behavior & specification driven development in php - #openwest
TRANSCRIPT
Behavior & Specification Driven Development in PHP
Presented by Joshua Warren
OR:
I heard you like to code, so let’s write code that writes code while
you code.
About Me
PHP DeveloperWorking with PHP since 1999
Founder & CEOFounded Creatuity in 2008
PHP Development Firm
Focused on the Magento platform
Tink, a Creatuity shareholder
JoshuaWarren.com
@JoshuaSWarren
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What You Need To Know
ASSUMPTIONS
Today we assume you’re a PHP developer.
That you are familiar with test driven development.
And that you’ve at least tried PHPUnit, Selenium or another testing tool.
BDD - no, the B does not stand for beer, despite what a Brit might tell you
Behavior Driven Development
Think of BDD as stepping back a level from TDD.
Graphic thanks to BugHuntress
TDD generally deals with functional units.
BDD steps back a level to consider complete features.
In BDD, you write feature files in the form of user stories that you test against.
BDD uses a ubiquitous language - basically, a language that business stakeholders, project managers, developers
and our automated tools can all understand.
Sample Behat Feature File
Feature: Laravel Test In order to demonstrate Laravel and Behat As a user I need to be able to visit the homepage of a new Laravel app Scenario: Homepage Given I am on the homepage Then I should see "Laravel 5"
Behat
We implement BDD in PHP with a tool called Behat
Behat is a free, open source tool designed for BDD and PHP
SpecBDD - aka, Testing Tongue Twisters
Specification Behavior Driven Development
Before you write a line of code, you write a specification for how that code should work
Focuses you on architectural decisions up-front
PHPSpec
Open Source tool for specification driven development in PHP
Why Use Behat and PHPSpec?
These tools allow you to focus exclusively on logic
Helps build functional testing coverage
Guides planning and ensuring that all stakeholders are in agreement
Let’s Build Something!
… what we’re building …
Setting up Our Project
Setup a Laravel 5 project
Run composer require —dev
behat/behat
behat/mink
behat/mink-extensions
laracasts/behat-laravel-extension
phpspec/phpspec
benconstable/phpspec-laravel
Run:
vendor/bin/behat —init
Create /behat.yaml
default: extensions: Laracasts\Behat: ~ Behat\MinkExtension\ServiceContainer\MinkExtension: default_session: laravel laravel: ~
Create /phpspec.yamlsuites:
main:
namespace: App
psr4_prefix: App
src_path: app
extensions:
- PhpSpec\Laravel\Extension\LaravelExtension
Features
features/fitbit.featureFeature: Fitbit IntegrationIn order to obtain Fitbit dataAs a userI need to be able to authenticate with Fitbit
Scenario: Not yet authenticated Given I am not logged in as “[email protected]” When I go to "/fitbit/" Then I should see "Please authenticate"
vendor/bin/behat —append-snippets
Scenario: Not yet authenticated:6 Given I am not logged in as “[email protected] When I go to "/fitbit/" Then I should see "Please authenticate" 1 scenario (1 undefined) 3 steps (1 undefined, 2 skipped) 0m0.48s (11.00Mb)
u features/bootstrap/FeatureContext.php - `I am not logged in as` definition added
Behat’s written code for us!
/features/bootstrap/FeatureContext.php
/** * @Given I am not logged in as :arg1 */public function iAmNotLoggedInAs($arg1){ throw new PendingException(); }
Behat writes just enough to get us show us where to add our logic.
Behat expects us to add logic to this function to detect the user is not logged in.
Before we do that, let’s finish out our feature file.
features/fitbit.feature continuedScenario: I have authenticatedGiven I am logged in as “[email protected]” When I go to "/fitbit/"Then I should see "Welcome back"
Scenario: I have sleep dataGiven I am logged in as “[email protected]” When I go to "/fitbit/sleep/"Then I should see "Sleep Report"
Run vendor/bin/behat —append-snippets one more time
Now, let’s fill in the logic Behat needs us to add.
/features/bootstrap/FeatureContext.php
/** * @Given I am not logged in as :email */public function iAmNotLoggedInAs($email) { // We completely log out // Destroy the previous session if (Session::isStarted()) { Session::regenerate(true); } else { Session::start(); } }
/features/bootstrap/FeatureContext.phppublic function iAmLoggedInAs($email) { // Destroy the previous session if (Session::isStarted()) { Session::regenerate(true); } else { Session::start(); } // Login the user and since the driver and this code now // share a session this will also login the driver session $user = User::where('email', $email)->firstOrFail(); Auth::login($user); // Save the session data to disk or to memcache Session::save(); // Hack for Selenium // Before setting a cookie the browser needs to be launched if ($this->getSession()->getDriver() instanceof \Behat\Mink\Driver\Selenium2Driver) { $this->visit('login'); } // Get the session identifier for the cookie $encryptedSessionId = Crypt::encrypt(Session::getId()); $cookieName = Session::getName(); // Set the cookie $minkSession = $this->getSession(); $minkSession->setCookie($cookieName, $encryptedSessionId); }
We run vendor/bin/behat once more
vendor/bin/behat…
Scenario: I have sleep data Given I am logged in as "[email protected]" When I go to "/fitbit/sleep/" Then I should see "Sleep Report" The text "Sleep Report" was not found anywhere in the text of the current page. (Behat\Mink\Exception\ResponseTextException)
--- Failed scenarios: features/fitbit.feature:6 features/fitbit.feature:11 features/fitbit.feature:16
A perfect failure!
These failures show us that Behat is testing our app properly, and now we just need to write the
application logic.
Specifications
Now we write specifications for how our Fitbit class should work.
These specifications should provide the logic to deliver the results that Behat is testing for.
vendor/bin/phpspec describe Fitbit
Specification for Fitbit created in <project root>/spec/FitbitSpec.php
PHPSpec generates a basic spec file for us
spec/FitbitSpec.phpnamespace spec; use PhpSpec\ObjectBehavior; use Prophecy\Argument; class FitbitSpec extends ObjectBehavior{ function it_is_initializable() { $this->shouldHaveType('Fitbit'); } }
This default spec tells PHPSpec to expect a class named Fitbit.
Now we add a bit more to the file so PHPSpec will understand what this class should do.
spec/FitbitSpec.php continuedfunction it_connects_to_fitbit($email) { $this->connect($email)->shouldReturn('Success'); } function it_returns_sleep_data($email) { $this->sleepData($email)->shouldReturn([8, 8, 8, 8, 8]); }
Now we run PHPSpec once more…
vendor/bin/phpspec run 10 ! is initializable (142ms) class Fitbit does not exist. 15 ! connects to fitbit (100ms) class Fitbit does not exist. 20 ! returns sleep data class Fitbit does not exist.
---- broken examples
Fitbit 10 ! is initializable (142ms) class Fitbit does not exist.
Fitbit 15 ! connects to fitbit (100ms) class Fitbit does not exist.
Fitbit 20 ! returns sleep data class Fitbit does not exist.
1 specs 3 examples (3 broken)
Lots of failures…
But wait a second - PHPSpec prompts us!
Do you want me to create `Fitbit` for you? [Y/n]
PHPSpec will create the class and the methods for us!
This is very powerful with frameworks like Laravel and Magento, which have PHPSpec plugins that help PHPSpec know where class files should be
located.
Fitbit.php - class Fitbit {
function connect($email) { // TODO: write logic here} function sleepData($email) { // TODO: write logic here}
And now, the easy part…
Implementation
Implement logic in the new Fitbit class in the locations directed by PHPSpec
Tie that logic into views in our application.
Once we’re done with the implementation, we move on to…
Testing
Once we’re done, running phpspec run should return green
Once phpspec returns green, run behat, which should return green as well
We now know that our new feature is working correctly without needing to open a web browser
PHPSpec gives us confidence that the application logic was implemented correctly.
Behat gives us confidence that the feature is being displayed properly to users.
Success!
The purpose of this talk is to get you hooked on Behat & PHPSpec and show you how easy it is to
get started.
Behat and PHPSpec are both powerful tools
PHPSpec can be used at a very granular level to ensure your application logic works correctly
Next week, setup Behat and PHPSpec on one of your projects and take it for a quick test by
implementing one short feature.
