liquidjs/src/util/underscore.ts

import { Drop } from '../drop/drop'

export const toString = Object.prototype.toString
const toLowerCase = String.prototype.toLowerCase

export const hasOwnProperty = Object.hasOwnProperty

export function isString (value: any): value is string {
  return typeof value === 'string'
}

// eslint-disable-next-line @typescript-eslint/ban-types
export function isFunction (value: any): value is Function {
  return typeof value === 'function'
}

export function isPromise<T> (val: any): val is Promise<T> {
  return val && isFunction(val.then)
}

export function isIterator (val: any): val is IterableIterator<any> {
  return val && isFunction(val.next) && isFunction(val.throw) && isFunction(val.return)
}

export function promisify<T1, T2> (fn: (arg1: T1, cb: (err: Error | null, result: T2) => void) => void): (arg1: T1) => Promise<T2>;
export function promisify<T1, T2, T3> (fn: (arg1: T1, arg2: T2, cb: (err: Error | null, result: T3) => void) => void): (arg1: T1, arg2: T2) => Promise<T3>;
export function promisify (fn: any) {
  return function (...args: any[]) {
    return new Promise((resolve, reject) => {
      fn(...args, (err: Error, result: any) => {
        err ? reject(err) : resolve(result)
      })
    })
  }
}

export function stringify (value: any): string {
  value = toValue(value)
  if (isString(value)) return value
  if (isNil(value)) return ''
  if (isArray(value)) return value.map(x => stringify(x)).join('')
  return String(value)
}

export function toEnumerable<T = unknown> (val: any): T[] {
  val = toValue(val)
  if (isArray(val)) return val
  if (isString(val) && val.length > 0) return [val] as unknown as T[]
  if (isIterable(val)) return Array.from(val)
  if (isObject(val)) return Object.keys(val).map((key) => [key, val[key]]) as unknown as T[]
  return []
}

export function toArray (val: any) {
  val = toValue(val)
  if (isNil(val)) return []
  if (isArray(val)) return val
  return [ val ]
}

export function toValue (value: any): any {
  return (value instanceof Drop && isFunction(value.valueOf)) ? value.valueOf() : value
}

export function toNumber (value: any): number {
  return +toValue(value) || 0
}

export function isNumber (value: any): value is number {
  return typeof value === 'number'
}

export function toLiquid (value: any): any {
  if (value && isFunction(value.toLiquid)) return toLiquid(value.toLiquid())
  return value
}

export function isNil (value: any): boolean {
  return value == null
}

export function isUndefined (value: any): boolean {
  return value === undefined
}

export function isArray (value: any): value is any[] {
  // be compatible with IE 8
  return toString.call(value) === '[object Array]'
}

export function isArrayLike (value: any): value is any[] {
  return value && isNumber(value.length)
}

export function isIterable (value: any): value is Iterable<any> {
  return isObject(value) && Symbol.iterator in value
}

/*
 * Iterates over own enumerable string keyed properties of an object and invokes iteratee for each property.
 * The iteratee is invoked with three arguments: (value, key, object).
 * Iteratee functions may exit iteration early by explicitly returning false.
 * @param {Object} object The object to iterate over.
 * @param {Function} iteratee The function invoked per iteration.
 * @return {Object} Returns object.
 */
export function forOwn <T> (
  obj: Record<string, T> | undefined,
  iteratee: ((val: T, key: string, obj: {[key: string]: T}) => boolean | void)
) {
  obj = obj || {}
  for (const k in obj) {
    if (hasOwnProperty.call(obj, k)) {
      if (iteratee(obj[k], k, obj) === false) break
    }
  }
  return obj
}

export function last <T>(arr: T[]): T;
export function last (arr: string): string;
export function last (arr: any[] | string): any | string {
  return arr[arr.length - 1]
}

/*
 * Checks if value is the language type of Object.
 * (e.g. arrays, functions, objects, regexes, new Number(0), and new String(''))
 * @param {any} value The value to check.
 * @return {Boolean} Returns true if value is an object, else false.
 */
export function isObject (value: any): value is object {
  const type = typeof value
  return value !== null && (type === 'object' || type === 'function')
}

export function range (start: number, stop: number, step = 1) {
  const arr: number[] = []
  for (let i = start; i < stop; i += step) {
    arr.push(i)
  }
  return arr
}

export function padStart (str: any, length: number, ch = ' ') {
  return pad(str, length, ch, (str, ch) => ch + str)
}

export function padEnd (str: any, length: number, ch = ' ') {
  return pad(str, length, ch, (str, ch) => str + ch)
}

export function pad (str: any, length: number, ch: string, add: (str: string, ch: string) => string) {
  str = String(str)
  let n = length - str.length
  while (n-- > 0) str = add(str, ch)
  return str
}

export function identify<T> (val: T): T {
  return val
}

export function changeCase (str: string): string {
  const hasLowerCase = [...str].some(ch => ch >= 'a' && ch <= 'z')
  return hasLowerCase ? str.toUpperCase() : str.toLowerCase()
}

export function ellipsis (str: string, N: number): string {
  return str.length > N ? str.slice(0, N - 3) + '...' : str
}

// compare string in case-insensitive way, undefined values to the tail
export function caseInsensitiveCompare (a: any, b: any) {
  if (a == null && b == null) return 0
  if (a == null) return 1
  if (b == null) return -1
  a = toLowerCase.call(a)
  b = toLowerCase.call(b)
  if (a < b) return -1
  if (a > b) return 1
  return 0
}

export function argumentsToValue<F extends (...args: any) => any, T> (fn: F) {
  return function (this: T, ...args: Parameters<F>) { return fn.call(this, ...args.map(toValue)) }
}

export function argumentsToNumber<F extends (...args: any) => any, T> (fn: F) {
  return function (this: T, ...args: Parameters<F>) { return fn.call(this, ...args.map(toNumber)) }
}

export function escapeRegExp (text: string) {
  return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&')
}

/** Return an array containing unique elements from _array_. Works with nested arrays and objects. */
export function * strictUniq<T> (array: Array<T>): Generator<T> {
  const seen = new Set()

  for (const element of array) {
    const key = JSON.stringify(element)
    if (!seen.has(key)) {
      seen.add(key)
      yield element
    }
  }
}