Mastering Jest: A Complete Guide to Testing Course Syllabus

Overview: This course provides a comprehensive, project-driven introduction to Jest, the popular JavaScript testing framework. Designed by ex-MAANG engineers, it guides learners from setup to CI/CD integration through interactive lessons, quizzes, and hands-on projects. With approximately 6 hours of content, you'll gain practical experience writing reliable tests for real-world applications—all in a text-based, zero-fluff format optimized for efficient learning.

Module 1: Introduction

Estimated time: 0.25 hours

• What is Jest
• The three primary test types: unit, snapshot, integration
• Exploring the Test with Jest example
• Understanding Jest fundamentals

Module 2: Setting Up Jest

Estimated time: 0.5 hours

• Configuring Jest for JavaScript and TypeScript
• Structuring test files
• Debugging tests
• Installing and configuring Jest in a sample project

Module 3: Jest Matchers

Estimated time: 0.75 hours

• Built-in matchers
• Error handling with Jest
• Using Jest Extended
• Creating custom matchers

Module 4: Writing Unit Tests

Estimated time: 0.75 hours

• Structuring clean unit tests
• Using global helpers
• Best practices for unit testing
• Refactoring legacy functions into unit tests

Module 5: Snapshot Testing

Estimated time: 0.5 hours

• Introduction to snapshots
• Creating and maintaining snapshots
• Common snapshot pitfalls
• Adding snapshot tests for React components or JSON outputs

Module 6: Testing Asynchronous Code

Estimated time: 0.75 hours

• Testing callbacks
• Testing Promises
• Testing async/await patterns
• Writing tests for API-fetch functions

Module 7: Mocking Core Functions & Timers

Estimated time: 1 hour

• Using jest.fn()
• Mocking timers
• Class mocking
• Client/server mocking patterns

Module 8: Mocking External Libraries

Estimated time: 1.25 hours

• Mocking Axios
• Mocking date libraries
• Mocking analytics SDKs
• Mocking charting packages

Module 9: Setup & Teardown

Estimated time: 0.5 hours

• Test isolation principles
• Global setup/teardown
• Per-test hooks
• Implementing beforeAll / afterAll in database tests

Module 10: Test Coverage & CI/CD Pipelines

Estimated time: 0.5 hours

• Generating coverage reports
• Enforcing coverage thresholds
• Integrating with GitHub Actions
• Integrating with CircleCI

Prerequisites

• Familiarity with JavaScript
• Basic understanding of Node.js
• Experience with command line tools

What You'll Be Able to Do After

• Write clean, meaningful unit and integration tests using Jest
• Use Jest matchers and create custom ones for specific data types
• Test asynchronous code with callbacks, Promises, and async/await
• Mock functions, timers, classes, and external libraries effectively
• Integrate Jest into CI/CD pipelines with coverage reporting