TypeScript Helper Functions for Sorting

I'm not a huge fan of the Array.sort() method in JavaScript. When I want to sort an array of some random data type based on non-trivial criteria, I find it tedious to write the body of the compareFn argument to derive a comparable value from each of two arguments, compare those values myself, and then return -1, 1, or 0 as appropriate.

Below are some helper functions I like to use when sorting complicated data in TypeScript. The first is a compare() function that takes care of returning -1, 1, or 0 based on the two input values, and the second is a generic sortBy() function that accepts an array and a function to derive a comparable value from each item in the array.

export function compare(a: number, b: number): number;
export function compare(a: string, b: string): number;
export function compare(a: any, b: any) {
    if (a < b) {
        return -1;
    } else if (a > b) {
        return 1;
    } else {
        return 0;
    }
}

export function sortBy<T>(array: T[], compareBy: ((arg: T) => number)): T[];
export function sortBy<T>(array: T[], compareBy: ((arg: T) => string)): T[];
export function sortBy<T>(array: T[], compareBy: ((arg: T) => any)) {
  return array.sort((a, b) => compare(compareBy(a), compareBy(b)));
}

Some notes:

• I've added function overloads so that the compare() function can only be used to compare either a pair of numbers or a pair of strings. Likewise, the sortBy() function has overloads that only accept compareBy arguments which return either numbers or strings.

• The sortBy() function passes the return value of array.sort(). This means that sortBy() sorts arrays in place and returns a reference to the input array. You may wish to implement a toSortedBy() function that uses Array.toSorted().