How to implement Behat into your PHP project

Remember Joseph? 

The talented web developer who took off on a journey to embrace Behavior-Driven Development and Behat?

 

Well, he's back with even more insights to share!

In our previous blog post, we witnessed Joseph's transformation as he integrated Behavior-Driven Development into his freelance project for a spice-selling business.

 

The results were outstanding, with improved collaboration, clear objectives, and a more successful outcome.

Now, it's time to dig deeper into the nitty-gritty details of implementing Behat in PHP projects.

 

In this post, we'll walk you through setting up the project structure, crafting feature files using the expressive Gherkin syntax, and writing powerful step definitions in PHP.

By the end of this article, you'll have a solid grasp of how to leverage Behat to create robust and reliable tests for your PHP projects.

 

We'll also explore practical examples, share tips and tricks, and help you become a Behat ninja.

 

Understanding Behat Features

Behat is a powerful testing framework that brings Behavior-Driven Development to life.

 

It offers a wide range of features that make it a go-to tool for implementing BDD in PHP projects.

Let's dive into some of its key features and see how they can revolutionize your testing process.

 

One fundamental concept in Behat is the notion of "features."

Features represent the behavior or functionality you want to test in your application.

 

They are written in Gherkin, a human-readable language that uses a structured format to describe scenarios.

By expressing your tests in this way, you can ensure clear communication and collaboration between developers, testers, and stakeholders.

 

To organize and share test state and context across your scenarios, Behat provides the Context class.

This class acts as a container for the state and behavior of your application during testing.

 

It allows you to define and manipulate test data, interact with your application's components, and perform various actions required for testing.

The Context class plays a vital role in maintaining the consistency and integrity of your tests.

 

Another valuable feature of Behat is the SnippetAcceptingContext class.

When you write your feature files, you may encounter scenarios or steps that don't have corresponding step definitions.

 

Behat helps you address this issue by generating missing step definitions for you.

The SnippetAcceptingContext class is responsible for accepting these generated snippets and incorporating them into your test suite.

 

It saves you time and effort by automatically generating the skeleton code for the missing step definitions, allowing you to focus on writing the actual implementation.

 

Implementing Behat in Your PHP Project

To implement Behat in your PHP project, follow these basic steps:

 

1. Set up the directory structure:

Start by creating a dedicated directory within your PHP project to hold your Behat tests.

This structure will help you organize your tests effectively and keep them separate from your application code.

 

2. Define feature files with Gherkin syntax:

Feature files use Gherkin syntax to describe test scenarios in a human-readable format.

Each feature file represents a specific feature or functionality of your application.

 

Write descriptive scenarios using keywords like `Given`, `When`, and `Then` to define the steps and expected outcomes of your tests.

 

Here's an example of a feature file for the e-commerce application that sells spices that Joseph was working on in the previous part of this series.

 

Feature: Spice Ordering
  Scenario: Adding a spice to the cart
    Given I am on the spice catalog page
    When I click on the "Add to Cart" button for "Chili Powder"
    Then the spice should be added to the cart

 

3. Write step definitions in PHP:

Step definitions bridge the gap between your feature files and the actual code implementation.

 

In this step, you'll write PHP code that maps to the steps defined in your feature files.

Each step definition represents an action or verification that corresponds to a Gherkin step.

 

Implement the desired behavior within the step definitions to simulate user interactions, make assertions, and interact with your application.

use Behat\Behat\Context\Context;

class SpiceOrderingContext implements Context
{
    /**
     * @Given I am on the spice catalog page
     */
    public function iAmOnTheSpiceCatalogPage()
    {
        // Code to navigate to the spice catalog page
    }

    /**
     * @When I click on the :buttonName button for :spiceName
     */
    public function iClickOnTheButtonForSpice($buttonName, $spiceName)
    {
        // Code to click on the specified button for the given spice
    }

    /**
     * @Then the spice should be added to the cart
     */
    public function theSpiceShouldBeAddedToTheCart()
    {
        // Code to verify that the spice has been added to the cart
    }
}

 

By following these steps, you can integrate Behat into your PHP project and start writing BDD tests using Gherkin syntax and PHP step definitions.

This approach allows you to define test scenarios in a human-readable format and map them to the actual behavior of your application.

 

Handling Exceptions in Behat

When using Behat for testing, handling exceptions is an important aspect to consider.

Behat provides a useful feature called `PendingException` that allows you to mark steps as pending and skip their execution.

 

This can be helpful when you're in the process of implementing step definitions or if you want to temporarily exclude certain scenarios from the test execution.

 

To handle expected and unexpected behaviors, you can utilize exceptions within your step definitions.

By throwing specific exceptions, you can handle different scenarios and make assertions about the behavior of your application.

 

Here are some examples and code snippets to illustrate exception handling in Behat:

use Behat\Behat\Context\Context;
use Behat\Behat\Hook\Scope\AfterStepScope;

class SpiceOrderingContext implements Context
{
    /**
     * @Then the spice should be added to the cart
     */
    public function theSpiceShouldBeAddedToTheCart()
    {
        // Code to verify that the spice has been added to the cart

        // If the verification fails, throw an exception
        if (!$spiceAddedToCart) {
            throw new \Exception('The spice was not added to the cart.');
        }
    }

    /**
     * @AfterStep
     */
    public function takeScreenshotOnError(AfterStepScope $scope)
    {
        // Code to take a screenshot when a step fails

        if ($scope->getTestResult()->getResultCode() === \Behat\Testwork\Tester\Result\TestResult::FAILED) {
            // Take a screenshot for further analysis
            // This can help in debugging and identifying the cause of the failure
        }
    }
}

 

In the above example, if the verification of adding the spice to the cart fails, we throw a generic `\Exception` with an error message.

 

This will mark the step as failed and provide information about the failure in the test report.

Additionally, the `AfterStep` hook is used to take a screenshot when a step fails.

 

This can be helpful for further analysis and debugging purposes, as it captures the state of the application at the moment of failure.

By utilizing exceptions, you can handle errors, assertion failures, and unexpected behaviors in your Behat tests.

 

This allows you to make your tests more robust and informative, helping you to identify and fix issues efficiently.

 

Remember to handle exceptions appropriately, provide meaningful error messages, and use helpful hooks or mechanisms for further investigation when necessary.

in the next section of this blog post, I have listed a number of best practices you can use to make your test more useful.

 

Best Practices and Tips

When working with Behat, following best practices can greatly improve the effectiveness and maintainability of your tests.

Here are some recommendations and tips to consider for writing efficient and organized Behat tests:

 

Keep your scenarios focused

Each scenario should test a specific behavior or feature in isolation.

Avoid including multiple functionalities in a single scenario to ensure clarity and ease of maintenance.

 

Scenario: Adding a spice to the cart
    Given I am on the spice catalog page
    When I click on the "Add to Cart" button for a spice
    Then the spice should be added to my cart

 

Use descriptive step definitions

Write clear and concise step definitions that accurately represent the behavior being tested.

This helps in understanding the purpose of each step and makes the tests more readable.

 

/**
 * @Given I am on the spice catalog page
 */
public function iAmOnTheSpiceCatalogPage()
{
    // Code to navigate to the spice catalog page
}

 

Use data tables for multiple inputs

If a step requires multiple inputs or variations, use data tables to provide structured and readable input data.

 

Scenario: Searching for spices
    When I search for the following spices:
        | Spice Name | Quantity |
        | Paprika    | 2        |
        | Cumin      | 1        |
    Then I should see search results for all the spices

 

Organize your context classes

As your test suite grows, organize your context classes into smaller, focused contexts based on functionalities or features.

This helps in maintaining a modular and scalable structure.

 

use Behat\Behat\Context\Context;

class SpiceCatalogContext implements Context
{
    // Step definitions related to spice catalog functionality
}

class CartContext implements Context
{
    // Step definitions related to cart functionality
}

 

Regularly review and refactor your code

Continuously evaluate your tests for readability and maintainability.

 

Refactor your step definitions and scenarios as needed to ensure they remain concise and easy to understand.

By following these best practices, you can create well-structured and maintainable Behat tests for your e-commerce application.

 

Remember to keep your scenarios focused, use descriptive step definitions, utilize data tables for multiple inputs, organize your context classes, and regularly review and refactor your code for improved readability and maintainability.

 

Conclusion

We have explored the basics of implementing BDD using Behat and Gherkin in PHP projects.

We have also seen how Joseph, improved his coding skills and avoided pitfalls by adopting BDD practices.

 

By implementing Behat features and integrating PHP code into tests, you can enhance the quality and reliability of your PHP projects.

Remember the importance of handling exceptions and leveraging them to account for different scenarios in your tests.

 

Stay tuned for future blog posts where we will delve deeper into advanced topics and provide more valuable resources.

Don't forget to subscribe to the newsletter for updates, additional insights, and practical tips to help you excel in web development and software testing.

 

With BDD and Behat, you can transform your development process and build robust and maintainable PHP applications.