data-fns/src/lib/patternChunks.test.ts

This library provides utility functions for working with array data that are useful in many contexts, including creative coding. It offers generic functions that perform common operations such as offsetting an array, generating an array based on a callbac

import { patternChunks } from './patternChunks'

describe('patternChunks', () => {
  it('returns empty array when given empty array', () => {
    const result = patternChunks([], [1])
    expect(result).toEqual([])
  })

  it('returns array with single chunk when pattern is longer than array', () => {
    const result = patternChunks(['a', 'b', 'c'], [4])
    expect(result).toEqual([['a', 'b', 'c']])
  })

  it('creates subarrays of correct size according to pattern', () => {
    const array = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
    const pattern = [2, 3]
    const result = patternChunks(array, pattern)
    expect(result).toEqual([['a', 'b'], ['c', 'd', 'e'], ['f', 'g'], ['h', 'i', 'j']])
  })

  it('cycles pattern when pattern is shorter than array', () => {
    const array = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
    const pattern = [2, 3]
    const result = patternChunks(array, pattern)
    expect(result).toEqual([['a', 'b'], ['c', 'd', 'e'], ['f', 'g'], ['h', 'i', 'j']])
  })
})