export const noop = () => { }

export const identity = x => x

export const assign = <T, S>(tar: T, src: S): T & S => {

// @ts-ignore

for (const k in src) tar[k] = src[k]

return tar as T & S

}

export const isPromise = <T = any>(value: any): value is PromiseLike<T> => {

return value && typeof value === 'object' && typeof value.then === 'function'

}

export const run = (callback: any) => {

return callback()

}

export const blankObject = () => {

return Object.create(null)

}

export const runAll = (fns) => {

fns.forEach(run)

}

export const isFunction = (thing: any): thing is Function => {

return typeof thing === 'function'

}

export const safeNotEqual = (a, b) => {

return a != a ? b == b : a !== b || ((a && typeof a === 'object') || typeof a === 'function')

}

export const notEqual = (a, b) => {

return a != a ? b == b : a !== b

}

export const isEmpty = (obj) => {

return Object.keys(obj).length === 0

}

export const validateStore = (store, name) => {

if (store != null && typeof store.subscribe !== 'function')

throw new Error(`'${name}' is not a store with a 'subscribe' method`)

}

export const subscribe = (store, ...callbacks) => {

if (store == null)

return noop

const unsub = store.subscribe(...callbacks)

return unsub.unsubscribe ? () => unsub.unsubscribe() : unsub

}

export const getStoreValue = (store) => {

let value

subscribe(store, _ => value = _)()

return value

}

export const once = (fn) => {

let ran = false

return function (this: any, ...args) {

if (ran) return

ran = true

fn.call(this, ...args)

}

}

export const nullToEmpty = (value) => {

return value == null ? '' : value

}

export const hasProp = (obj, prop) => Object.prototype.hasOwnProperty.call(obj, prop)

export const actionDestroyer = (action_result) => {

return action_result && isFunction(action_result.destroy) ? action_result.destroy : noop

}