使用NPM nock(主机名未定义)测试基本功能

Question

更新：我有一个基本的异步函数，我想单位测试。我正在使用NPM的nock来模拟服务器的响应。每次我运行这个小测试脚本时，我都会收到主机名不确定的错误：当我尝试从测试中调用功能时，我不明白为什么会遇到此错误。当我运行脚本以及在Postman中打电话时，它可以正常工作。我觉得我正在寻找超级基础的东西？

这是单元测试代码：

const assert = require('chai').assert;
const getSorted = require('../src/karma').getSorted;
const nock = require('nock');
describe('Sorting', function () {
    it('should return karma in DESC order', function (done) {
        let expectedKarmas = { users: ['nikki', 'person', 'nolan'], karmas: ['3', '2', '1'] }
        let karmaApi = nock(`http://server:4567/`);
        karmaApi.get('/getsorted/DESC')
            .reply(200,
                [['bmlra2k=', '3'], ['cGVyc29u', '2'], ['bm9sYW4=', '1']]
            );
        let recievedKarmas = getSorted("DESC");
        console.log('recievedKarmas:::', recievedKarmas)
        assert.equal(recievedKarmas, expectedKarmas);
    });
});

这是原始功能：

let axios = require("axios");
let atob = require('atob');
//end point is "server:4567"
let KARMABOT_API_ENDPOINT = process.env.KARMABOT_API_ENDPOINT;
module.exports = {
getSorted: async function (direction) {
        if (direction !== "ASC" && direction !== "DESC") {
            console.error("INVALID SORTING DIRECTION: %s. PLEASE PROVIDE ASC OR DESC", direction);
            return;
        }
        try {
            let url = `http://${KARMABOT_API_ENDPOINT}/getsorted/${direction}`;
            console.log('URL IS:', url)
            let jsonResult = await axios.get(url);
            let sorted = { users: [], karmas: [] };
            jsonResult.data.forEach(element => {
                //users are stored in the database encoded, atob() decodes them back into strings
                sorted.users.push(atob(element[0]));
                sorted.karmas.push(element[1]);
            });
            return sorted
        } catch (error) {
            console.error('ERROR HERE', error)
        }
    }

完整错误：

  Sorting
URL IS: http://undefined/getsorted/DESC
recievedKarmas::: Promise { <pending> }
    1) should return karma in DESC order
ERROR HERE { Error: getaddrinfo ENOTFOUND undefined undefined:80
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:56:26)
  errno: 'ENOTFOUND',
  code: 'ENOTFOUND',
  syscall: 'getaddrinfo',
  hostname: 'undefined',
  host: 'undefined',
  port: 80,
  config:
   { url: 'http://undefined/getsorted/DESC',
     method: 'get',
     headers:
      { Accept: 'application/json, text/plain, */*',
        'User-Agent': 'axios/0.19.0' },
     transformRequest: [ [Function: transformRequest] ],
     transformResponse: [ [Function: transformResponse] ],
     timeout: 0,
     adapter: [Function: httpAdapter],
     xsrfCookieName: 'XSRF-TOKEN',
     xsrfHeaderName: 'X-XSRF-TOKEN',
     maxContentLength: -1,
     validateStatus: [Function: validateStatus],
     data: undefined },
  request:
   Writable {
     _writableState:
      WritableState {
        objectMode: false,
        highWaterMark: 16384,
        finalCalled: false,
        needDrain: false,
        ending: false,
        ended: false,
        finished: false,
        destroyed: false,
        decodeStrings: true,
        defaultEncoding: 'utf8',
        length: 0,
        writing: false,
        corked: 0,
        sync: true,
        bufferProcessing: false,
        onwrite: [Function: bound onwrite],
        writecb: null,
        writelen: 0,
        bufferedRequest: null,
        lastBufferedRequest: null,
        pendingcb: 0,
        prefinished: false,
        errorEmitted: false,
        emitClose: true,
        bufferedRequestCount: 0,
        corkedRequestsFree: [Object] },
     writable: true,
     _events:
      [Object: null prototype] {
        response: [Function: handleResponse],
        error: [Function: handleRequestError] },
     _eventsCount: 2,
     _maxListeners: undefined,
     _options:
      { protocol: 'http:',
        maxRedirects: 21,
        maxBodyLength: 10485760,
        path: '/getsorted/DESC',
        method: 'GET',
        headers: [Object],
        agent: undefined,
        auth: undefined,
        hostname: 'undefined',
        port: 80,
        nativeProtocols: [Object],
        pathname: '/getsorted/DESC',
        proto: 'http',
        host: 'undefined:80' },
     _redirectCount: 0,
     _redirects: [],
     _requestBodyLength: 0,
     _requestBodyBuffers: [],
     _onNativeResponse: [Function],
     _currentRequest:
      ClientRequest {
        _events: [Object],
        _eventsCount: 6,
        _maxListeners: undefined,
        output: [],
        outputEncodings: [],
        outputCallbacks: [],
        outputSize: 0,
        writable: true,
        _last: true,
        chunkedEncoding: false,
        shouldKeepAlive: false,
        useChunkedEncodingByDefault: false,
        sendDate: false,
        _removedConnection: false,
        _removedContLen: false,
        _removedTE: false,
        _contentLength: 0,
        _hasBody: true,
        _trailer: '',
        finished: true,
        _headerSent: true,
        socket: [Socket],
        connection: [Socket],
        _header:
         'GET /getsorted/DESC HTTP/1.1rnAccept: application/json, text/plain, */*rnUser-Agent: axios/0.19.0rnHost: undefinedrnConnection: closernrn',
        _onPendingData: [Function: noopPendingOutput],
        agent: [Agent],
        socketPath: undefined,
        timeout: undefined,
        method: 'GET',
        path: '/getsorted/DESC',
        _ended: false,
        res: null,
        aborted: undefined,
        timeoutCb: null,
        upgradeOrConnect: false,
        parser: null,
        maxHeadersCount: null,
        _redirectable: [Circular],
        [Symbol(isCorked)]: false,
        [Symbol(outHeadersKey)]: [Object] },
     _currentUrl: 'http://undefined:80/getsorted/DESC' },
  response: undefined,
  isAxiosError: true,
  toJSON: [Function] }

  0 passing (24ms)
  1 failing
  1) Sorting
       should return karma in DESC order:
     AssertionError: expected {} to equal { Object (users, karmas) }
      at Context.<anonymous> (test/test-karma.js:21:16)

npm ERR! Test failed.  See above for more details.

因此，我知道测试至少要击中原始getSorted()功能，因为ERROR HERE已记录。但是我不明白为什么主机和主机名不确定。我明确说"服务器：4567"。

我认为我犯了一个愚蠢的错误，因为这只是我试图从基本单元测试中调用功能。

感谢您的帮助！

Answer 1

保持测试真正统一。您不应在单位测试中直接调用HTTP调用。这是因为您需要另一台服务器运行，因此它不再统一。

有避免这种情况的叛变方法。

1- proxyquire参考：https：//www.npmjs.com/package/proxyquire

需要您的文件进行测试，但用您自己替换一些依赖项。

不利的一面是，您不确定要替换哪个ProxyQuire。您将其委派到另一个图书馆。

const proxyquire =  require('proxyquire');
const assert = require('chai').assert;
const fakeStub = {} // This is some sort of fake or stub that prevent http call.
const getSorted = proxyquire('../src/karma', {axios: fakeStub }).getSorted; // Requires using your fake
describe('Sorting', function () {
    // If your test framework allow async function in test use it instead of done.  
    it('should return karma in DESC order', async function () {
        let expectedKarmas = { users: ['nikki', 'person', 'nolan'], karmas: ['3', '2', '1'] }
        let recievedKarmas = await getSorted("DESC"); // since it is async you have to wait otherwise it may be a promise
        assert.equal(recievedKarmas, expectedKarmas);
    });
});

2-添加覆盖钩

更多的控制权，并且可能具有某种特殊模式，可以避免使用Axios。

很难管理require的状态。再次需要时，模块轴可能仍被覆盖。

let axios = require("axios");
let atob = require('atob');
//end point is "server:4567"
let KARMABOT_API_ENDPOINT = process.env.KARMABOT_API_ENDPOINT;
module.exports = {
    overrideAxiosHook: (fakeAxios) => {
        axios = fakeAxios
    }
    // return the users sorted by amount of karma in directions of ASC (ascending) or DESC (descending)
    // object returned has a users array and a karmas array
    getSorted: async function (direction) {
        if (direction !== "ASC" && direction !== "DESC") {
            console.error("INVALID SORTING DIRECTION: %s. PLEASE PROVIDE ASC OR DESC", direction);
            return;
        }
        try {
            let url = `http://${KARMABOT_API_ENDPOINT}/getsorted/${direction}`;
            let jsonResult = await axios.get(url);
            let sorted = { users: [], karmas: [] };
            jsonResult.data.forEach(element => {
                //users are stored in the database encoded, atob() decodes them back into strings
                sorted.users.push(atob(element[0]));
                sorted.karmas.push(element[1]);
            });
            return sorted
        } catch (error) {
            console.error('ERROR HERE', error)
        }
    }
}

测试

const assert = require('chai').assert;
const {getSorted, overrideAxiosHook} = require('../src/karma');
const fakeStub = {} // This is some sort of fake or stub that prevent http call.
describe('Sorting', function () {
    before((done) => {
       overrideAxiosHook(fakeStub)
       done();
    });
    //If using done
    it('should return karma in DESC order', function (done) {
        let expectedKarmas = { users: ['nikki', 'person', 'nolan'], karmas: ['3', '2', '1'] }
        getSorted("DESC").then((recievedKarmas) => {
            assert.equal(recievedKarmas, expectedKarmas);
            done();
        });
    });
});

3-在模块中添加axois并使用this.axios

与＃2相同的缺点，但功能较少

let atob = require('atob');
//end point is "server:4567"
let KARMABOT_API_ENDPOINT = process.env.KARMABOT_API_ENDPOINT;
module.exports = {
    axios: require("axios")
    // return the users sorted by amount of karma in directions of ASC (ascending) or DESC (descending)
    // object returned has a users array and a karmas array
    getSorted: async function (direction) {
        if (direction !== "ASC" && direction !== "DESC") {
            console.error("INVALID SORTING DIRECTION: %s. PLEASE PROVIDE ASC OR DESC", direction);
            return;
        }
        try {
            let url = `http://${KARMABOT_API_ENDPOINT}/getsorted/${direction}`;
            let jsonResult = await this.axios.get(url);
            let sorted = { users: [], karmas: [] };
            jsonResult.data.forEach(element => {
                //users are stored in the database encoded, atob() decodes them back into strings
                sorted.users.push(atob(element[0]));
                sorted.karmas.push(element[1]);
            });
            return sorted
        } catch (error) {
            console.error('ERROR HERE', error)
        }
    }
}

4-使用真实的HTTP调用

下行需要另一台运行服务器。

process.env.KARMABOT_API_ENDPOINT = 'server:4567';
const assert = require('chai').assert;
const getSorted = require('../src/karma').getSorted;
describe('Sorting', function () {
    it('should return karma in DESC order', async function () {
        let expectedKarmas = { users: ['nikki', 'person', 'nolan'], karmas: ['3', '2', '1'] }
        let recievedKarmas = await getSorted("DESC");
        assert.equal(recievedKarmas, expectedKarmas);
    });
});