Last days I’ve playing with Behat. Behat is a behavior driven development (BDD) framework based on Ruby’s Cucumber. Basically with Behat we defenie features within one feature file. I’m not going to crate a Behat tutorial (you can read more about Behat here). Behat use Gherkin to write the features files. When I was playing with Behat I had one idea. The idea is simple: Can we use Gherking to build a Silex application?. It was a good excuse to study Gherking, indeed ;).

Here comes the feature file:

Feature: application API Scenario: List users Given url "/api/users/list.json" And request method is "GET" Then instance "\Api\Users" And execute function "listUsers" And format output into json Scenario: Get user info Given url "/api/user/{userName}.json" And request method is "GET" Then instance "\Api\User" And execute function "info" And format output into json Scenario: Update user information Given url "/api/user/{userName}.json" And request method is "POST" Then instance "\Api\User" And execute function "update" And format output into json

Our API use this simple library:

<?php namespace Api; use Symfony\Component\HttpFoundation\Request; class User { private $request; public function __construct(Request $request) { $this->request = $request; } public function info() { switch ($this->request->get('userName')) { case 'gonzalo': return array('name' => 'Gonzalo', 'surname' => 'Ayuso'); case 'peter': return array('name' => 'Peter', 'surname' => 'Parker'); } } public function update() { return array('infoUpdated'); } }

<?php namespace Api; use Symfony\Component\HttpFoundation\Request; class Users { public function listUsers() { return array('gonzalo', 'peter'); } }

The idea is simple. Parse the feature file with behat/gherkin component and create a silex application. And here comes the “magic”. This is a simple working prototype, just an experiment for a rainy sunday.

<?php include __DIR__ . '/../vendor/autoload.php'; define(FEATURE_PATH, __DIR__ . '/api.feature'); use Behat\Gherkin\Lexer, Behat\Gherkin\Parser, Behat\Gherkin\Keywords\ArrayKeywords, Behat\Gherkin\Node\FeatureNode, Behat\Gherkin\Node\ScenarioNode, Symfony\Component\HttpFoundation\Request, Silex\Application; $keywords = new ArrayKeywords([ 'en' => [ 'feature' => 'Feature', 'background' => 'Background', 'scenario' => 'Scenario', 'scenario_outline' => 'Scenario Outline', 'examples' => 'Examples', 'given' => 'Given', 'when' => 'When', 'then' => 'Then', 'and' => 'And', 'but' => 'But' ], ]); function getMatch($subject, $pattern) { preg_match($pattern, $subject, $matches); return isset($matches[1]) ? $matches[1] : NULL; } $app = new Application(); function getScenarioConf($scenario) { $silexConfItem = []; /** @var $scenario ScenarioNode */ foreach ($scenario->getSteps() as $step) { $route = getMatch($step->getText(), '/^url "([^"]*)"$/'); if (!is_null($route)) { $silexConfItem['route'] = $route; } $requestMethod = getMatch($step->getText(), '/^request method is "([^"]*)"$/'); if (!is_null($requestMethod)) { $silexConfItem['requestMethod'] = strtoupper($requestMethod); } $instance = getMatch($step->getText(), '/^instance "([^"]*)"$/'); if (!is_null($instance)) { $silexConfItem['className'] = $instance; } $method = getMatch($step->getText(), '/^execute function "([^"]*)"$/'); if (!is_null($method)) { $silexConfItem['method'] = $method; } if ($step->getText() == 'format output into json') { $silexConfItem['jsonEncode'] = TRUE; } } return $silexConfItem; } /** @var $features FeatureNode */ $features = (new Parser(new Lexer($keywords)))->parse(file_get_contents(FEATURE_PATH), FEATURE_PATH); foreach ($features->getScenarios() as $scenario) { $silexConfItem = getScenarioConf($scenario); $app->match($silexConfItem['route'], function (Request $request) use ($app, $silexConfItem) { function getConstructorParams($rClass, $request) { $parameters =[]; foreach ($rClass->getMethod('__construct')->getParameters() as $parameter) { if ('Symfony\Component\HttpFoundation\Request' == $parameter->getClass()->name) { $parameters[$parameter->getName()] = $request; } } return $parameters; } $rClass = new ReflectionClass($silexConfItem['className']); $obj = ($rClass->hasMethod('__construct')) ? $rClass->newInstanceArgs(getConstructorParams($rClass, $request)) : new $silexConfItem['className']; $output = $obj->{$silexConfItem['method']}(); return ($silexConfItem['jsonEncode'] === TRUE) ? $app->json($output, 200) : $output; } )->method($silexConfItem['requestMethod']); } $app->run();

You can see the source code in github. What do you think?