TypeScript Issue with Union Types in Function Overloading for a Custom Hook in React
I keep running into I'm facing an issue with TypeScript while implementing a custom hook that uses function overloading..... My hook is supposed to accept either a string or an array of strings as an argument, but TypeScript seems to struggle with inferring the correct type in the overloaded function implementations. Here's the custom hook I'm trying to create: ```typescript import { useState } from 'react'; function useCustomHook(input: string): number; function useCustomHook(input: string[]): number[]; function useCustomHook(input: string | string[]): number | number[] { const [state, setState] = useState<number | number[]>([]); if (typeof input === 'string') { // Simulate processing a single string const result = input.length; setState(result); return result; } else { // Simulate processing an array of strings const results = input.map(item => item.length); setState(results); return results; } } ``` When I call `useCustomHook` with a string, it works fine and returns a number as expected. However, when I call it with an array of strings, TypeScript throws the following error: ``` Argument of type 'string[]' is not assignable to parameter of type 'string'. ``` I've tried to explicitly cast the input parameter in the implementation, like this: ```typescript function useCustomHook(input: string | string[]): number | number[] { const [state, setState] = useState<number | number[]>([]); if (Array.isArray(input)) { const results = input.map(item => item.length); setState(results); return results; } // other code... } ``` This still results in the same error. I've also checked my `tsconfig.json`, and it has `strict` mode enabled, which I suspect might be causing TypeScript to be extra cautious about type inference. How can I resolve this error and ensure that TypeScript recognizes the overloaded types properly? I'm using TypeScript version 4.5.2 and React 17.0.2. Any help would be greatly appreciated! Any pointers in the right direction? For reference, this is a production REST API. Is this even possible?