export const emptyObject: Record<string, any> = Object.freeze({})
|
|
export const isArray = Array.isArray
|
|
// These helpers produce better VM code in JS engines due to their
|
// explicitness and function inlining.
|
export function isUndef(v: any): v is undefined | null {
|
return v === undefined || v === null
|
}
|
|
export function isDef<T>(v: T): v is NonNullable<T> {
|
return v !== undefined && v !== null
|
}
|
|
export function isTrue(v: any): boolean {
|
return v === true
|
}
|
|
export function isFalse(v: any): boolean {
|
return v === false
|
}
|
|
/**
|
* Check if value is primitive.
|
*/
|
export function isPrimitive(value: any): boolean {
|
return (
|
typeof value === 'string' ||
|
typeof value === 'number' ||
|
// $flow-disable-line
|
typeof value === 'symbol' ||
|
typeof value === 'boolean'
|
)
|
}
|
|
export function isFunction(value: any): value is (...args: any[]) => any {
|
return typeof value === 'function'
|
}
|
|
/**
|
* Quick object check - this is primarily used to tell
|
* objects from primitive values when we know the value
|
* is a JSON-compliant type.
|
*/
|
export function isObject(obj: any): boolean {
|
return obj !== null && typeof obj === 'object'
|
}
|
|
/**
|
* Get the raw type string of a value, e.g., [object Object].
|
*/
|
const _toString = Object.prototype.toString
|
|
export function toRawType(value: any): string {
|
return _toString.call(value).slice(8, -1)
|
}
|
|
/**
|
* Strict object type check. Only returns true
|
* for plain JavaScript objects.
|
*/
|
export function isPlainObject(obj: any): boolean {
|
return _toString.call(obj) === '[object Object]'
|
}
|
|
export function isRegExp(v: any): v is RegExp {
|
return _toString.call(v) === '[object RegExp]'
|
}
|
|
/**
|
* Check if val is a valid array index.
|
*/
|
export function isValidArrayIndex(val: any): boolean {
|
const n = parseFloat(String(val))
|
return n >= 0 && Math.floor(n) === n && isFinite(val)
|
}
|
|
export function isPromise(val: any): val is Promise<any> {
|
return (
|
isDef(val) &&
|
typeof val.then === 'function' &&
|
typeof val.catch === 'function'
|
)
|
}
|
|
/**
|
* Convert a value to a string that is actually rendered.
|
*/
|
export function toString(val: any): string {
|
return val == null
|
? ''
|
: Array.isArray(val) || (isPlainObject(val) && val.toString === _toString)
|
? JSON.stringify(val, replacer, 2)
|
: String(val)
|
}
|
|
function replacer(_key: string, val: any): any {
|
// avoid circular deps from v3
|
if (val && val.__v_isRef) {
|
return val.value
|
}
|
return val
|
}
|
|
/**
|
* Convert an input value to a number for persistence.
|
* If the conversion fails, return original string.
|
*/
|
export function toNumber(val: string): number | string {
|
const n = parseFloat(val)
|
return isNaN(n) ? val : n
|
}
|
|
/**
|
* Make a map and return a function for checking if a key
|
* is in that map.
|
*/
|
export function makeMap(
|
str: string,
|
expectsLowerCase?: boolean
|
): (key: string) => true | undefined {
|
const map = Object.create(null)
|
const list: Array<string> = str.split(',')
|
for (let i = 0; i < list.length; i++) {
|
map[list[i]] = true
|
}
|
return expectsLowerCase ? val => map[val.toLowerCase()] : val => map[val]
|
}
|
|
/**
|
* Check if a tag is a built-in tag.
|
*/
|
export const isBuiltInTag = makeMap('slot,component', true)
|
|
/**
|
* Check if an attribute is a reserved attribute.
|
*/
|
export const isReservedAttribute = makeMap('key,ref,slot,slot-scope,is')
|
|
/**
|
* Remove an item from an array.
|
*/
|
export function remove(arr: Array<any>, item: any): Array<any> | void {
|
const len = arr.length
|
if (len) {
|
// fast path for the only / last item
|
if (item === arr[len - 1]) {
|
arr.length = len - 1
|
return
|
}
|
const index = arr.indexOf(item)
|
if (index > -1) {
|
return arr.splice(index, 1)
|
}
|
}
|
}
|
|
/**
|
* Check whether an object has the property.
|
*/
|
const hasOwnProperty = Object.prototype.hasOwnProperty
|
export function hasOwn(obj: Object | Array<any>, key: string): boolean {
|
return hasOwnProperty.call(obj, key)
|
}
|
|
/**
|
* Create a cached version of a pure function.
|
*/
|
export function cached<R>(fn: (str: string) => R): (sr: string) => R {
|
const cache: Record<string, R> = Object.create(null)
|
return function cachedFn(str: string) {
|
const hit = cache[str]
|
return hit || (cache[str] = fn(str))
|
}
|
}
|
|
/**
|
* Camelize a hyphen-delimited string.
|
*/
|
const camelizeRE = /-(\w)/g
|
export const camelize = cached((str: string): string => {
|
return str.replace(camelizeRE, (_, c) => (c ? c.toUpperCase() : ''))
|
})
|
|
/**
|
* Capitalize a string.
|
*/
|
export const capitalize = cached((str: string): string => {
|
return str.charAt(0).toUpperCase() + str.slice(1)
|
})
|
|
/**
|
* Hyphenate a camelCase string.
|
*/
|
const hyphenateRE = /\B([A-Z])/g
|
export const hyphenate = cached((str: string): string => {
|
return str.replace(hyphenateRE, '-$1').toLowerCase()
|
})
|
|
/**
|
* Simple bind polyfill for environments that do not support it,
|
* e.g., PhantomJS 1.x. Technically, we don't need this anymore
|
* since native bind is now performant enough in most browsers.
|
* But removing it would mean breaking code that was able to run in
|
* PhantomJS 1.x, so this must be kept for backward compatibility.
|
*/
|
|
/* istanbul ignore next */
|
function polyfillBind(fn: Function, ctx: Object): Function {
|
function boundFn(a: any) {
|
const l = arguments.length
|
return l
|
? l > 1
|
? fn.apply(ctx, arguments)
|
: fn.call(ctx, a)
|
: fn.call(ctx)
|
}
|
|
boundFn._length = fn.length
|
return boundFn
|
}
|
|
function nativeBind(fn: Function, ctx: Object): Function {
|
return fn.bind(ctx)
|
}
|
|
// @ts-expect-error bind cannot be `undefined`
|
export const bind = Function.prototype.bind ? nativeBind : polyfillBind
|
|
/**
|
* Convert an Array-like object to a real Array.
|
*/
|
export function toArray(list: any, start?: number): Array<any> {
|
start = start || 0
|
let i = list.length - start
|
const ret: Array<any> = new Array(i)
|
while (i--) {
|
ret[i] = list[i + start]
|
}
|
return ret
|
}
|
|
/**
|
* Mix properties into target object.
|
*/
|
export function extend(
|
to: Record<PropertyKey, any>,
|
_from?: Record<PropertyKey, any>
|
): Record<PropertyKey, any> {
|
for (const key in _from) {
|
to[key] = _from[key]
|
}
|
return to
|
}
|
|
/**
|
* Merge an Array of Objects into a single Object.
|
*/
|
export function toObject(arr: Array<any>): object {
|
const res = {}
|
for (let i = 0; i < arr.length; i++) {
|
if (arr[i]) {
|
extend(res, arr[i])
|
}
|
}
|
return res
|
}
|
|
/* eslint-disable no-unused-vars */
|
|
/**
|
* Perform no operation.
|
* Stubbing args to make Flow happy without leaving useless transpiled code
|
* with ...rest (https://flow.org/blog/2017/05/07/Strict-Function-Call-Arity/).
|
*/
|
export function noop(a?: any, b?: any, c?: any) {}
|
|
/**
|
* Always return false.
|
*/
|
export const no = (a?: any, b?: any, c?: any) => false
|
|
/* eslint-enable no-unused-vars */
|
|
/**
|
* Return the same value.
|
*/
|
export const identity = (_: any) => _
|
|
/**
|
* Generate a string containing static keys from compiler modules.
|
*/
|
export function genStaticKeys(
|
modules: Array<{ staticKeys?: string[] } /* ModuleOptions */>
|
): string {
|
return modules
|
.reduce<string[]>((keys, m) => keys.concat(m.staticKeys || []), [])
|
.join(',')
|
}
|
|
/**
|
* Check if two values are loosely equal - that is,
|
* if they are plain objects, do they have the same shape?
|
*/
|
export function looseEqual(a: any, b: any): boolean {
|
if (a === b) return true
|
const isObjectA = isObject(a)
|
const isObjectB = isObject(b)
|
if (isObjectA && isObjectB) {
|
try {
|
const isArrayA = Array.isArray(a)
|
const isArrayB = Array.isArray(b)
|
if (isArrayA && isArrayB) {
|
return (
|
a.length === b.length &&
|
a.every((e: any, i: any) => {
|
return looseEqual(e, b[i])
|
})
|
)
|
} else if (a instanceof Date && b instanceof Date) {
|
return a.getTime() === b.getTime()
|
} else if (!isArrayA && !isArrayB) {
|
const keysA = Object.keys(a)
|
const keysB = Object.keys(b)
|
return (
|
keysA.length === keysB.length &&
|
keysA.every(key => {
|
return looseEqual(a[key], b[key])
|
})
|
)
|
} else {
|
/* istanbul ignore next */
|
return false
|
}
|
} catch (e: any) {
|
/* istanbul ignore next */
|
return false
|
}
|
} else if (!isObjectA && !isObjectB) {
|
return String(a) === String(b)
|
} else {
|
return false
|
}
|
}
|
|
/**
|
* Return the first index at which a loosely equal value can be
|
* found in the array (if value is a plain object, the array must
|
* contain an object of the same shape), or -1 if it is not present.
|
*/
|
export function looseIndexOf(arr: Array<unknown>, val: unknown): number {
|
for (let i = 0; i < arr.length; i++) {
|
if (looseEqual(arr[i], val)) return i
|
}
|
return -1
|
}
|
|
/**
|
* Ensure a function is called only once.
|
*/
|
export function once<T extends (...args: any[]) => any>(fn: T): T {
|
let called = false
|
return function () {
|
if (!called) {
|
called = true
|
fn.apply(this, arguments as any)
|
}
|
} as any
|
}
|
|
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is#polyfill
|
export function hasChanged(x: unknown, y: unknown): boolean {
|
if (x === y) {
|
return x === 0 && 1 / x !== 1 / (y as number)
|
} else {
|
return x === x || y === y
|
}
|
}
|
