reactjs - Jest 和 Enzyme 中的 "Cannot read property includes of undefined"错误

Question

我有一个用于呈现复选框的 React 组件。组件代码具有如下所示的功能:

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;
        });
    };

渲染函数如下所示:

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，我只是在 Enzyme 的浅层方法中传递组件和 Prop 。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}
            />
        );
    });
});

但我的测试失败并出现以下错误: TypeError:无法读取未定义的属性“includes”

includes 属性在 generateCheckboxes( ) 函数中。我已经在测试用例中传递了所需的 Prop 。但我不确定是什么导致了这个问题。有人可以帮我解决这个问题吗？

Answer 1

使用 Jest 时，错误 TypeError: Cannot read property 'includes' of undefined 也可能在使用 toEqual 而不是 toMatchObject 时发生。

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 将修复它:

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