data-fns/src/lib/euclideanSequencer.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 { euclideanSequencer } from './euclideanSequencer'

describe('euclideanSequencer', () => {
  test('should return a sequence with notes spaced evenly', () => {
    expect(euclideanSequencer(8, 3)).toEqual([0, 2, 5])
  })

  test('should return a sequence with notes spaced as evenly as possible', () => {
    expect(euclideanSequencer(16, 5)).toEqual([0, 3, 6, 9, 12])
  })

  test('should return a sequence rotated by the optional rotation param', () => {
    expect(euclideanSequencer(8, 3, 1)).toEqual([1, 3, 6])
    expect(euclideanSequencer(8, 3, 3)).toEqual([0, 3, 5])
    expect(euclideanSequencer(8, 3, 4)).toEqual([1, 4, 6])
  })

  test('should return an empty sequence when steps or notes are 0', () => {
    expect(euclideanSequencer(0, 0)).toEqual([])
    expect(euclideanSequencer(0, 1)).toEqual([])
    expect(euclideanSequencer(1, 0)).toEqual([])
  })

  test('should return a sequence with all notes when notes equal steps', () => {
    expect(euclideanSequencer(4, 4)).toEqual([0, 1, 2, 3])
  })

  test('should return a sequence with all notes when notes is greater than steps', () => {
    expect(euclideanSequencer(3, 4)).toEqual([0, 1, 2])
  })

  test('should return an error message when inputs are negative', () => {
    expect(() => euclideanSequencer(-2, 3)).toThrowError('Inputs must be positive integers')
  })
})