Jest.js is a popular JavaScript testing framework developed by Facebook, designed to test web applications and JavaScript code with ease and efficiency. It provides features like zero configuration, built-in test runners, powerful mocking capabilities, and snapshot testing, making it ideal for testing React, Node.js, and other JavaScript-based applications. Learning Jest.js is crucial for aspiring web developers because writing and maintaining reliable tests ensures the stability and quality of applications, a skill highly valued in modern development workflows.
A tutor can accelerate this process by teaching the fundamentals of Jest, guiding learners through creating unit tests, integration tests, and mock functions, and providing practical examples to help them understand how to use Jest in real-world development scenarios effectively.
Chapter 1: Introduction to Jest.js
Lesson 1: What is Jest.js?
Lesson 2: Evolution of Jest: From its inception to modern releases
Lesson 3: Jest vs. Other Testing Frameworks: Comparing Mocha, Jasmine, and others
Lesson 4: Setting Up the Development Environment: Installing Jest with npm/yarn, VS Code setup
Chapter 2: Basic Jest Syntax and Testing Fundamentals
Lesson 1: Understanding Jest Test Structure: Test cases, suites, and assertions
Lesson 2: Writing Your First Jest Test: Basic test case structure
Lesson 3: Matchers in Jest: toBe(), toEqual(), toContain(), and other assertion methods
Lesson 4: Jest CLI Commands: Running tests, watch mode, and debugging
Chapter 3: Testing JavaScript Functions
Lesson 1: Unit Testing with Jest: Understanding pure functions and deterministic tests
Lesson 2: Testing Synchronous Code: Common patterns and best practices
Lesson 3: Testing Asynchronous Code: Promises, async/await, and callbacks
Lesson 4: Mocking Timers and Delays: Using Jest’s timer mocks for setTimeout, setInterval
Chapter 4: Jest Mocking and Spying
Lesson 1: Introduction to Jest Mocks: What, why, and how
Lesson 2: Using jest.fn() and jest.spyOn(): Tracking function calls and return values
Lesson 3: Mocking Modules and Dependencies: Using jest.mock() effectively
Lesson 4: Mocking API Calls: Testing fetch and axios-based calls
Chapter 5: Snapshot Testing
Lesson 1: Introduction to Snapshot Testing: Purpose and use cases
Lesson 2: Creating and Updating Snapshots: Best practices
Lesson 3: Managing Snapshot Changes: When and how to update snapshots
Lesson 4: Using Snapshots with React Components: Testing UI outputs
Chapter 6: Jest and DOM Testing with Testing Library
Lesson 1: Introduction to DOM Testing: Importance and use cases
Lesson 2: Setting Up Jest with Testing Library: Installation and configuration
Lesson 3: Querying the DOM: getByText, getByRole, findBy, and queryBy
Lesson 4: Simulating User Events: Using fireEvent and userEvent
