'use strict';

const request = require('supertest');

const Koa = require('../..').server;

describe('app.use(fn)', function () {
  it('should compose middleware', function (done) {
    const app = new Koa();
    const calls = [];

    app.use(function * (next) {
      calls.push(1);
      yield next;
      calls.push(6);
    });

    app.use(function * (next) {
      calls.push(2);
      yield next;
      calls.push(5);
    });

    app.use(function * (next) {
      calls.push(3);
      yield next;
      calls.push(4);
    });

    const server = app.listen();

    request(server)
      .get('/')
      .expect(404)
      .end(function (err) {
        if (err) {
          return done(err);
        }
        calls.should.eql([1, 2, 3, 4, 5, 6]);
        done();
      });
  });

  it('should error when a non-generator function is passed', function () {
    const app = new Koa();

    try {
      app.use(function () {});
    } catch (err) {
      err.message.should.equal('app.use() requires a generator function');
    }
  });

  it('should not error when a non-generator function is passed when .experimental=true', function () {
    const app = new Koa();
    app.experimental = true;
    app.use(function () {});
  });
});