Async-Ray

Purpose of this package is to provide async/await callbacks for every, filter, find, findIndex, forEach, map, reduce, reduceRight and some methods in Array.

TypeScript Doc: https://rpgeeganage.github.io/async-ray/doc/

Content

• Basic Usage
• Supported methods
• Using methods individually
• Chaining

Basic usage

const { AsyncRay } = require('async-ray');

Supported methods

• .aEvery
• .aFilter
• .aFind
• .aFindIndex
• .aFlatMap
• .aForEach
• .aMap
• .aReduce
• .aReduceRight
• .aSome

.aEvery

.aEvery(async callback(element[, index[, array]]))

async function dummy(element, needle) {
  return Promise.resolve(element > needle);
}

const inputArray = [10, 20, 30, 40];

// Call Every method
const output = await AsyncRay(inputArray).aEvery(
  async (i, index, collection) => {
    // Dummy async function
    return await dummy(i, 5);
  }
);

console.log(output);
// Output is true

.aFilter

.aFilter(async callback(element[, index[, array]]))

async function dummy(element, needle) {
  return Promise.resolve(element > needle);
}

const inputArray = [1, 2, 3, 4];

// Call Filter method
const filterArray = await AsyncRay(inputArray).aFilter(
  async (i, index, collection) => {
    // Dummy async function
    return await dummy(i, 2);
  }
);

console.log(filterArray);
// Output is [3, 4]

.aFind

.aFind(async callback(element[, index[, array]]))

Find will return the found value or undefined

async function dummy(element, needle) {
  return Promise.resolve(element === needle);
}

const inputArray = [1, 2, 3, 4];

// Call Find method
const outputElement = await AsyncRay(inputArray).aFind(
  async (i, index, collection) => {
    return await dummy(i, 2);
  }
);

console.log('Output is ', outputElement);
// Output is 2

.aFindIndex

.aFindIndex(async callback(element[, index[, array]]))

FindIndex will return the index of found value or -1

async function dummy(element, needle) {
  return Promise.resolve(element === needle);
}

const inputArray = [1, 2, 3, 4];

// Call Find method
const outputIndex = await AsyncRay(inputArray).aFindIndex(
  async (i, index, collection) => {
    return await dummy(i, 2);
  }
);

console.log('Output is ', outputIndex);
// Output is 1

.aFlatMap

.aFlatMap(async callback(element[, index[, array]]))

async function dummy(element) {
  return Promise.resolve([element, element * 2]);
}

const inputArray = [1, 2, 3, 4];

// Call Map method
const flatMappedArray = await AsyncRay(inputArray).aFlatMap(
  async (i, index, collection) => {
    // Dummy async function
    return await dummy(i);
  }
);
console.log(flatMappedArray);
// Output is [1, 2, 2, 4, 3, 6, 4, 8]

.aForEach

.aForEach(async callback(element[, index[, array]]))

async function dummy(element) {
  return Promise.resolve(element);
}

const inputArray = [1, 2, 3, 4];
const outputArray = [];

// Call ForEach method
await AsyncRay(inputArray).aForEach(async (i, index, collection) => {
  outputArray.push(await dummy(i));
});

console.log('Output is ', outputArray);
// Output is [1, 2, 3, 4]

.aMap

.aMap(async callback(element[, index[, array]]))

async function dummy(element) {
  return Promise.resolve(element);
}

const inputArray = [1, 2, 3, 4];

// Call Map method
const mappedArray = await AsyncRay(inputArray).aMap(
  async (i, index, collection) => {
    // Dummy async function
    return await dummy(i);
  }
);
console.log(mappedArray);
// Output is [1, 2, 3, 4]

.aReduce

.aReduce(async callback(accumulator, element[, index[, array]]), [initialValue])

async function dummy(element) {
  return Promise.resolve(element);
}

const inputArray = [10, 20, 30, 40];

// Call Reduce method
const output = await AsyncRay(inputArray).aReduce(
  async (acc, i, index, collection) => {
    return acc + (await dummy(i));
  },
  1
);

console.log('Output is ', output);
// Output is 101

.aReduceRight

.aReduceRight(async callback(accumulator, element[, index[, array]]), [initialValue])

async function dummy(element) {
  return Promise.resolve(element);
}

const inputArray = [10, 20, 30, 40];

// Call Reduce method
const output = await AsyncRay(inputArray).aReduceRight(
  async (acc, i, index, collection) => {
    return acc + (await dummy(i));
  },
  1
);

console.log('Output is ', output);
// Output is 101

.aSome

.aSome(async callback(element[, index[, array]]))

async function dummy(element, needle) {
  return Promise.resolve(element > needle);
}

const inputArray = [10, 20, 30, 40];

// Call Some method
const output = await AsyncRay(inputArray).aSome(
  async (i, index, collection) => {
    // Dummy async function
    return await dummy(i, 30);
  }
);

console.log(output);
// Output is true

Using methods individually

You can use each method without creating AsyncRay object.

import {
  aEvery, aFilter, aFind, aFindIndex,
  aForEach, aMap, aReduce, aReduceRight, aSome
} from 'async-ray';

// aEvery
const everyResult = await aEvery(
  [1, 2, 3],
  async (e) => Promise.resolve(e > 0)
);

// aFilter
const filterResult = await aFilter(
  [1, 2, 3],
  async (e) => Promise.resolve(e > 1)
);

// aFind
const findResult = await aFind(
  [1, 2, 3],
  async (e) => Promise.resolve(e === 3)
);

// aFindIndex
const findIndexResult = await aFindIndex(
  [1, 2, 3],
  async (e) => Promise.resolve(e === 2)
);

// aForEach
const forEachResult: number[] = [];
await aForEach(
  [1, 2, 3],
  async (e) => {
    const op = await Promise.resolve(e * 10);
	  forEachResult.push(op);
  }
);

// aMap
const mapResult = await aMap(
  [1, 2, 3],
  async (e) => Promise.resolve(e * 10)
);

// aReduce
const reduceResult = await aReduce(
  [1, 2, 3],
  async (acc, e) => Promise.resolve(e + acc),
  0
);

// aReduceRight
const reduceRightResult = await aReduceRight(
  [1, 2, 3],
  async (acc, e) => Promise.resolve(e + acc),
  0
);

// aSome
const someResult = await aSome(
  [1, 2, 3],
  async (e) => Promise.resolve(e > 1)
);

Chaining

Async-Ray methods can be chained using Chain functionality

Basic usage

const { Chain } = require('async-ray');

---

Chaining will return an instance of Async-Ray if returned type is an array.

---

sample 1 - aMap() and aFilter()

(sample code)

---

The process() method must be called explicitly to process the chain because aMap() and aFilter() method returns an array.

const input = [1, 2, 3];

const op = await Chain(input)
  .aMap(
    async (e) => Promise.resolve(e * 10)
  )
  .aFilter(
    async (e) => Promise.resolve(e > 10)
  )
  .aMap(
    async (e) => Promise.resolve(e * 10)
  )
  // Call the process() method to execute the chain
  .process();

console.log('Output is ', op);
// Output is [ 200, 300 ]

sample 2 - aMap(), aFilter() and aFind()

(sample code)

---

The process() method should not be called because aFind() does not return an array.

const input = [1, 2, 3];

const op = await Chain(input)
  .aMap(
    async (e) => Promise.resolve(e * 10)
  )
  .aFilter(
    async (e) => Promise.resolve(e > 10)
  )
  .aMap(
    async (e) => Promise.resolve(e * 10)
  )
  .aFind(
    async (e) => Promise.resolve(e === 300)
  );
  // No need to call process() method

console.log('Output is ', op);
// Output is 300

Between other Array methods methods

---

Sample 1 - Async-Ray Chain with filter()

const input = [1, 2, 3];

const op = (
  await Chain(input)
    .aMap(
      async (e) => Promise.resolve(e * 10)
    )
    .aFilter(
      async (e) => Promise.resolve(e > 10)
    )
    .aMap(
      async (e) => Promise.resolve(e * 10)
    )
    .process()
)
.filter(e => e > 200)

console.log('Output is ', op);
// Output is [ 300 ]

---

Sample 2 - Async-Ray Chain with find()

const input = [1, 2, 3];

const op = (
    await Chain(input)
    .aMap(
      async (e) => Promise.resolve(e * 10)
    )
    .aFilter(
      async (e) => Promise.resolve(e > 10)
    )
    .aMap(
      async (e) => Promise.resolve(e * 10)
    )
    .process()
)
.find(e => e === 200)

console.log('Output is ', op);
// Output is 200