import { describe, it, expect, vi, beforeEach } from 'vitest'
import { asyncHandler } from './asyncHandler'
import type { Request, Response, NextFunction } from 'express'

const mockReq = {} as Request
const mockRes = {} as Response
let mockNext: NextFunction

beforeEach(() => {
  mockNext = vi.fn() as unknown as NextFunction
})

describe('asyncHandler', () => {
  it('calls next with error when async handler throws', async () => {
    const error = new Error('boom')
    const handler = asyncHandler(async () => {
      throw error
    })
    await handler(mockReq, mockRes, mockNext)
    expect(mockNext).toHaveBeenCalledWith(error)
  })

  it('does not call next when handler resolves', async () => {
    const handler = asyncHandler(async () => {
      // success
    })
    await handler(mockReq, mockRes, mockNext)
    expect(mockNext).not.toHaveBeenCalled()
  })

  it('calls next with error when handler rejects', async () => {
    const error = new Error('rejected')
    const handler = asyncHandler(() => Promise.reject(error))
    await handler(mockReq, mockRes, mockNext)
    expect(mockNext).toHaveBeenCalledWith(error)
  })
})