import { describe, expect, it } from 'vitest'
import { limiter } from './client'

describe('limiter', () => {
  it('runs at most n calls at once, all of them, failures included', async () => {
    const limit = limiter(2)
    let running = 0, peak = 0
    const call = (n: number) => limit(async () => {
      peak = Math.max(peak, ++running)
      await new Promise(r => setTimeout(r, 5))
      running--
      if (n === 2) throw new Error('503')
      return n
    })
    const out = await Promise.allSettled([1, 2, 3, 4, 5].map(call))
    expect(peak).toBe(2)
    expect(out.map(r => (r.status === 'fulfilled' ? r.value : 'x'))).toEqual([1, 'x', 3, 4, 5])
  })
})