Challenges
- Pick a challenge by category, language, or difficulty (kyu).
- Write your solution in the code editor.
- Submit to check if your code passes the test suite.
- Rank up from 8 kyu (beginner) toward 1 dan (master).
Sharpen your skills. Rank up from 8 kyu to 1 dan.
Build a Test Report Parser
Parse JUnit XML test results and return structured data: total tests, passed, failed, skipped, and failure details.
Race Condition Detective
This banking transfer function has a race condition. Identify it, explain why it's dangerous, and write a test that c...
API Response Validator
Build a function that validates an API response against a schema. Check types, required fields, and nested objects.
Build a Test Data Generator
Create a function that generates random test data for a user registration form: name, email, password, age. Each call...
Page Object Pattern
Refactor this messy Selenium test into a clean Page Object. Separate locators from test logic.
Parse a Test Result
Given a string of test results like 'PPFPFP' (P=pass, F=fail), return a dict with counts of passes and failures.
Validate Email Format
Write a function that validates if a string is a properly formatted email address. Think about what a tester would ch...
Spot the Boundary Bug
This function calculates shipping cost based on weight. It has 3 boundary value bugs. Find them by writing failing te...
Equivalence Partitioning Exercise
An age field accepts values 0-120. Identify the equivalence classes and write one test per class.
Write Your First Assertion
Write a function that takes two values and returns true if they're equal, false otherwise. Then write an assertion to...
FizzBuzz for Testers
Classic FizzBuzz but with a testing twist: write the function AND list 5 edge cases you'd test.
Write 3 Test Cases
Given this login requirement: 'Users must enter a valid email and password (min 8 chars) to log in.' Write 3 test cas...
First Assertion (Ruby)
Write your first assertion in Ruby. Compare two values and verify they're equal.
First Assertion (Javascript)
Write your first assertion in Javascript. Compare two values and verify they're equal.
First Assertion (Java)
Write your first assertion in Java. Compare two values and verify they're equal.
First Assertion (Csharp)
Write your first assertion in Csharp. Compare two values and verify they're equal.