Question

您好我在尝试使用express，mocha，chai和johnny-five来学习一些测试驱动开发。所以我写了这个小应用程序，可以打开和关闭LED。应用程序工作，但我的测试失败。有人可以告诉我在测试中我做错了什么吗？谢谢

npm test的输出是

> blink@1.0.0 test /Users/me/Documents/johnny-five/blink
> mocha --reporter spec
1435257445439 Looking for connected device
  j5
    .on()
      1) Should turn a led on
    .off()
      ✓ Should turn a led off
  1 passing (13ms)
  1 failing
  1) j5 .on() Should turn a led on:
     AssertionError: expected undefined to equal 1
      at Context.<anonymous> (test/j5.js:9:14)
npm ERR! Test failed.  See above for more details.

这是test / j5.js

require('mocha');
var assert =  require('chai').assert;
var j5 = require("../j5");

describe('j5', function () {
  describe('.on()', function () {
    it('Should turn a led on',function(){
      var result = j5.on();
      assert.equal(result, 1);
    });
  });

  describe('.off()', function () {
    it('Should turn a led off', function () {
      // var res = j5.on();
      // expect(res).to.equal(0);
    });
  });
});

这是server.js

var express = require("express");
var app = express();
var j5 = require("./j5");
var port = 3000;
app.get('/', function(req, res){
  res.send('hello j5');
});
app.get("/on", function(req, res) {
  j5.on();
  res.send("on");
});
app.get("/off", function(req, res) {
  j5.off();
  res.send("off");
});
console.log("listening on port http://localhost:" + port);
app.listen(3000);

这是j5.js

var exports = module.exports = {};
var five = require("johnny-five");
var board = new five.Board();
var board_ready = false;
var led = null;
board.on("ready", function() {
  board_ready = true;
  led = new five.Led(13);
});
exports.on = function() {
  if (led !== null && board_ready === true) {
    led.on();
    return 1;
  }
};
exports.off = function() {
  if (led !== null && board_ready === true) {
    led.off();
    return 0;
  }
};

编辑： test / j5.js中j5.js的路径错误。但现在我有一个新的错误。 AssertionError：在Context上预期undefined等于1。（试验/ j5.js：9：14）。

Answer 1

经过一番游戏，我发现了自己的错误 johnny-five需要一些时间通过串口连接到电路板。只要REPL中的构建可用，我就可以使用函数on()和off()。所以我在进行j5.on()调用之前等待了5秒。 done()函数的标准最大超时为2000毫秒。为了延长这段时间，我使用了this.timeout(10000);

这是我的新测试/ j5.js

require('mocha');
var assert = require('chai').assert;
var j5 = require("../j5");
var result = null;
describe('j5', function() {
  describe('.on()', function() {
    it('Should turn a led on', function(done) {
      this.timeout(10000);
      setTimeout(function() {
        result = j5.on();
        assert.equal(result, 1);
        done();
      }, 5000);
    });
  });
});

npm test的结果：

> blink@1.0.0 test /Users/icke/Documents/johnny-five/blink
> mocha --reporter spec
1435305595110 Device(s) /dev/cu.usbmodem1421
1435305595124 Connected /dev/cu.usbmodem1421
  j5
    .on()
1435305598694 Repl Initialized
      ✓ Should turn a led on (5003ms)
    .off()
      ✓ Should turn a led off


  2 passing (5s)

用Chai，Mocha，Express，johnny-five和node编写测试时的新手错误

1 个答案: