Introduction to Cypress with Cucumber for End-to-End Testing

End-to-end (E2E) testing is an integral part of modern software development. It ensures that applications function as intended from the user’s perspective, covering critical workflows and integrations. Combining Cypress, a popular E2E testing framework, with Cucumber, a behavior-driven development (BDD) tool, offers a powerful way to write and execute tests that are both robust and easy to understand.

This article explores how Cypress and Cucumber can work together to streamline E2E testing and highlights the benefits of this approach.

What is Cypress?

Cypress is a JavaScript-based E2E testing framework designed for modern web applications. It provides:

Fast and reliable tests: Running directly in the browser ensures quick feedback.
Automatic waiting: Cypress automatically waits for elements to appear or requests to complete.
Powerful debugging: With time travel and detailed logs, debugging test failures becomes easier.

Cypress is developer-friendly, offering a seamless setup process and an intuitive API that reduces the barrier to entry for testing.

What is Cucumber?

Cucumber facilitates behavior-driven development (BDD) by allowing developers and stakeholders to write test cases in plain English. These test cases, called features, use the Gherkin syntax, which makes them accessible to both technical and non-technical team members.

A Gherkin feature file looks like this:

Feature: Login functionality

  Scenario: Successful login
    Given the user is on the login page
    When they enter valid credentials
    Then they should see the dashboard

Each line corresponds to a step that maps to a function in the test implementation.

Why Combine Cypress and Cucumber?

While Cypress excels at writing and executing tests, its syntax and output are primarily developer-centric. By integrating Cucumber, teams can:

Improve Collaboration: Non-developers, such as QA engineers and product managers, can contribute to test creation.
Enhance Readability: Gherkin syntax bridges the gap between technical and non-technical stakeholders.
Maintain Better Test Documentation: Feature files serve as living documentation for the application’s behavior.

Setting Up Cypress with Cucumber

Here’s how to integrate Cypress and Cucumber in a project:

Step 1: Install Required Dependencies

To get started, install the necessary packages:

npm install cypress @badeball/cypress-cucumber-preprocessor cucumber

The @badeball/cypress-cucumber-preprocessor package serves as the bridge between Cypress and Cucumber, enabling feature file execution.

Step 2: Configure Cypress

Modify your cypress.config.js file to enable the Cucumber preprocessor:

const { defineConfig } = require('cypress');
const createBundler = require('@bahmutov/cypress-esbuild-preprocessor');
const addCucumberPreprocessorPlugin = require('@badeball/cypress-cucumber-preprocessor').addCucumberPreprocessorPlugin;

module.exports = defineConfig({
  e2e: {
    async setupNodeEvents(on, config) {
      await addCucumberPreprocessorPlugin(on, config);
      on('file:preprocessor', createBundler());
      return config;
    },
    specPattern: 'cypress/e2e/**/*.feature',
  },
});

This configuration sets up the Cucumber preprocessor and ensures Cypress recognizes .feature files.

Step 3: Write a Feature File

Create a new .feature file under cypress/e2e. For example:

Feature: Search functionality

  Scenario: Search for a product
    Given the user is on the homepage
    When they search for "laptop"
    Then they should see results for "laptop"

Step 4: Implement Step Definitions

Create a JavaScript file in the same directory to define the steps:

import { Given, When, Then } from '@badeball/cypress-cucumber-preprocessor';

Given('the user is on the homepage', () => {
  cy.visit('/');
});

When('they search for {string}', (searchTerm) => {
  cy.get('[data-cy=search-input]').type(searchTerm);
  cy.get('[data-cy=search-button]').click();
});

Then('they should see results for {string}', (searchTerm) => {
  cy.contains(searchTerm).should('be.visible');
});

Each step in the feature file maps to a corresponding Cypress command in the implementation.

Step 5: Run the Tests

Execute the tests using the Cypress Test Runner:

npx cypress open

Select your feature file to run and observe the results.

Best Practices for Cypress with Cucumber

Organize Your Tests: Store feature files and step definitions in a structured folder hierarchy for better maintainability.
Re-use Steps: Share step definitions across scenarios to reduce duplication.
Focus on Readability: Write concise and meaningful steps in feature files to ensure clarity for all stakeholders.
Use Data Attributes: Use unique data-cy attributes for element selectors to make tests resilient to UI changes.
Leverage Parallel Testing: Run tests in parallel to speed up execution, especially for large test suites.

Benefits of Cypress with Cucumber

Enhanced Collaboration: Feature files create a shared understanding between developers, testers, and business stakeholders.
Increased Test Coverage: Gherkin encourages thinking about user behavior, leading to comprehensive test cases.
Fast Feedback Loops: Cypress’s real-time feedback, combined with human-readable scenarios, speeds up the debugging process.

Conclusion

Cypress and Cucumber form a powerful combination for end-to-end testing in modern web applications. By leveraging Cypress’s robust testing capabilities with Cucumber’s readable syntax, teams can build reliable tests that are both easy to write and understand. This approach fosters collaboration and ensures high-quality user experiences.

As web applications grow in complexity, adopting tools like Cypress with Cucumber enables teams to keep pace with development demands while maintaining software quality.

Categories:End-to-End TestingTesting