SonarCloud, SonarLint, and SonarQube are tools for software development that help detect bugs and errors in code. This article is part of a series focused on common pitfalls and errors when writing React code using JavaScript or TypeScript. It covers issues with React Hooks, such as infinite loops caused by setting state in the top-level component, and bugs like the "tree falling in the forest" paradox where the state update is not actually updating the component's state due to incorrect usage of the `!` operator. The article also highlights how SonarLint can detect these issues early on and provide explanations for why they happen, helping developers prevent problems before they occur.