I'm Samuel Fajreldines

I am a specialist in the entire JavaScript and TypeScript ecosystem (including Node.js, React, Angular and Vue.js)

I am expert in AI and in creating AI integrated solutions

I am expert in DevOps and Serverless Architecture (AWS, Google Cloud and Azure)

I am expert in PHP and its frameworks (such as Codeigniter and Laravel).

Samuel Fajreldines

I am a specialist in the entire JavaScript and TypeScript ecosystem.

I am expert in AI and in creating AI integrated solutions.

I am expert in DevOps and Serverless Architecture

I am expert in PHP and its frameworks.

+55 (51) 99226-5039 samuelfajreldines@gmail.com
Home Page

The Ultimate Guide to Cypress: Introduction, Implementation, and Example Project

Introduction

In the ever-evolving world of web development, testing has become an integral part of the development lifecycle. Ensuring that applications work as intended across different browsers and devices is crucial for delivering a seamless user experience. This is where Cypress comes into play—a powerful end-to-end testing framework that's gaining popularity among developers.

This comprehensive guide will walk you through everything you need to know about Cypress, from understanding what it is and why it's essential, to implementing it in your projects, and finally, creating an example system to demonstrate its capabilities.

What is Cypress?

Cypress is an open-source, next-generation testing tool built for the modern web. Unlike traditional testing frameworks, Cypress is architecturally designed to handle the complexities of modern JavaScript frameworks like React, Angular, and Vue.js. It operates directly in the browser, providing developers with real-time reloading, automatic waiting, and an intuitive API.

Key Features of Cypress

  • Time Travel: Cypress takes snapshots as your tests run. You can hover over commands to see what happened at each step.
  • Debuggability: Cypress provides readable errors and stack traces, making debugging fast and efficient.
  • Automatic Waiting: No need to add waits or sleeps to your tests. Cypress automatically waits for commands and assertions.
  • Real-Time Reloads: Cypress automatically reloads whenever you make changes to your tests.
  • Network Traffic Control: You can stub network traffic as you like, control the response status, delay, and more.

Why Use Cypress?

Cypress addresses many of the pain points developers face when testing modern applications:

  • Easy Setup: No dependencies, extra downloads, or changes to your code. Install Cypress and get started immediately.
  • Fast Execution: Runs in the same run-loop as your application, providing faster test execution.
  • Flake-Free Tests: Eliminates the common issues with flaky tests by providing consistent results.
  • Developer-Friendly: Designed with the developer in mind, offering an interactive GUI and straightforward API.

How to Implement Cypress

Implementing Cypress in your project is straightforward. Let's walk through the steps to get Cypress up and running.

Installation

First, ensure you have Node.js installed, as Cypress is a Node-based application.

Navigate to your project directory and install Cypress using npm:

npm install cypress --save-dev

Alternatively, using yarn:

yarn add cypress --dev

Initial Setup

After installation, open Cypress for the first time to generate the required folders and files:

npx cypress open

This command creates a cypress folder in your project directory with the following structure:

  • fixtures/ - Static data you can use in your tests.
  • integration/ - Your test files (specs) go here.
  • plugins/ - Extend or modify the behavior of Cypress.
  • support/ - Reusable behavior, custom commands, and configurations.

Configuration

You can customize Cypress settings in the cypress.json file. Common configurations include:

{
  "baseUrl": "http://localhost:3000",
  "viewportWidth": 1280,
  "viewportHeight": 720,
  "video": true
}
  • baseUrl: The URL where your app is running.
  • viewportWidth and viewportHeight: The dimensions of the browser viewport.
  • video: Enable or disable video recording of test runs.

Creating an Example System

To demonstrate Cypress in action, we'll set up a simple application and write tests for it.

Setting Up a Sample Application

We'll create a basic Todo application using React (you can choose any framework you're comfortable with).

Step 1: Create a New React App

npx create-react-app cypress-todo-app
cd cypress-todo-app

Step 2: Build the Todo Application

Implement a simple interface where users can add and remove todo items. Ensure your application runs correctly by starting the development server:

npm start

Writing Cypress Tests

With your application running, let's write some tests.

Step 1: Create a New Test File

Inside cypress/integration/, create a file named todo.spec.js.

Step 2: Write Tests

describe('Todo App', () => {
  beforeEach(() => {
    cy.visit('/');
  });

  it('Displays the app title', () => {
    cy.contains('h1', 'Todo App');
  });

  it('Can add a new todo item', () => {
    const newItem = 'Buy milk';
    cy.get('input[name="new-todo"]').type(`${newItem}{enter}`);
    cy.get('.todo-list').should('contain', newItem);
  });

  it('Can remove a todo item', () => {
    const itemToRemove = 'Buy milk';
    cy.get('.todo-list')
      .contains(itemToRemove)
      .parent()
      .find('.delete-button')
      .click();
    cy.get('.todo-list').should('not.contain', itemToRemove);
  });
});

Step 3: Run the Tests

Start Cypress:

npx cypress open

Select the todo.spec.js test file to run the tests interactively.

Running Tests and Analyzing Results

Cypress provides a detailed UI where you can see each test's execution, command by command. You can:

  • View Command Log: See each command executed.
  • Time Travel: Hover over each command to see the state of the application at that moment.
  • Screenshots and Videos: Capture screenshots on test failure and videos of the entire test run.

Advanced Features

To harness the full power of Cypress, consider exploring these advanced features.

Fixtures

Fixtures are used as external pieces of static data that can be used by your tests.

cy.fixture('user.json').then((user) => {
  // Use user data in your tests
});

Custom Commands

Create reusable commands to simplify your tests.

In cypress/support/commands.js:

Cypress.Commands.add('login', (email, password) => {
  cy.visit('/login');
  cy.get('input[name="email"]').type(email);
  cy.get('input[name="password"]').type(password);
  cy.get('form').submit();
});

Use the custom command in your tests:

cy.login('test@example.com', 'password123');

Continuous Integration with Cypress

Cypress can be integrated into your CI/CD pipeline to run tests automatically.

Example with GitHub Actions

Create a .github/workflows/cypress.yml file:

name: Cypress Tests

on: [push]

jobs:
  cypress-run:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Install Dependencies
        run: npm install
      - name: Run Cypress Tests
        run: npx cypress run

This workflow will run your Cypress tests on every push to the repository.

Conclusion

Cypress is a robust and developer-friendly testing tool that simplifies end-to-end testing for modern web applications. Its easy setup, powerful features, and excellent documentation make it an essential tool for developers looking to enhance their testing strategy.

By implementing Cypress in your projects, you can ensure higher code quality, reduce bugs, and deliver a better user experience. Whether you're a seasoned developer or new to testing, Cypress offers the tools you need to write effective and efficient tests.

Additional Resources

Resume

Experience

  • SecurityScoreCard

    Nov. 2023 - Present

    New York, United States

    Senior Software Engineer

    I joined SecurityScorecard, a leading organization with over 400 employees, as a Senior Full Stack Software Engineer. My role spans across developing new systems, maintaining and refactoring legacy solutions, and ensuring they meet the company's high standards of performance, scalability, and reliability.

    I work across the entire stack, contributing to both frontend and backend development while also collaborating directly on infrastructure-related tasks, leveraging cloud computing technologies to optimize and scale our systems. This broad scope of responsibilities allows me to ensure seamless integration between user-facing applications and underlying systems architecture.

    Additionally, I collaborate closely with diverse teams across the organization, aligning technical implementation with strategic business objectives. Through my work, I aim to deliver innovative and robust solutions that enhance SecurityScorecard's offerings and support its mission to provide world-class cybersecurity insights.

    Technologies Used:

    Node.js Terraform React Typescript AWS Playwright and Cypress