Question

我有一个用于渲染Checkbox的React组件。组件代码有一个如下所示的函数：

const generateCheckboxes = (array, filterType) => {
        return array.map((filter, i) => {
            if (!isNullOrUndefined(filter) && filter !== "") {
                const applied = props.appliedFilterList[filterType].includes(filter);
                console.log("yes", props.appliedFilterList[filterType]);
                return (
                    <Row key={i} noLine={i === 0}>
                        <Checkbox checked={applied} onClick={() => props.toggleFilter(filterType, filter)}>
                            {filter}
                        </Checkbox>
                    </Row>
                );
            }
            return false;
        });
    };

渲染功能如下所示：

return (
        <div>
            <div>Access</div>
                {generateCheckboxes(props.accessFilters, "access")}

            <div>Bandwidth</div>
                {generateCheckboxes(props.bandwidthFilters, "bandwidth")}
        </div>   
    );

现在我正在尝试为这个组件编写一个测试，我只是将组件与Enzyme的浅层menthod中的props一起传递。我只想通过在测试用例中传递一些模拟数据来检查组件是否正确呈现。测试看起来像：

import React from "react";
import { mount, shallow } from "enzyme";
import Checkbox from "../../lib/Checkbox";
import FilterDropdownContent, { Header } from "../components/FilterDropdownContent";
import { generateCheckboxes } from "../components/FilterDropdownContent";
import { access } from "fs";

const accessData = ["Access Type Of The Service"];
const bandwidthData = ["the allowed band width", "the allowed band width"];
const termsFiltersData = ["term associated with the service"];
const appliedFilters = [
    {
        access: ["Access Type Of The Service"],
        bandwidth: ["the allowed band width", "the allowed band width"],
        term: ["term associated with the service"]
    }
];

describe("test the FilterDropdown component", () => {
    it("renders correctly", () => {
        const wrapper = mount(
            <FilterDropdownContent
                accessFilters={accessData}
                bandwidthFilters={bandwidthData}
                appliedFilterList={appliedFilters}
                termsFilters={termsFiltersData}
                toggleFilter={false}
            />
        );
    });
});

但我的测试因错误而失败： TypeError：无法读取属性'includes'of undefined

includes属性位于generateCheckboxes（）函数中。我已经在测试用例中传递了所需的道具。但我不确定是什么导致了这个问题。有人可以帮帮我吗？

Answer 1

在使用 Jest 时，使用 toEqual 而不是 toMatchObject 时也会发生错误 TypeError: Cannot read property 'includes' of undefined。

以下代码将给出 Cannot read property 'includes' of undefined 错误：

test("should return the correct data", async () => {
  const response = await fetch({ url: "http://localhost/" });

  expect(response).toEqual({
    body: new Blob(["raw data"]),
    status: 200,
    statusText: "OK",
  });
});

改用 toMatchObject 可以解决这个问题：

// ...
  expect(response).toMatchObject({
// ...

Answer 2

因为appliedFilters是一个数组：

const appliedFilters = [
    {
        access: ["Access Type Of The Service"],
        bandwidth: ["the allowed band width", "the allowed band width"],
        term: ["term associated with the service"]
    }
];

您的部分代码将解析为undefined：

props.appliedFilterList[filterType]

因为filterType === 'access'而不是数组索引。

尝试将appliedFilters更改为：

const appliedFilters = {
    access: ["Access Type Of The Service"],
    bandwidth: ["the allowed band width", "the allowed band width"],
    term: ["term associated with the service"]
};

在Jest和Enzyme中“无法读取属性包含未定义的”错误

2 个答案: