index.ts

import type { RoundingMethod } from '../../types'

type RoundingFn = typeof Math.round

type RoundingFnsMap = { [method in RoundingMethod]: RoundingFn }

const roundingMap: RoundingFnsMap = {
  ceil: Math.ceil,
  round: Math.round,
  floor: Math.floor,
  trunc: (value: number) => (value < 0 ? Math.ceil(value) : Math.floor(value)), // Math.trunc is not supported by IE
}

const defaultRoundingMethod: RoundingMethod = 'trunc'

export function getRoundingMethod(method: RoundingMethod | undefined) {
  return method ? roundingMap[method] : roundingMap[defaultRoundingMethod]
}