Array Move Multiple

Move multiple items in an array to a new position.

Install via npm

npm install array-move-multiple --save

Usage

Move by index

const { arrayMoveByIndex } = require('array-move-multiple');

const numbers = [0, 1, 2, 3, 4, 5];

describe('Move items by index', () => {
  test('moving to the beginning of the array', () => {
    expect(arrayMoveByIndex(numbers, [1, 2], 0)).toEqual([1, 2, 0, 3, 4, 5]);
    expect(arrayMoveByIndex(numbers, [1, 5], 0)).toEqual([1, 5, 0, 2, 3, 4]);
    expect(arrayMoveByIndex(numbers, [3, 5], 0)).toEqual([3, 5, 0, 1, 2, 4]);
  });

  test('moving to the end of the array', () => {
    expect(arrayMoveByIndex(numbers, [1, 2], 5)).toEqual([0, 3, 4, 5, 1, 2]);
    expect(arrayMoveByIndex(numbers, [1, 5], 5)).toEqual([0, 2, 3, 4, 1, 5]);
    expect(arrayMoveByIndex(numbers, [3, 5], 5)).toEqual([0, 1, 2, 4, 3, 5]);
  });

  test('moving to the middle of the array', () => {
    expect(arrayMoveByIndex(numbers, [1, 2], 2)).toEqual([0, 3, 1, 2, 4, 5]);
    expect(arrayMoveByIndex(numbers, [1, 5], 2)).toEqual([0, 2, 1, 5, 3, 4]);
    expect(arrayMoveByIndex(numbers, [3, 5], 2)).toEqual([0, 1, 3, 5, 2, 4]);
  });
});

Move by value with the default comparator

The default comparator uses === to find the index for a value.

const { arrayMoveByValue } = require('array-move-multiple');

const todo1 = { id: 1, isCompleted: true, name: 'Todo 1' };
const todo2 = { id: 2, isCompleted: true, name: 'Todo 2' };
const todo3 = { id: 3, isCompleted: false, name: 'Todo 3' };
const todo4 = { id: 4, isCompleted: false, name: 'Todo 4' };
const todo5 = { id: 5, isCompleted: false, name: 'Todo 5' };

const todos = [todo1, todo2, todo3, todo4, todo5];

describe('Move items by value', () => {
  test('with the default comparator', () => {
    expect(arrayMoveByValue(todos, [todo1, todo5], 2)).toEqual([
      todo2,
      todo3,
      todo1,
      todo5,
      todo4,
    ]);
  });
});

Move by value using compareBy

You can use a default comparator to tell arrayMoveByValue how to compare items when looking for their index.

const { arrayMoveByValue } = require('array-move-multiple');

const todo1 = { id: 1, isCompleted: true, name: 'Todo 1' };
const todo2 = { id: 2, isCompleted: true, name: 'Todo 2' };
const todo3 = { id: 3, isCompleted: false, name: 'Todo 3' };
const todo4 = { id: 4, isCompleted: false, name: 'Todo 4' };
const todo5 = { id: 5, isCompleted: false, name: 'Todo 5' };

const todos = [todo1, todo2, todo3, todo4, todo5];

describe('Move items by value', () => {
  test('using compareBy', () => {
    const compareBy = value => value.id;

    expect(
      arrayMoveByValue(todos, [{ id: 1 }, { id: 5 }], 2, { compareBy }),
    ).toEqual([todo2, todo3, todo1, todo5, todo4]);
  });
});

Move by values using compareBy and useValues

const { arrayMoveByValue } = require('array-move-multiple');

const todo1 = { id: 1, isCompleted: true, name: 'Todo 1' };
const todo2 = { id: 2, isCompleted: true, name: 'Todo 2' };
const todo3 = { id: 3, isCompleted: false, name: 'Todo 3' };
const todo4 = { id: 4, isCompleted: false, name: 'Todo 4' };
const todo5 = { id: 5, isCompleted: false, name: 'Todo 5' };
const todoAddLater = { id: 5, isCompleted: false, name: 'Todo 5' };

const todos = [todo1, todo2, todo3, todo4, todo5];

describe('Move items by value', () => {
  test('using compareBy and useValues', () => {
    const compareBy = value => value.id;

    expect(
      arrayMoveByValue(todos, [todo1, todo5, todoAddLater], 2, {
        compareBy,
        useValues: true,
      }),
    ).toEqual([todo2, todo3, todo1, todo5, todoAddLater, todo4]);
  });
});