Behat

Applies to CrossBrowserTesting SaaS, last modified on July 07, 2021

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 install to 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 key to your authkey. The easiest way to find your authkey by going to your account page.

    You can also change your capabilities and browers keys to rename/re-version your test, extend the max_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

Feature: Login to page
    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.

Scenario: Login with bad credentials
    Given I go to "http://crossbrowsertesting.github.io/login-form.html"
    When I fill in "#username" with "badusername@crossbrowsertesting.com"
    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 "tester@crossbrowsertesting.com"
    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:

2 scenarios (2 undefined)
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!

$ bin/behat -c config/single.conf.yml

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 "badusername@crossbrowsertesting.com"# 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 "tester@crossbrowsertesting.com"# 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

Highlight search results