Meticulous AI Blog
Read various posts about JavaScript, testing, and frontend development.

How to Speed Up Your Frontend Monorepo Build
An overview of how to speed up your frontend monorepo build


How to Test a TypeScript App with Jest | A Step-by-Step Tutorial


Visual Regression Testing | 6 Tools to Use
A guide on choosing the right visual regression testing tool.


Visual Regression Testing | The Beginner Guide in 2023
A guide covering the benefits of visual regression testing, automated vs. manual testing, as well as a description of Meticulous, a tool for visual regression testing without a maintenance burden.


Meticulous Announces $4 million Seed Round to Help Developers Make the World's Code Safe, Performant and Reliable
Meticulous, a Y Combinator startup, has closed a $4 million Seed Round to build the first automated front-end testing software for developers.


Safer Exhaustive Switch Statements in TypeScript
A guide on various methods and techniques for implementing safer switch and if/else statements, including use of the never type and eslint rules.


Debugging React Testing Library Tests | A Beginner’s Guide in 2023
A beginner’s guide to debugging React testing library tests, with a code walkthrough of how to use react-testing-library to debug tests.


How to Prevent "Cannot Read Property Split of Undefined"
An article about the error 'cannot read property split of undefined' and various techniques to prevent it.


Axios vs Fetch | Which is Best for Beginners?
A breakdown of the trade-offs and differences between these two different methods of making network requests in JavaScript.


Frontend Unit Testing | Best Practices & Tutorial
A guide on some of the best practices for frontend unit testing, including covering libraries like Jest with various code examples.


IndexedDB | Guide to Getting Started, Tutorial, & Best Practices
A tutorial on how to get started with IndexedDB and whether you should use it, with an example code walkthrough.


Logging in React | In-Depth Guide & Tutorial
How to effectively log info and error messages within a React application, and the best practices for doing this.


Visual Regression Testing in a React App | Step-by-Step Tutorial
A guide on how to do visual regression testing in a React app - a step-by-step tutorial. This includes an introduction to visual regression testing, spinning up an example app and a step-by-step guide on creating some visual regression tests.


JavaScript Syntax Errors | How to Prevent Them, Tutorial
The complete guide on JavaScript Syntax Errors, how they occur, and techniques and tools available to prevent them.


How to Prevent the Error: Cannot Read Property '0' of Undefined
A guide on how to prevent the error "cannot read property '0' of undefined", covering techniques such as try, catch, using const over let, amongst many other techniques to prevent this error.


How to Prevent the TypeError: Cannot Read Property Map of Undefined
A guide on the root cause of 'cannot read map of undefined' as well as techniques and tools to prevent this error.


How to Set up Visual Regression Tests
A how-to guide on how to set up visual regression testing in a web application using Jest and Cypress.


How to use Jest spyOn with React.js and Fetch
Follow this step-by-step guide on Jest's SpyOn method, with a practical example using React and Fetch. This post also includes a comparison to mocks.


How to Use React Testing Library to Wait for Async Elements | Step-by-Step Guide
A guide on how to use React Testing Library's to wait for and test asynchronously loaded elements. Contains code examples and a step-by-step walkthrough.


Is Selenium Worth it in 2023? | In-Depth Analysis
An overview of Selenium and a discussion on whether it's worth it relative to the other tools available


JavaScript Reference Errors | How to Prevent Them, Tutorial
The complete guide on JavaScript ReferenceErrors, how they can occur, and techniques and tools available to prevent them.


JavaScript Regressions and How to Prevent Them
An exploration of why JavaScript regressions are important and an overview of automated testing techniques to prevent their occurrence.


JavaScript Try Catch | Complete Guide & Tutorial
A guide on the try-catch functionality available in JavaScript, it's quirks and tips on using this most effectively.


JavaScript TypeErrors and Techniques to Prevent Them
A short guide on best practices, techniques and existing tooling available to prevent TypeErrors in JavaScript or TypeScript.


JavaScript UI Testing | Best Practices, Tutorial
A guide on the best practices in JavaScript UI testing, from behavior driven development, to naming conventions, to what browsers to execute tests within.


JavaScript Unshift | In-Depth Guide & Tutorial
An in-depth guide on the API, quirks and performance of JavaScript's unshift method, as well as best practices when using it.


Let Your Users Write Your Tests for You | Part I
An explanation of what replay testing is, how to leverage user session data to create automated tests, and an overview of existing companies using replay testing.


JavaScript LocalStorage | In-Depth Guide & Tutorial
The complete guide on LocalStorage, it's API, a code walkthrough, and various trade-offs and limitations compared to other storage options.


Mocking a JavaScript Class with Jest, Two Ways to Make it Easier
A guide on how to mock a JavaScript class using Jest, comparing dependency injection and mocking, along with guides on how to implement both.


JavaScript RangeErrors | How to Prevent Them, Tutorial
The complete guide on JavaScript RangeErrors, how they can occur, and techniques and tools available to prevent them.


React Error Boundaries | Complete Guide
A complete guide to implementing React Error Boundaries, and how to use a third-party tool for handling more sophisticated scenarios.


Testing Pyramid for Frontend | In-Depth Tutorial
An overview and discussion of the testing pyramid, the balance between unit tests, integration tests and e2e tests, along with information on how this relates to frontend testing.


How to Test React Components in Isolation with Storybook
A guide and tutorial on how to test React components in isolation using Storybook. This includes guide uses a 'React counter' for code examples, and discusses various advantages of using Storybook.


TypeScript Unit Tests with Debugging
A short guide on how to set up TypeScript unit tests with debugging on VsCode, allowing you to set breakpoints on your unit tests.


Visual Regressions and How to Prevent Them
An overview of visual regression testing, where it fits into the testing hierarchy and the trade-offs of employing it as part of your testing strategy.
