sort-by.ts

/**
 * Utility function to sort elements by some nested property or another calculated value. Meant to fix JavaScript
 * missing a built-in `sortedBy` function like Kotlin has.
 * @example
 *  people.sort(by(person => person.age))
 * @param accessor a function that should return the value to sort by if called on an element
 */
export const by: <T>(accessor: (element: T) => string | number) => (a: T, b: T) => number = (accessor) =>
  (a, b) => {
    const aValue = accessor(a)
    const bValue = accessor(b)
    if (aValue < bValue) {
      return -1
    }
    if (aValue > bValue) {
      return 1
    }
    return 0
  }