Behat is a Behavioral Driven Development test framework for PHP. The power of Behat, and BDD in general, is that your tests define how your application should behave in different scenarios. More than just confirming that parts of your application work, BDD helps define and clarify the overall design of your application. And since Behat/BDD tests are written in plain English, they can be understood by devs, managers, marketers, and everyone else involved with your application.
Get set up
- Install Composer
First, make sure you have PHP Dependency Manager Composer installed. Follow the instructions on their download page to install it.
- Install Behat
Once you have Composer, the easiest way to get set up would be to clone this repository, then run
composer installto install the modules listed in composer.json (and their dependencies). - Set up conf.yml files
In order to run any tests, you will need to make a few changes to the configuration files located in config/.
In order to run tests, you’ll need valid credentials, so set user to the email address associated with your CrossBrowserTesting account, and set
keyto your authkey. The easiest way to find your authkey by going to your account page.You can also change your
capabilitiesandbrowerskeys to rename/re-version your test, extend themax_duration, or change your target browser(s).To find the os_api_name and browser_api_name that corresponds to your targeted platform, you can go to CrossBrowserTesting’s Selenium Page, open the wizard, and watch the capabilities in the sample script change as you select different browsers, or you can parse the os/browser you want out of the JSON response from https://crossbrowsertesting.com/api/v3/selenium/browsers.
Write tests
Now that the environment is set up, we can start actually writing tests. There are two main steps to writing test with Behat: define application behavior as scenarios and steps, then code each step as a function.
Define behavior in *.feature files
Accurately and concisely describing application behavior is the core of BDD. Behat (and most other BDD frameworks) use the Gherkin language to write real automated tests in plain English.
Let’s walk through writing a couple simple tests for our example login page. It’s a simple page, so our tests will not be very long.
Let’s start by defining what our feature is in features/login.feature
As a user
I should be able to log in
If I supply valid user credentials
Simple enough. The whole block will be displayed at the start of the test, so make sure that it says something useful.
Next, we define how our application should behave in different scenarios. For this simple login page there are only two scenarios we need to test: a valid login, and an invalid login.
Given I go to "http://crossbrowsertesting.github.io/login-form.html"
When I fill in "#username" with "[email protected]"
And I fill in "#password" with "badpassword"
And I press ".form-actions > button"
Then I should see ".alert-danger" say "Username or password is incorrect"
Scenario: Login with good credentials
Given I go to "http://crossbrowsertesting.github.io/login-form.html"
When I fill in "#username" with "[email protected]"
And I fill in "#password" with "test123"
And I press ".form-actions > button"
Then I should see "#logged-in-message>p" say "You are now logged in!"
As you can see, we use plain english to describe the setup (being on the right page), the actions for the test (filling in username and password then clicking the login button), and the desired outcome (the message we see).
The Gherkin language can handle some very complicated test logic, so I recommend taking a look at Behat’s official guide to writing features with Gherkin.
Coding steps in the FeatureContext.php file
Now that our feature is defined, we can run our tests with $ bin/behat.
You should see an output like this:
10 steps (10 undefined)
0m0.011s
You can implement step definitions for undefined steps with these snippets:
/**
* @Given /^I go to "([^"]*)"$/
*/
public function iGoTo($arg1)
{
throw new PendingException();
}
[...]
So, we can see that Behat parsed login.feature but was not able to find functions in features/bootstrap/FeatureContext.php to tell it how to execute each step.
But we can copy the functions it generates and paste them into our FeatureContext.php file to give us a starting place.
The comment above each function describes the Regex that it uses to link steps in the login.feature file to the function, as well as how arguments get passed from the step to the function.
Now we just have to write some Selenium code to define each step!
Run tests
Now that everything is set up, let us try running the test!
Feature: Test a login form
Scenario: Login with bad credentials # /Users/johnreese/Google Drive/CBT/repos/behat-browserstack/features/single/login.feature:3
Given I go to "http://crossbrowsertesting.github.io/login-form.html"# FeatureContext::iGoTo()
When I fill in "#username" with "[email protected]"# FeatureContext::iFillInWith()
And I fill in "#password" with "badpassword"# FeatureContext::iFillInWith()
And I press ".form-actions > button"# FeatureContext::iPress()
Then I should see ".alert-danger" say "Username or password is incorrect" # FeatureContext::iShouldSeeSay()
Scenario: Login with good credentials # /Users/johnreese/Google Drive/CBT/repos/behat-browserstack/features/single/login.feature:10
Given I go to "http://crossbrowsertesting.github.io/login-form.html"# FeatureContext::iGoTo()
When I fill in "#username" with "[email protected]"# FeatureContext::iFillInWith()
And I fill in "#password" with "test123"# FeatureContext::iFillInWith()
And I press ".form-actions > button"# FeatureContext::iPress()
Then I should see "#logged-in-message>p" say "You are now logged in!"# FeatureContext::iShouldSeeSay()
2 scenarios (2 passed)
10 steps (10 passed)
0m43.527s
Success!
For examples and source code to this tutorial, check out our Behat GitHub Repository.
See Also
Test Frameworks and Tools
About Selenium Testing
Selenium and PHP
CodeCeption