Handling large nested arrays in TypeScript and ensuring type safety
I'm relatively new to this, so bear with me... I'm stuck on something that should probably be simple... I am working with a deeply nested array structure in TypeScript, and I need to ensure that I maintain type safety throughout the manipulation of this data. The arrays can have varying depths, and the data may not always adhere to the expected structure. For example, I have the following nested array: ```typescript const data: (string | string[])[][] = [ ["a", ["b", "c"]], ["d", ["e", "f"]], [["g", "h"]], ]; ``` My goal is to flatten this array into a single array of strings while preserving type safety. I attempted to use the `flat()` method, but I ran into a type behavior: ```typescript const flatData: string[] = data.flat(); // Type 'string | string[]' is not assignable to type 'string[]' ``` To resolve this, I tried using a recursive helper function to handle the flattening. Here's what I came up with: ```typescript function flattenArray(arr: (string | string[])[]): string[] { return arr.reduce((acc: string[], val) => { if (typeof val === 'string') { acc.push(val); } else if (Array.isArray(val)) { acc.push(...flattenArray(val)); } return acc; }, []); } ``` However, I still encounter a type scenario when I run this code. My TypeScript version is 4.5.2, and I'm using `strict` mode in my `tsconfig.json`. I suspect there might be a better way to ensure that this function works correctly without losing type safety. Is there a more idiomatic way to achieve this in TypeScript? Or are there best practices to follow when dealing with such nested arrays? Also, any tips on debugging type issues in TypeScript would be greatly appreciated! Is there a better approach?