如何写一个笑话测试，将通过，如果返回值是对象的数组?

Question

我正在学习单元测试，我已经涵盖了相当多的基础知识。

现在我试着测试我的刮刀。我的初始功能涉及多个刮刀，但我想检查每个刮刀是否正常工作。测试的输出(为了测试成功)应该是如果返回有一个[{},{},...,{}]-对象数组。我真的不知道对象里面是什么(数据总是不同的)，但它总是一个对象数组。

现在我的问题是:如何正确地做到这一点?我试过很多方法，但我的测试总是失败。我已经关闭的是这个解决方案:

const santScraper = require('../scraping/scrapers/sant-scraper');
test('Does scraper works properly', async () => {
await expect(santScraper(1)).toBe({});
});

但是我的输出是这样的:

FAIL  tests/santScraper.test.js
× Does scraper works properly (20 ms)
● Does scraper works properly
expect(received).toBe(expected) // Object.is equality
- Expected  - 1
+ Received  + 1
- Object {}
+ Promise {}
2 |
3 | test('Does scraper works properly', async () => {
> 4 |   await expect(santScraper(1)).toBe({});
|                                ^
5 | });
6 |
at Object.<anonymous> (tests/santScraper.test.js:4:32)
Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 total
Snapshots:   0 total
Time:        2.016 s
Ran all test suites.
npm ERR! Test failed.  See above for more details.

我真的不知道它指的是什么

这是我的刮刀:

//const data_functions = require('../data-functions/data-functions');
const axios = require('axios'); //npm package - promise based http client
const cheerio = require('cheerio'); //npm package - used for web-scraping in server-side implementations
const data_functions = require('../data-functions/data-functions');
//santScaper function which as paramater needs count which is sent in the scraping-service file.
const santScraper = async (count) => {
const url = `https://www.sant.ba/pretraga/prodaja-1/tip-2/cijena_min-20000/stranica-${count}`;
const santScrapedData = [];
try {
await load_url(url, santScrapedData);
} catch (error) {
console.log(error);
}
};
//Function that does loading URL part of the scraper, and starting of process for fetching raw data.
const load_url = async (url, santScrapedData) => {
await axios.get(url).then((response) => {
const $ = cheerio.load(response.data);
get_article_html_nodes($).each((index, element) => {
process_single_article($, index, element, santScrapedData);
});
data_functions.mergeData(santScrapedData);
return santScrapedData; //this is where I return array of objects
});
};
// Part where raw html data is fetched but in div that we want.
const get_article_html_nodes = ($) => {
return $('div[class="col-xxs-12 col-xss-6 col-xs-6 col-sm-6 col-lg-4"]');
};
//Here is all logic for getting data that we want, from the raw html.
const process_single_article = ($, index, element, santScrapedData) => {
const getLink = $(element).find('a[class="re-image"]').attr('href');
const getDescription = $(element).find('a[class="title"]').text();
const getPrice = $(element)
.find('div[class="prices"] > h3[class="price"]')
.text()
.replace(/.| ?KM$/g, '')
.replace(',', '.');
const getPicture = $(element).find('img').attr('data-original');
const getSquaremeters = $(element)
.find('span[class="infoCount"]')
.first()
.text()
.replace(',', '.')
.split('m')[0];
const pricepersquaremeter =
parseFloat(getPrice) / parseFloat(getSquaremeters);
santScrapedData[index] = {
id: getLink.substring(42, 46),
link: getLink,
description: getDescription,
price: Math.round(getPrice),
picture: getPicture,
squaremeters: Math.round(getSquaremeters),
pricepersquaremeter: Math.round(pricepersquaremeter),
};
};
module.exports = santScraper;

Answer 1

在这种情况下，您可以像这样使用typeof:-

test('Does scraper works properly', async () => {
await expect(typeof santScraper(1)).toBe('object');
});

虽然它总是Promise对象，你想检查，你可以得到更具体的instanceof，像这样:-

test('Does scraper works properly', async () => {
await expect(santScraper(1) instanceof Promise).toBe(true);
});