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

describe('palindrome', () => {
  it('should return 0 for sequence with only one element', () => {
    expect(palindrome(0, 1)).toBe(0)
    expect(palindrome(1, 1)).toBe(0)
    expect(palindrome(-1, 1)).toBe(0)
  })

  it('should map positive index to palindrome pattern', () => {
    expect(palindrome(0, 3)).toBe(0)
    expect(palindrome(1, 3)).toBe(1)
    expect(palindrome(2, 3)).toBe(2)
    expect(palindrome(3, 3)).toBe(1)
    expect(palindrome(4, 3)).toBe(0)
    expect(palindrome(5, 3)).toBe(1)
    expect(palindrome(6, 3)).toBe(2)
    expect(palindrome(7, 3)).toBe(1)
    expect(palindrome(8, 3)).toBe(0)
  })

  it('should map negative index to palindrome pattern', () => {
    expect(palindrome(-0, 3)).toBe(0)
    expect(palindrome(-1, 3)).toBe(1)
    expect(palindrome(-2, 3)).toBe(2)
    expect(palindrome(-3, 3)).toBe(1)
    expect(palindrome(-4, 3)).toBe(0)
    expect(palindrome(-5, 3)).toBe(1)
    expect(palindrome(-6, 3)).toBe(2)
    expect(palindrome(-7, 3)).toBe(1)
    expect(palindrome(-8, 3)).toBe(0)
  })
})