#jest Development Tutorials & Tips | Roast Dev

Jest - Solution for "Jest encountered an unexpected toke"

Pre-study Compiling Vs. TranspilingJest Code TransformationJest docs – transformIgnorePatterns Background When running unit tests using Jest, get the error as below ⛶Jest encounte...

05.05.2025 0 Read More

Jest - Mocking Next.js Image to handle dynamic properties in tests

Pre-study Next.js - Image ComponentImporting images used the 'import' keyword for the image 'src' breaks jest test #26749Jest - Manual MocksReact Testing LibraryMDN JavaScript - Rest paramete...

05.05.2025 0 Read More

🧪 React Testing: Tips That Actually Work

1. Test What Users See, Not What Developers Write ⛶// 👎 Don't do this test('component sets loading state', () => { const wrapper = shallow(<UserProfile />); expect(wrapper.s...

19.03.2025 0 Read More

How To Fix the import.meta.env Error in a Vite + Jest Setup

If you’ve worked with Vite for building a React (or other) application and used Jest for testing, you might have encountered an error like: ⛶The 'import.meta' meta-property is only allowed when th...

19.03.2025 0 Read More

Mastering Jest: A Beginner's Guide to JavaScript+NodeJs Testing with Fun Examples -1

Writing code is fun, but debugging is painful! Jest helps us catch bugs early and ensures our JavaScript code works correctly.In this post, I am going to explain how i understood Jest in a most easies...

20.03.2025 0 Read More

Biblioteca de componentes React e typescript, parte 3: testes unitários com Jest e testing library

Introdução English version: React and typescript components lib, part 3: unit tests with Jest and testing libraryNa parte três da série, será incrementada a lib com a definição de test...

24.03.2025 0 Read More

React and typescript components lib, part 3: unit tests with Jest and testing library

Introduction Portuguese version: Biblioteca de componentes React e typescript, parte 3: testes unitários com Jest e testing libraryIn part three of the series, the library will be enhanced w...

24.03.2025 0 Read More

AI as a Coding Tool: A Mixed Experience

Even though AI has been a hot topic in recent times, I had been reluctant to use it in my work as I have always trusted my own research instead of getting an answer directly from someone or something....

30.03.2025 0 Read More

How to Detect Low Test Coverage Files in Jest

How to Detect Low Test Coverage Files in Jest (JavaScript/TypeScript) Through observing our customers' behavior, we've noticed a common challenge when teams want to improve their test coverag...

30.03.2025 0 Read More

Unit Testing React Components with Jest and React Testing Library

Introduction Let's face it—testing isn't always the most exciting part of building React apps. But trust me, your future self will thank you for taking the time to write good tests. I've be...

31.03.2025 0 Read More