@helcor/move-in-array

Move an item by position in a list of positionated items.

API

Array moveInArray(list, opts)

• Array list - Current list of items.
• Object opts - Options.
  • string id - Element identifier to move.
  • number to - Position to move element.
  • string key - Optional element identifier key in the list. Default 'id'.
  • string positionKey - Optional element position identifier key in the list. Default 'position'.
• Returns Array - A new list with the updated items. If no update was made the same list is returned.

Example

Move element by id 'i1' from position 1 to 3 where the id key is '_id' and the position key is 'pos'.

const moveInArray = require('@helcor/move-in-array');

const list = [
  { _id: 'i0', pos: 0 },
  { _id: 'i1', pos: 1 },
  { _id: 'i2', pos: 2 },
  { _id: 'i3', pos: 3 },
  { _id: 'i4', pos: 4 }
];
const received = moveInArray(list, {
  id: 'i1',
  to: 3,
  key: '_id',
  positionKey: 'pos'
});
const expected = [
  { _id: 'i0', pos: 0 },
  { _id: 'i1', pos: 3 }, // moved down
  { _id: 'i2', pos: 1 }, // moved up
  { _id: 'i3', pos: 2 }, // moved up
  { _id: 'i4', pos: 4 }
];
expect(received).toEqual(expected);
expect(received).not.toBe(list);