import { Request, Response, NextFunction } from 'express';
import { asyncRoute } from '../../src/asyncRoute';

function fakeArgs() {
  const next = jest.fn() as unknown as NextFunction;
  return { req: {} as Request, res: {} as Response, next };
}

describe('asyncRoute', () => {
  it('passes a rejected handler to next so Express can answer the request', async () => {
    const boom = new Error('relation "categories" does not exist');
    const { req, res, next } = fakeArgs();

    await asyncRoute(async () => { throw boom; })(req, res, next);

    expect(next).toHaveBeenCalledWith(boom);
  });

  it('passes a synchronous throw to next as well', async () => {
    const boom = new Error('sync failure');
    const { req, res, next } = fakeArgs();

    await asyncRoute(() => { throw boom; })(req, res, next);

    expect(next).toHaveBeenCalledWith(boom);
  });

  it('leaves a successful handler alone', async () => {
    const { req, res, next } = fakeArgs();

    await asyncRoute(async () => 'fine')(req, res, next);

    expect(next).not.toHaveBeenCalled();
  });

  it('forwards the same arguments it was given', async () => {
    const handler = jest.fn(async () => undefined);
    const { req, res, next } = fakeArgs();

    await asyncRoute(handler)(req, res, next);

    expect(handler).toHaveBeenCalledWith(req, res, next);
  });
});