StrictMode in React is a development tool that acts as a wrapper around a component tree. It does not render any visible UI but enables additional checks and warnings that help developers identify potential problems in their application during the development phase. StrictMode is particularly useful for catching issues related to the following:
Unsafe lifecycle methods: It helps detect the use of legacy lifecycle methods that are unsafe in asynchronous rendering, such as componentWillMount, componentWillReceiveProps, and componentWillUpdate, which are often a source of bugs and inconsistencies.
Deprecated API usage: It warns about the use of deprecated APIs like findDOMNode and the legacy string ref API, encouraging developers to transition to safer and more reliable alternatives.
Side effects: By intentionally double-invoking certain class component methods and functional component hooks (such as the constructor, render method, and setState updater functions) during mounting, unmounting, and updates, StrictMode helps identify components that produce side effects. This is particularly useful for ensuring that effects and cleanup functions are written correctly.
Detecting unexpected mutations: It helps detect if there are any unexpected mutations happening in the application, which can lead to inconsistent UI and hard-to-track-down bug...
