koa-lite/test/application/use.js

'use strict';

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

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

    app.use((ctx, next) => {
      calls.push(1);
      return next().then(() => {
        calls.push(6);
      });
    });

    app.use((ctx, next) => {
      calls.push(2);
      return next().then(() => {
        calls.push(5);
      });
    });

    app.use((ctx, next) => {
      calls.push(3);
      return next().then(() => {
        calls.push(4);
      });
    });

    const server = app.listen();

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

  it('should compose mixed middleware', done => {
    process.once('deprecation', () => {}); // silence deprecation message
    const app = new Koa();
    const calls = [];

    app.use((ctx, next) => {
      calls.push(1);
      return next().then(() => {
        calls.push(6);
      });
    });

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

    app.use((ctx, next) => {
      calls.push(3);
      return next().then(() => {
        calls.push(4);
      });
    });

    const server = app.listen();

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

  // https://github.com/koajs/koa/pull/530#issuecomment-148138051
  it('should catch thrown errors in non-async functions', done => {
    const app = new Koa();

    app.use(ctx => ctx.throw('Not Found', 404));

    request(app.listen())
      .get('/')
      .expect(404)
      .end(done);
  });

  it('should accept both generator and function middleware', done => {
    process.once('deprecation', () => {}); // silence deprecation message
    const app = new Koa();

    app.use((ctx, next) => { return next(); });
    app.use(function *(next){ this.body = 'generator'; });

    request(app.listen())
      .get('/')
      .expect(200)
      .expect('generator', done);
  });

  it('should throw error for non function', () => {
    const app = new Koa();

    [null, undefined, 0, false, 'not a function'].forEach(v => (() => app.use(v)).should.throw('middleware must be a function!'));
  });

  it('should output deprecation message for generator functions', done => {
    process.once('deprecation', message => {
      assert(/Support for generators will been removed/.test(message));
      done();
    });

    const app = new Koa();
    app.use(function *(){});
  });

  it('should throw error for non function', () => {
    const app = new Koa();

    (() => app.use('not a function')).should.throw('middleware must be a function!');
  });
});