* Implements ES5 [`Array#forEach()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach) method.<br><br>
* Executes the provided callback once for each element.<br>
* Callbacks are run concurrently,
* and are only invoked for properties of the array that have been initialized (including those initialized with *undefined*), for unassigned ones `callback` is not run.<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with undefined value.
*/
export const forEach = async <T>(array: T[], callback: Function, thisArg?: T) => {
const promiseArray = []
for (let i = 0; i < array.length; i++) {
if (i in array) {
const p = Promise.resolve(array[i]).then((currentValue) => {
return callback.call(thisArg || this, currentValue, i, array)
})
promiseArray.push(p)
}
}
await Promise.all(promiseArray)
}
* Same functionality as [`forEach()`](global.html#forEach), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with undefined value.
*/
export const forEachSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
for (let i = 0; i < array.length; i++) {
if (i in array) {
await callback.call(thisArg || this, await array[i], i, array)
}
}
}
* Implements ES5 [`Array#map()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map) method.<br><br>
* Creates a new array with the results of calling the provided callback once for each element.<br>
* Callbacks are run concurrently,
* and are only invoked for properties of the array that have been initialized (including those initialized with *undefined*), for unassigned ones`callback` is not run.<br>
* Resultant *Array* is always the same *length* as the original one.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the resultant *Array* as value.
*/
export const map = async <T>(array: T[], callback: Function, thisArg?: T) => {
const promiseArray = []
for (let i = 0; i < array.length; i++) {
if (i in array) {
promiseArray[i] = Promise.resolve(array[i]).then((currentValue) => {
return callback.call(thisArg || this, currentValue, i, array)
})
}
}
return Promise.all(promiseArray)
}
* Same functionality as [`map()`](global.html#map), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the resultant *Array* as value.
*/
export const mapSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
const result = []
for (let i = 0; i < array.length; i++) {
if (i in array) {
result[i] = await callback.call(thisArg || this, await array[i], i, array)
}
}
return result
}
* Implements ES5 [`Array#find()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find) method.<br><br>
* Returns the value of the element that satisfies the provided `callback`. The value returned is the one found first.<br>
* Callbacks are run concurrently, meaning that all the callbacks are going to run even if the returned value is found in one of the first elements of `array`,
* depending on the async calls you are going to use, consider using instead [`findSeries()`](global.html#findSeries).<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the element that passed the test as value, otherwise *undefined*.
*/
export const find = <T>(array: T[], callback: Function, thisArg?: T) => {
return new Promise<T | undefined>((resolve, reject) => {
if (array.length === 0) {
return resolve(undefined)
}
let counter = 1
for (let i = 0; i < array.length; i++) {
const check = (found: T) => {
if (found) {
resolve(array[i])
} else if (counter === array.length) {
resolve(undefined)
}
counter++
}
Promise.resolve(array[i])
.then((elem) => callback.call(thisArg || this, elem, i, array))
.then(check)
.catch(reject)
}
})
}
* Same functionality as [`find()`](global.html#find), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the element that passed the test as value, otherwise *undefined*.
*/
export const findSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
for (let i = 0; i < array.length; i++) {
if (await callback.call(thisArg || this, await array[i], i, array)) {
return array[i]
}
}
}
* Implements ES5 [`Array#findIndex()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex) method.<br><br>
* Returns the index of the element that satisfies the provided `callback`. The index returned is the one found first.<br>
* Callbacks are run concurrently, meaning that all the callbacks are going to run even if the returned index is found in one of the first elements of `array`,
* depending on the async calls you are going to use, consider using instead [`findSeries()`](global.html#findSeries).<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the index that passed the test as value, otherwise *-1*.
*/
export const findIndex = <T>(array: T[], callback: Function, thisArg?: T) => {
return new Promise((resolve, reject) => {
if (array.length === 0) {
return resolve(-1)
}
let counter = 1
for (let i = 0; i < array.length; i++) {
const check = (found: T) => {
if (found) {
resolve(i)
} else if (counter === array.length) {
resolve(-1)
}
counter++
}
Promise.resolve(array[i])
.then((elem) => callback.call(thisArg || this, elem, i, array))
.then(check)
.catch(reject)
}
})
}
* Same functionality as [`findIndex()`](global.html#findIndex), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the index that passed the test, otherwise *-1*.
*/
export const findIndexSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
for (let i = 0; i < array.length; i++) {
if (await callback.call(thisArg || this, await array[i], i, array)) {
return i
}
}
}
* Implements ES5 [`Array#some()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some) method.<br><br>
* Test if some element in `array` passes the test implemented in `callback`.<br>
* Callbacks are run concurrently, meaning that all the callbacks are going to run even if some of the first elements pass the test,
* depending on the async calls you are going to use, consider using instead [`someSeries()`](global.html#someSeries).<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with *true* as value if some element passed the test, otherwise *false*.
*/
export const some = <T>(array: T[], callback: Function, thisArg?: T) => {
return new Promise((resolve, reject) => {
if (array.length === 0) {
return resolve(false)
}
let counter = 1
for (let i = 0; i < array.length; i++) {
if (!(i in array)) {
counter++
continue
}
const check = (found: T) => {
if (found) {
resolve(true)
} else if (counter === array.length) {
resolve(false)
}
counter++
}
Promise.resolve(array[i])
.then((elem) => callback.call(thisArg || this, elem, i, array))
.then(check)
.catch(reject)
}
})
}
* Same functionality as [`some()`](global.html#some), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with *true* as value if some element passed the test, otherwise *false*.
*/
export const someSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
for (let i = 0; i < array.length; i++) {
if (i in array && await callback.call(thisArg || this, await array[i], i, array)) {
return true
}
}
return false
}
* Implements ES5 [`Array#every()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every) method.<br><br>
* Test if all elements in `array` pass the test implemented in `callback`.<br>
* Callbacks are run concurrently, meaning that all the callbacks are going to run even if any of the first elements do not pass the test,
* depending on the async calls you are going to use, consider using instead [`everySeries()`](global.html#everySeries).<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with *true* as value if all elements passed the test, otherwise *false*.
*/
export const every = <T>(array: T[], callback: Function, thisArg?: T) => {
return new Promise<boolean>((resolve, reject) => {
if (array.length === 0) {
return resolve(true)
}
let counter = 1
for (let i = 0; i < array.length; i++) {
if (!(i in array)) {
counter++
continue
}
const check = (found: T) => {
if (!found) {
resolve(false)
} else if (counter === array.length) {
resolve(true)
}
counter++
}
Promise.resolve(array[i])
.then((elem) => callback.call(thisArg || this, elem, i, array))
.then(check)
.catch(reject)
}
})
}
* Same functionality as [`every()`](global.html#every), but runs only one callback at a time.<br><br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with *true* as value if all elements passed the test, otherwise *false*.
*/
export const everySeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
for (let i = 0; i < array.length; i++) {
if (i in array && !await callback.call(thisArg || this, await array[i], i, array)) {
return false
}
}
return true
}
* Implements ES5 [`Array#filter()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter) method.<br><br>
* Creates a new array with the elements that passed the test implemented in `callback`.<br>
* Callbacks are run concurrently.<br>
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @param {Object} [thisArg] - Value to use as *this* when executing the `callback`.
* @return {Promise} - Returns a Promise with the resultant filtered *Array* as value.
*/
export const filter = <T>(array: T[], callback: Function, thisArg?: T) => {
* while keeping the order of the elements
* (if you find a better way to do it please send a PR!)
*/
return new Promise((resolve, reject) => {
const promiseArray: Promise<T>[] = []
for (let i = 0; i < array.length; i++) {
if (i in array) {
promiseArray[i] = Promise.resolve(array[i]).then((currentValue) => {
return callback.call(thisArg || this, currentValue, i, array)
}).catch(reject)
}
}
return Promise.all(
promiseArray.map(async (p, i) => {
if (await p) {
return await array[i]
}
return undefined
})).then((result) => result.filter((val) => typeof val !== 'undefined')
).then(resolve, reject)
})
}
* Same functionality as [`filter()`](global.html#filter), but runs only one callback at a time.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts three arguments: `currentValue`, `index` and `array`.
* @return {Promise} - Returns a Promise with the resultant filtered *Array* as value.
*/
export const filterSeries = async <T>(array: T[], callback: Function, thisArg?: T) => {
const result = []
for (let i = 0; i < array.length; i++) {
if (i in array && await callback.call(thisArg || this, await array[i], i, array)) {
result.push(await array[i])
}
}
return result
}
* Implements ES5 [`Array#reduce()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce) method.<br><br>
* Applies a `callback` against an accumulator and each element in `array`.
* @param {Array} array - Array to iterate over.
* @param {Function} callback - Function to apply each item in `array`. Accepts four arguments: `accumulator`, `currentValue`, `currentIndex` and `array`.
* @param {Object} [initialValue] - Used as first argument to the first call of `callback`.
* @return {Promise} - Returns a Promise with the resultant value from the reduction.
*/
export const reduce = async <T>(array: T[], callback: Function, initialValue?: T) => {
if (array.length === 0 && initialValue === undefined) {
throw TypeError('Reduce of empty array with no initial value')
}
let i
let previousValue
if (initialValue !== undefined) {
previousValue = initialValue
i = 0
} else {
previousValue = array[0]
i = 1
}
for (i; i < array.length; i++) {
if (i in array) {
previousValue = await callback(await previousValue, await array[i], i, array)
}
}
return previousValue
}