Capybara has become an essential tool for Ruby developers. As a developer, having a strong grasp of Capybara can help you land your next job. That’s why I’ve put together the top 25 Capybara interview questions that you’re likely to encounter during a job interview
Whether you’re a Capybara expert looking to brush up or just starting with Capybara, this guide will help prepare you to ace those tough technical interviews and land the job Let’s dive in!
Capybara is an open-source web application testing framework used for automation testing in Ruby It simulates how a real user would interact with your app by mimicking actions like clicking links, filling out forms, and more
Here are some of Capybara’s key features:
- Domain Specific Language (DSL) that reads like English for writing tests
- Supports testing web apps built with frameworks like Rails and Sinatra
- Works with JavaScript-heavy sites and SPAs
- Integrates with frameworks like RSpec, Cucumber, and Minitest
- Supports multiple drivers like Selenium, RackTest, and Webkit
Now let’s look at some common Capybara interview questions.
Top Capybara Interview Questions and Answers
Q1. What is Capybara used for?
Capybara is a framework for testing web apps by automating and simulating how users interact with them. You can write acceptance and feature tests from the point of view of an end user to make sure your app works the way it should.
Some examples of using Capybara include:
- Testing form submissions and validations
- Clicking buttons, links, and interacting with other elements on a page
- Filling out and submitting web forms
- Verifying content on pages and if elements are visible
- Testing JavaScript-heavy sites and SPAs
Q2. What are some key features of Capybara?
Some key features of Capybara include:
- Domain Specific Language (DSL) that is easy to read and understand
- Supports testing web apps built with Rack, Rails, Sinatra etc.
- Integrates seamlessly with testing frameworks like RSpec, Cucumber, Minitest
- Asynchronous JavaScript support through waiting and automatic retry
- Supports multiple drivers like Selenium, RackTest, Webkit
- Database transaction rollback after each test for clean state
- Built-in query methods like text searching, CSS selectors, XPath
Q3. How does Capybara interact with web pages?
Capybara interacts with web pages similarly to how an actual user would. It allows you to simulate user actions such as:
- Visiting pages using
visitmethod - Clicking on links, buttons using
click_link,click_button - Filling out forms using
fill_in - Selecting radio buttons and checkboxes
- Interacting with drop downs
- Triggering JavaScript events
- Executing JavaScript directly using
execute_script
This provides a realistic way to automate and test web pages through a user perspective.
Q4. What is the difference between Capybara and Selenium?
The main differences between Capybara and Selenium are:
- Capybara is built specifically for Ruby testing, while Selenium is language-agnostic.
- Capybara provides a domain specific language and high-level API, Selenium uses JavaScript for browser automation.
- Capybara depends on drivers like Selenium to interact with browsers. It is a testing framework.
- Selenium is a browser automation library that Capybara integrates with using the Selenium driver.
- Capybara tests can simulate user behavior, Selenium focuses on lower-level browser interactions.
In essence, Capybara is a testing DSL that utilizes Selenium under the hood as one of its drivers.
Q5. What drivers does Capybara support?
Capybara supports the following drivers:
- RackTest: Fast headless driver for non-JavaScript testing
- Selenium: For JavaScript testing through an actual browser
- Webkit: Headless browser driver based on QtWebkit
- Capybara-webkit: Similar to Webkit but uses more lightweight browser
- Poltergeist: Built on top of PhantomJS headless browser with jQuery support
By default, Capybara uses the RackTest driver for fast and simple testing. For testing JavaScript, Selenium and Webkit are commonly used.
Q6. How can you switch between different drivers in Capybara?
You can switch between different Capybara drivers by setting Capybara.current_driver to the driver you want to use. For example:
Capybara.current_driver = :selenium # switches to selenium This will switch to using the Selenium driver. Once done with the tests where Selenium is required, you should reset back to the default driver:
Capybara.use_default_driver # resets to default driverYou can also set the default driver globally in your config or spec helper file.
Q7. What methods does Capybara provide for interacting with elements on a page?
Some common Capybara methods for interacting with elements are:
fill_in– Finds a field on the page and fills it in with provided valuechoose– Finds a radio button and marks it as checkedcheck– Finds a checkbox and checks itclick_link_or_button– Clicks on a link or button elementattach_file– Finds a file input and attaches a file to itselect– Finds a select box and selects an option from it
Additionally, you can use find or all to locate elements and then perform actions like click on them. There are also assertion methods like has_text?, has_content? etc.
Q8. How would you fill out a form using Capybara?
Here is how to fill out a form using Capybara:
visit '/form' fill_in 'First Name', with: 'John'fill_in 'Last Name', with: 'Doe'fill_in 'Email', with: '[email protected]'choose 'Male'check 'Sign up for newsletter'select 'Ruby', from: 'Languages' attach_file 'Resume', '/path/to/resume.pdf'click_button 'Submit'We first visit the page. Then use fill_in to fill text fields, choose for radio buttons, check for checkboxes. We also use select for dropdowns and attach_file for file uploads. Finally, we submit the form by clicking the submit button.
Q9. How would you click on a link using Capybara?
There are two ways to click on a link using Capybara:
1. Using CSS selector:
click_link('Home') # clicks link with text 'Home'click_link('#home-link') # clicks link with id 'home-link' 2. Finding link and clicking:
link = find(:link, 'Home') link.clickThe first approach uses the built-in click_link method to find and click the link directly. The second approach uses find to locate the link, save it in a variable, and then performs click on it.
Q10. How can you access an element within a specific section in Capybara?
You can use the within method in Capybara to access elements within a specific section:
within('#navigation') do click_link 'Home' click_link 'About' endHere we perform actions only on links within the section having id #navigation. Anything outside that section will be ignored. This helps scope actions when there are similar elements on different parts of the page.
Q11. What methods does Capybara provide for asserting page contents?
Some useful Capybara methods for asserting page contents are:
has_text?– Checks if text is present on the pagehas_content?– Checks if content exists on the pagehas_css?– Checks for presence of CSS selectorhas_button?– Checks if button exists on the pagehas_checked_field?– Checks if a checkbox/radio is checkedhas_select?– Checks if select box exists on the pagehas_table?– Checks if table selector exists on the page
These assertions verify the state of different elements and contents on the page. They are commonly combined with expect to write expectations.
Q12. How would you check if an image is displayed on the page?
We can check if an image is displayed using:
expect(page).to
What we’re going to do
One of the biggest challenges in getting started with testing is just that—the simple act of getting started. What I want is for you, my dear reader, to get a small but important “win” as soon as possible. You will have written your first test for a Rails app by the end of this chapter, even if you have never done it before.
Here’s what we’re going to do:
- Start up a Rails app that is as simple as possible. Make one static page that just says “Hello, world!” Write one test (using RSpec and Capybara) that makes sure our static page really does say “Hello, world!”
The goal here is just to walk through the motions of writing a test. The test itself is rather pointless. It’s not likely that I’d ever write a test that only checks the content of a static page. But the point isn’t to make a real test; it’s to give you a mental “Lego brick” that you can later put together with other mental Lego bricks. Writing tests get really hard very quickly, so I think it’s helpful to start with something that’s almost too easy to be true.
The tools we’ll be using
We’ll be using RSpec (rumored to be the most popular Rails testing framework) and Capybara (a library that lets browsers do things like click buttons, fill out forms, etc.) for this exercise. ) using Ruby. You may find some of the RSpec or Capybara syntax confusing or indecipherable. You also may well not understand where the RSpec stops and the Capybara starts. For the purposes of this “hello world” exercise, that’s okay. Right now, we don’t want to fully understand things. Instead, we want to start moving forward.
I interviewed animals with a tiny mic again
FAQ
What is Capybara framework?
What is the wait method in capybara?
Why use capybara?
How does capybara work?
Capybara can talk with many different drivers who execute your tests through the same clean and simple interface. You can seamlessly choose between Selenium, Webkit, or pure Ruby drivers. Capybara automatically waits for your content to appear on the page, you never have to issue any manual periods of sleep.” fill_in ‘username’, :with =>; user
How do capybaras communicate?
Communication among capybaras is rich and includes a variety of vocalizations like purrs, whistles, barks, and squeals. They also communicate through body postures and, to a lesser extent, scent markings. An interesting aspect of their behavior is their symbiotic relationship with various bird species.
What is capybara in Ruby?
First, let’s start with definitions. What is Capybara? On Capybara’s official page it is described as follows: “ Capybara is a library written in the Ruby programming language which makes it easy to simulate how a user interacts with your application.
Can a capybara swim?
Its legs are relatively short, but it moves both on land and in water with surprising agility. A noticeable feature of the capybara’s anatomy is its webbed feet, which makes it an excellent swimmer. These animals are adept at staying submerged, able to remain underwater for up to five minutes.
