'use strict';

const request = require('supertest');
const Koa = require('../..');

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(){});
  })
})