Javascript

Learn the basics of end-to-end testing in a real browser, and how to install Playwright, write tests, and run them with UI mode and Codegen.

Review Parts 1–14, see how TDD changed the code, and explore where to go next with end-to-end and visual regression testing.

Explore the costs and benefits of introducing TDD to a production project, strategies for adopting it as a team, and how CI/CD makes testing sustainable.

Compare unit, integration, and end-to-end tests, and learn how the Testing Trophy guides an effective React testing strategy.

Learn to write robust tests that survive internal changes by avoiding implementation details and focusing on user behavior.

Recognize hard-to-test components and improve testability through UI/logic separation and provider-aware test setup.

Use userEvent.type to simulate text input and verify validation messages when required fields are missing.

Introduce Mock Service Worker to intercept network requests, manage mock responses, and test success and server-error cases without a real server.

Learn to test asynchronous operations such as API calls, and verify Loading, Success, and Error states with findBy queries.

Extract business logic into a custom hook and test it independently with renderHook and act.

Test conditional rendering as React state changes, and learn when to use getBy and queryBy.

Refactor a React component by extracting a reusable child component, and use existing tests to confirm the behavior remains reliable.

Implement the minimum component code to turn failing tests green, then use useState to complete its interactive behavior.

Learn to test React from the user’s perspective, use accessibility queries, and write a failing test as the first TDD step.

Create a React project with Vite, then configure Vitest and React Testing Library for test-driven development.

Learn why frontend testing matters, what TDD offers React projects, and which behaviors to cover with tests.

Compare local storage and session storage by persistence and scope, see how they differ from cookies, and review common interview questions.

Explore how JavaScript determines the value of its most confusing concept, this. Learn the four binding rules based on how a function is called, the special behavior of arrow functions, and key interview questions.

Understand JavaScript closures, hoisting, and event bubbling, including scope chains, the TDZ, event propagation, delegation, and common interview questions.

Learn essential JavaScript array methods, object operations, and the Set and Map data structures for coding challenges.

Part 1 of a JavaScript fundamentals series for coding tests. Learn variables, basic operators, essential string operations such as slicing, concatenation, searching, and replacement, plus basic number and array manipulation through clear examples.