import { describe, expect, it } from '@jest/globals'
import { nucleotideCounts } from './nucleotide-count.ts'

describe('count all nucleotides in a strand', () => {
  it('empty strand', () => {
    const expected = {
      A: 0,
      C: 0,
      G: 0,
      T: 0,
    }
    expect(nucleotideCounts('')).toEqual(expected)
  })

  it('can count one nucleotide in single-character input', () => {
    const expected = {
      A: 0,
      C: 0,
      G: 1,
      T: 0,
    }
    expect(nucleotideCounts('G')).toEqual(expected)
  })

  it('strand with repeated nucleotide', () => {
    const expected = {
      A: 0,
      C: 0,
      G: 7,
      T: 0,
    }
    expect(nucleotideCounts('GGGGGGG')).toEqual(expected)
  })

  it('strand with multiple nucleotides', () => {
    const expected = {
      A: 20,
      C: 12,
      G: 17,
      T: 21,
    }
    expect(
      nucleotideCounts(
        'AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC'
      )
    ).toEqual(expected)
  })

  it('strand with invalid nucleotides', () => {
    const expected = 'Invalid nucleotide in strand'
    expect(() => {
      nucleotideCounts('AGXXACT')
    }).toThrow(expected)
  })
})