What is [[ Scopes ]] in dispatch() of redux

In JavaScript, when dealing with closures or function calls, you may observe an internal property named [[Scopes]] in the debugger. The [[Scopes]] property contains a hierarchical list of lexical environments for the current execution context, where captured variables and function definitions are stored. In the context of Redux's dispatch() function, the [[Scopes]] property applies similarly. When defining a dispatch() in Redux, it may access variables from the external scope, such as middleware, enhancers, or the Redux store itself. References to these external variables are stored in [[Scopes]] to access the correct data and resources during function execution. ### Example Suppose you have a Redux middleware that adds additional logging during dispatch() calls: javascript function loggerMiddleware(store) { return function(next) { return function(action) { console.log('dispatching', action); let result = next(action); console.log('next state', store.getState()); return result; }; }; } In this middleware's dispatch() function, the store and next variables are captured from the outer function. When you break on a breakpoint in the browser's JavaScript debugger and inspect this function, you typically find that these captured variables are stored in the [[Scopes]] property. The [[Scopes]] property allows dispatch() to correctly reference the store and next variables during execution, even though they are defined in the outer function. This is a typical application of JavaScript closures and a common pattern in the Redux architecture to ensure functions can access the necessary resources and data within their execution context.