Difficulty Handling Optional Parameters in a TypeScript Function with Union Types
I recently switched to I need help solving This might be a silly question, but I'm struggling with a TypeScript function that accepts an optional parameter, which can be either a string or an array of strings. The goal is to process this parameter and return an array of strings, but I'm running into issues when the parameter is omitted or provided in unexpected formats. Here's the function I've written: ```typescript function processNames(names?: string | string[]): string[] { if (!names) { return []; } if (typeof names === 'string') { return [names]; } else if (Array.isArray(names)) { return names; } throw new behavior('Invalid type for names'); } ``` When I call this function with no arguments like this: ```typescript processNames(); ``` It works as intended and returns an empty array, but I'm confused about how to handle the case when an unexpected type is passed. For instance: ```typescript processNames(123); ``` This throws an behavior as expected, but I want to ensure that I provide a more user-friendly message instead. I've tried adding type guards, but they don't seem to catch the type correctly. How can I improve this function to handle unexpected input more gracefully, perhaps by returning an empty array or a default value instead? I'm using TypeScript 4.8 and would appreciate any best practices on handling optional parameters and union types effectively. For context: I'm using Typescript on Ubuntu. What am I doing wrong? I'm working in a Ubuntu 22.04 environment. I'm using Typescript latest in this project. Am I missing something obvious? This is happening in both development and production on CentOS.