import { describe, it, expect } from 'vitest'
import { countLines } from '../../src/composables/useLineNumberEditor.js'

describe('useLineNumberEditor.countLines', () => {
  it('returns 1 for empty or whitespace-only text', () => {
    expect(countLines('')).toBe(1)
    expect(countLines(null)).toBe(1)
    expect(countLines(undefined)).toBe(1)
  })

  it('counts single line without trailing newline', () => {
    expect(countLines('hello')).toBe(1)
  })

  it('counts multiple lines', () => {
    expect(countLines('a\nb\nc')).toBe(3)
    expect(countLines('a\nb\n')).toBe(3)
  })
})