在 Express 代码的 Mocha 测试中编码 JSON POST 数据

Question

我的 Express 代码在从 Postman 调用时运行良好，但在从 Mocha 调用时运行不正常。这让我相信我的 Mocha 测试没有在 POST 请求的 header 中正确设置数据（我对无参数 GET 或 POST 没有问题，对带参数的 GET 也没有问题; 只有带参数的 POST).

这是简单的代码，虽然我不会专注于此，因为它来自 Postman：

const app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

// Our unit tests send POST data in JSON format
app.use(express.json());


// Helper function - common code
function ResplyWithSentence(object, adjective)
{
  console.log('GET requestuest received: object = ' + object + '; adjective = ' + adjective);

  let sentence = softwareUnderTest.MakeAsentence(object, adjective);
  sentence = JSON.stringify(sentence);
  response.status(200);
  response.set('Content-Type', 'text/json');
  response.send( sentence );
}


// Handling POST request with parameters
app.post("/makeSentenceParamsPost", (request, response) => {
  const object    = request.body.object;
  const adjective = request.body.adjective;

  ResplyWithSentence(object, adjective);
})

这是 Postman 发送的内容：

POST /makeSentenceParamsPost HTTP/1.1
Host: localhost:3000
Content-Type: application/json
Cache-Control: no-cache
Postman-Token: 88dfc7cc-427e-3248-ba93-286083d4c18d

{
    "object": "cat",
    "adjective": "sleepy"
}

这是摩卡咖啡：

    it('should handle a POST request with parameters', async function(){
        var xhttp = new XMLHttpRequest();
        xhttp.open("POST", "http://localhost:3000/makeSentenceParamsPost", false);      // false === synchronous/blocking
        xhttp.setRequestHeader("Content-type", "application/json");

        const object = 'hubris';
        const adjective = 'pervasive';
        let   postParameters = {'object': object,
                                'adjective': adjective};

        xhttp.onreadystatechange = function(done) {
            while(this.readyState != 4) ;       // wait until "request finished and response is ready"

            assert.isObject(this);
            assert(this.status == 200);

            assert(JSON.parse(this.responseText)['sentence'] == `The ${object} is ${adjective}`);
            done();
    };

    postParameters = JSON.stringify(postParameters);
    xhttp.send(postParameters);
});

收到的回复是The undefined is undefined.

谁能告诉我我做错了什么？或者甚至如何调试它？

Answer 1

使用现代JavaScript!

我建议研究一下 fetch。它是 ES5 的等价物并使用 Promises。它更具可读性和易于定制。

const fetch = require("node-fetch");

const first = 'hubris'; // can't use words like object, these are reserved.
const second = 'pervasive';
let postParameters = {'first': first,
                                'second': second};
const url = "http://example.com";
fetch(url, {
    method : "POST",
    body: postParameters,
    // -- or --
    // body : JSON.stringify({
        // user : document.getElementById('user').value,
        // ...
    // })
}).then(
    response => response.text() // .json(), etc.
    
        assert.isObject(this);
        assert(this.status == 200);
        assert(JSON.parse(this.responseText)['sentence'] == `The ${object} is ${adjective}`);
        done();
);

Answer 2

类型上的大写 T 解决了问题：

xhttp.setRequestHeader("Content-Type", "application/json");

在 Express 代码的 Mocha 测试中编码 JSON POST 数据

Encoding JSON POST data in Mocha test of Express code

javascript

mocha.js

express