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Hey there! Learning something new can feel intimidating. Cucumber, a popular testing framework, certainly falls in that category with its unique syntax.
But I‘m here to show you that Cucumber is approachable for beginners. With hands-on experience, you‘ll gain confidence and pick up skills that will serve you for years to come.
In this comprehensive guide, I‘ll walk you step-by-step through:
- Why teams use Cucumber
- Writing your first test scenario
- Connecting scenario steps to Ruby code
- Running your test for the first time
- Best practices for next steps
I‘ll share plenty of examples, data, and visuals along the way. By the end, you‘ll see how Cucumber can transform testing on your projects!
Why Leading Teams Use Cucumber
Before we dig in, it‘s important to level-set on why Cucumber has become so popular.
Cucumber enables collaboration across teams with simple text-based descriptions of system behavior. Here is an example:
Feature: User login
Scenario: Valid user login
Given the user visits the login page
When they submit valid credentials
Then they should be logged in successfullyThis reads clearly even to non-technical folks. The Given-When-Then structure tells a discrete story of what should happen.
These scenarios act as living documentation that is verified automatically with each test run. They describe how the system should work in plain language that even product managers and UX researchers can understand.
By collaborating on scenarios, the entire team builds shared understanding of the application‘s expected behavior. This acts as a single source of truth across departments.
Scenarios are then tied directly to automated browser tests through Ruby step definitions behind the scenes. This gives you regression testing that updates alongside the documentation:
Given("the user visits the login page") do
visit("/login")
end
When("they submit valid credentials") do
fill_in("Email", with: "[email protected]")
fill_in("Password", with: "password")
click_button("Login")
end So Cucumber combines collaboration through well-written documentation with automated testing velocity.
Adoption By Leading Organizations
Given these strengths, it‘s no wonder that Cucumber has seen massive enterprise adoption since its launch in 2008:
- 62% of teams using BDD rely on Cucumber as their primary framework. [State of Testing Report 2019]
- Cucumber has over 21,000 starred GitHub projects with hundreds of contributors. [GitHub]
- Brands like JP Morgan, BBC, Adobe, and Samsung use Cucumber for test automation. [Cucumber Case Studies]
Additionally, Cucumber skills are highly sought after by employers:
- Listings requesting "Cucumber" have grown roughly 20% yearly over the past 5 years. [Indeed.com]
- In some cities like London, over 1,500 open job listings actively recruit Cucumber experience. [CWJobs.co.uk]
As you can see, Cucumber is relied upon by industry leaders and provides valuable skills. Now let‘s get those skills ourselves!
Writing Your First Scenario
We‘ll stick to basics in this guide. To follow the examples, you‘ll need:
- Ruby. The examples use Ruby but Cucumber works with Java and other languages too.
- A text editor like VS Code.
- The Cucumber Ruby gem. Install this by running
gem install cucumberin your terminal.
The first step is to create a place to store your test files. Make a new project folder like first-cucumber-project and open it in your editor.
Inside this project, Cucumber expects to find .feature files for each test scenario in a features folder. So create these using your terminal or editor:
mkdir features
touch features/login.featureOpen up login.feature and add this:
Feature: User login
Scenario: Valid user can log in
Given the user is on the login page
When they submit a valid username and password
Then they should be logged in successfullyCongratulations, you just wrote your first test in Cucumber! 🎉
Some key points:
FeatureandScenarioact as descriptors for each test.- Steps start with
Given/When/Thenand read sequentially like instructions. - The language is plain and conversational using terms the whole team knows.
Together they describe the expected behavior – users with valid credentials should be able to log in.
Pretty straightforward, while covering exactly what we want to test.
Linking Scenario Steps to Code
On their own, scenarios act as living documentation that describe system behavior. The true power comes from linking steps to automated checks.
When a step matches Cucumber code written in Ruby, that code is executed to validate the step. We call these matched blocks step definitions.
Let‘s try this out. Create a step_definitions folder with a file called login_steps.rb:
mkdir step_definitions
touch step_definitions/login_steps.rbIn this file we‘ll start matching code to the "Given" step:
Given("the user is on the login page") do
visit("/login")
endThe match syntax is "Step text from the scenario". This step definition navigates to the /login page.
Follow the same pattern for the other steps:
When("they submit a valid username and password") do
fill_in("Email", with: "[email protected]")
fill_in("Password", with: "password")
click_button("Login")
end
Then("they should be logged in successfully") do
expect(page).to have_content("Welcome Back!")
endClicking elements and asserting page contents automates the login process.
With the plain text scenario and its linked Ruby step code, you now have a complete automated test!
The collaboration benefits come from sharing expected behavior through the scenario. Automation velocity comes from directly tying those scenarios to code.
This living documentation powered by tests is at the heart of Cucumber‘s value.
Executing Your First Automated Test
It‘s time to see a live run of your test! In your terminal, run:
cucumber Cucumber will search features and step definitions, triggering each step‘s matching code.
In the terminal Cucumber shows the test progress, logging each step as they pass:
And congratulations – you just executed your first automated browser test with Cucumber! 🥳
Now that you‘ve seen Cucumber test runs in action, let‘s solidify what you‘ve learned with some best practices.
Next Steps and Best Practices
Here are key ideas to help you start testing effectively with Cucumber:
1. Focus scenarios on behavior, not individual features – Concentrate on the what not how. Higher-level outcomes make better guides.
2. Keep scenarios small and tests atomic – Broken down stories with tight focuses aid understanding and modularity.
3. Utilize "Roles" placeholders – Write steps with user roles like "the admin" rather than specifics like "Bob".
4. Reuse step definitions between scenarios – Common steps like login can be defined once.
Putting these ideas into practice takes some experience. As you write more test scenarios, consider:
- What customer problems am I solving? How does this behavior add value?
- Can I break this down into smaller, more atomic interactions?
- Are my scenarios focused on the value, not technical details?
- Can these steps be reused across features?
Stepping back and asking questions keeps your Cucumber foundation solid as you scale up test coverage.
Where To Go From Here
Congratulations, you wrote and ran your first automated test script with Cucumber! 🎊
You‘ve only scratched the surface of possibilities though. Some ideas for leveling up:
- Add more scenarios covering different user login paths.
- Look into Cucumber hooks to execute setup code.
- Check reports after runs to visualize results.
- Build helper methods that can be shared between step definitions.
- Set up a test runner like RSpec to manage test execution.
There is always more to learn with test automation. But now you‘ve got a first script under your belt and know the Cucumber basics.
The collaborative nature of Cucumber tests can transform how teams view the test mission. Product, UX, QA, and devs can build shared wisdom. This pays dividends across the organization.
I hope you‘ve found this guide helpful for getting started. Automated testing requires dedication, but brings many rewards. Spending time up front defining system behavior avoids major quality issues down the road.
If anything was confusing, don‘t hesitate to reach out! Happy to help new Cucumber users any way I can.
Now…go unleash behavior-driven testing superpowers on the world! 😉