produce this XML header

<soap:Header>
<Auth>
    <username>Miles</username>
    <password>123456</password>
</Auth>
</soap:Header>

Use sendSoapRequest method to define the body of your request.

<?php
$I->sendSoapRequest('CreateUser', '<name>Miles Davis</name><email>miles@davis.com</email>');
?>

This call will be translated to XML:

<soap:Body>
<ns:CreateUser>
    <name>Miles Davis</name>
    <email>miles@davis.com</email>
</ns:CreateUser>
</soap:Body>

And here is the list of sample assertions that can be used with SOAP.

<?php
$I->seeSoapResponseEquals('<?xml version="1.0"?><error>500</error>');
$I->seeSoapResponseIncludes('<result>1</result>');
$I->seeSoapResponseContainsStructure('<user><name></name><email></email>');
$I->seeSoapResponseContainsXPath('//result/user/name[@id=1]');
?>

In case you don't want to write long XML strings, consider using XmlBuilder class. It will help you to build complex XMLs in jQuery-like style. In the next example we will use XmlBuilder instead of regular XML.

<?php
use \Codeception\Util\Xml;

$I = new ApiTester($scenario);
$I->wantTo('create user');
$I->haveSoapHeader('Session', array('token' => '123456'));
$I->sendSoapRequest('CreateUser', Xml::build()
    ->user->email->val('miles@davis.com'));
$I->seeSoapResponseIncludes(Xml::build()
    ->result->val('Ok')
        ->user->attr('id', 1)
);
?>

It's up to you to decide whether to use XmlBuilder or plain XML. XmlBuilder will return XML string as well.

You may extend current functionality by using SOAP module in your helper class. To access the SOAP response as \DOMDocument you can use response property of SOAP module.

<?php
namespace Helper;
class Api extends \Codeception\Module {

    public function seeResponseIsValidOnSchema($schema)
    {
        $response = $this->getModule('SOAP')->response;
        $this->assertTrue($response->schemaValidate($schema));
    }
}
?>

Conclusion

Codeception has two modules that will help you to test various web services. They need a new api suite to be created. Remember, you are not limited to test only response body. By including Db module you may check if a user has been created after the CreateUser call. You can improve testing scenarios by using REST or SOAP responses in your helper methods.