# Capybara — Acceptance Testing Framework for Ruby Web Apps

> A Ruby library that simulates real user interaction with web applications, providing a unified API for browser-based integration and acceptance testing.

## Install

Save as a script file and run:

# Capybara — Acceptance Testing Framework for Ruby Web Apps

## Quick Use
```ruby
# Gemfile
gem 'capybara'
gem 'selenium-webdriver'
```
```ruby
require 'capybara/rspec'
describe 'Sign in', type: :feature do
  it 'lets a user log in' do
    visit '/login'
    fill_in 'Email', with: 'user@example.com'
    click_button 'Sign in'
    expect(page).to have_content 'Welcome'
  end
end
```

## Introduction
Capybara is a Ruby acceptance testing library that simulates how a real user interacts with a web application. It provides a clean DSL for visiting pages, filling in forms, clicking buttons, and asserting on page content, making end-to-end tests readable and maintainable.

## What Capybara Does
- Simulates user actions like clicking, typing, and navigating in tests
- Provides a driver-agnostic API that works with Rack, Selenium, and headless browsers
- Automatically waits for asynchronous content to appear before assertions
- Scopes interactions to specific page sections with within blocks
- Integrates directly with RSpec, Minitest, and Cucumber

## Architecture Overview
Capybara defines an abstract session interface and delegates actual browser interaction to pluggable drivers. The default Rack driver runs against your app in-process without a real browser. For JavaScript-heavy apps, the Selenium driver controls Chrome or Firefox. Each driver translates the Capybara DSL into the appropriate browser commands while the framework handles waiting, scoping, and synchronization.

## Self-Hosting & Configuration
- Add capybara to your Gemfile and bundle install
- Set the default driver in your test helper (rack_test, selenium, or cuprite)
- Configure the app host and server port for remote testing
- Set default_max_wait_time to control how long Capybara waits for elements
- Register custom drivers for headless Chrome or specific browser profiles

## Key Features
- Intuitive DSL that reads like plain English test steps
- Smart automatic waiting that eliminates manual sleep calls
- Multiple driver support from fast in-process to full browser testing
- Built-in matchers like have_content, have_selector, and have_field
- Session snapshots with save_and_open_page for debugging failures

## Comparison with Similar Tools
- **Selenium WebDriver (raw)** — lower-level API without built-in waiting or DSL
- **Playwright for Ruby** — newer, supports more browsers but smaller Ruby ecosystem
- **Cypress** — JavaScript-only, different language ecosystem
- **Watir** — Ruby browser automation with a different API style
- **SitePrism** — page object layer that builds on top of Capybara

## FAQ
**Q: Does Capybara support JavaScript-rendered pages?**
A: Yes, when using the Selenium or Cuprite driver. The default Rack driver does not execute JavaScript.

**Q: How does it handle AJAX waits?**
A: Capybara automatically retries assertions for up to default_max_wait_time seconds, so AJAX updates are handled without explicit sleeps.

**Q: Can I run tests in headless mode?**
A: Yes. Register a headless Chrome or Firefox driver, or use the Cuprite driver which runs headless by default.

**Q: Is it only for Rails?**
A: No. Capybara works with any Rack-compatible application, including Sinatra and Hanami. Remote apps can also be tested via a URL.

## Sources
- https://github.com/teamcapybara/capybara
- https://rubydoc.info/github/teamcapybara/capybara

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Author: Script Depot