Lodash FP missing functions

lodashMissing.ts

/**
 * Returns true if item is defined
 * @example
 * isDefined('something') => true
 */
export const isDefined = (item: any): boolean => !isNil(item)

/**
 * Scales a value from a range to another range
 * @example
 * scale(1, [0, 1], [0, 100]) => 100
 * scale(5, [0, 10], [2, 4]) => 3
 */
export const scale = (
  value: number,
  startRange: number[],
  endRange: number[],
): number => {
  const result =
    ((value - startRange[0]) * (endRange[1] - endRange[0])) /
      (startRange[1] - startRange[0]) +
    endRange[0]
  return result || 0
}

/**
 * Rename a property in object
 * @example
 * rename('a', 'b', { a: 1 }) => { b: 1 }
 */
export const rename = (fromPath: string, toPath: string, object: Object): Object =>
  set(toPath, object[fromPath], omit([fromPath], object))

/**
 * Exchange value in fromPath key with value in toPath key
 * @example
 * trade('a', 'b', { a: 1, b: 2, c: 3 }) => { a: 2, b: 1, c: 3 }
 */
export const trade = (fromPath: string, toPath: string, object: Object): Object => {
  const fromValue = get(fromPath, object)
  return flow([rename(toPath, fromPath), set(toPath, fromValue)])(object)
}

/**
 * Returns array with value pushed at index
 * @example
 * insertAt(1, 9, [1, 2, 3]) => [1, 9, 2, 3]
 */
export const insertAt = (index: number, value: any, array: any[]): any[] => {
  if (index > array.length) {
    return array
  }
  
  return array.slice(0, index).concat(value, array.slice(index))
}

/**
 * Returns array without the value at index
 * @example
 * removeAt(1, [1, 2, 3]) => [1, 3]
 */
export const removeAt = (index: number, array: any[]): any[] =>
  array.slice(0, index).concat(array.slice(index + 1))

/**
 * Returns array with value at index replaced by another value
 * @example
 * replaceAt(1, 9, [1, 2, 3]) => [1, 9, 3]
 */
export const replaceAt = (
  index: number,
  value: any,
  array: any[],
): any[] => {
  if (index > array.length) {
    return array
  }

  return array.slice(0, index).concat(value, array.slice(index + 1))
}

/**
 * Returns true if array starts with the other array
 * @example
 * startsWith(['a', 'b'], ['a', 'b', 'c']) => true
 */
export const startsWith = (source: string[], target: string[]): boolean =>
  source.every((value, index) => value === target[index])

/**
 * Returns array with item at fromIndex moved to toIndex
 * @example
 * moveTo(1, 4, [1, 2, 3, 4, 5, 6]) => [1, 3, 4, 5, 2, 6]
 */
export const moveTo = (
  fromIndex: number,
  toIndex: number,
  array: any[],
): any[] => {
  // indexes are equals
  if (fromIndex === toIndex) {
    return array
  }

  const item = array[fromIndex]

  // move down
  if (fromIndex < toIndex) {
    return [
      ...array.slice(0, fromIndex),
      ...array.slice(fromIndex + 1, toIndex + 1),
      item,
      ...array.slice(toIndex + 1),
    ]
  }

  // move up
  return [
    ...array.slice(0, toIndex),
    item,
    ...array.slice(toIndex, fromIndex),
    ...array.slice(fromIndex + 1),
  ]
}