Javascript 无法使用子组件测试React容器

我有一个react容器，默认情况下，我在其中加载无状态组件，没有任何条件，而测试时我无法通过测试

import React from 'react';
import { configure, shallow, mount } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';
import { AddProduct } from './AddProducts';
import card from '../../components/UI/card/card';
import { MemoryRouter } from 'react-router-dom';

configure({ adapter: new Adapter() });

describe('<AddProduct />', () => {
  let wrapper;

  beforeEach(() => {
    wrapper = shallow(
      <MemoryRouter>
        <AddProduct title="hi" />
      </MemoryRouter>,
    );
  });

  it('should render the card when its load', () => {
    expect(wrapper.find(card)).toHaveLength(1);
  });
});

从“React”导入React；
从“酶”导入{configure，shall，mount}；
从'enzyme-Adapter-react-16'导入适配器；
从“/AddProducts”导入{AddProduct}；
从“../../components/UI/card/card”导入卡片；
从'react router dom'导入{MemoryRouter}；
配置（{adapter:newadapter（）}）；
描述（“”，（）=>{
让包装纸；
在每个之前（（）=>{
包装纸=浅(
,
);
});
它（'加载时应呈现卡'，（）=>{
expect（wrapper.find（card））.toHaveLength（1）；
});
});

我期望卡组件的长度，但我收到0

 the Errors are like this.

● <AddProduct /> › should render the card when its load

    expect(received).toHaveLength(length)

    Expected value to have length:
      1
    Received:
 {"length": 0, Symbol(enzyme.__root__): {"length": 1, Symbol(enzyme.__root__): [Circular], Symbol(enzyme.__unrendered__): <MemoryRouter><AddProduct title="hi" /></MemoryRouter>, Symbol(enzyme.__renderer__): {"batchedUpdates": [Function batchedUpdates], "getNode": [Function getNode], "render": [Function render], "simulateEvent": [Function simulateEvent], "unmount": [Function unmount]},
Symbol(enzyme.__node__): {"instance": null, "key": undefined, "nodeType": "class", "props": {"children": <AddProduct title="hi" />, "history": {"action": "POP", "block": [Function block], "canGo": [Function canGo], "createHref": [Function createPath], "entries": [{"hash": "", "key": "3ozzvy", "pathname": "/", "search": "", "state": undefined}], "go": [Function go], "goBack": [Function goBack], "goForward": [Function goForward], "index": 0, "length": 1, "listen": [Function listen], "location": {"hash": "", "key": "3ozzvy", "pathname": "/", "search": "", "state": undefined}, "push": [Function push], "replace": [Function replace]}}, "ref": null, "rendered": {"instance": null, "key": undefined, "nodeType": "class", "props": {"title": "hi"}, "ref": null, "rendered": null, "type":
[Function AddProduct]}, "type": [Function Router]}, Symbol(enzyme.__nodes__): [{"instance": null, "key": undefined, "nodeType": "class", "props": {"children": <AddProduct title="hi" />, "history": {"action": "POP", "block": [Function block], "canGo": [Function canGo], "createHref": [Function createPath], "entries": [{"hash": "", "key": "3ozzvy", "pathname": "/", "search": "", "state": undefined}], "go": [Function go], "goBack": [Function goBack], "goForward": [Function goForward], "index": 0, "length": 1, "listen": [Function listen], "location": {"hash": "", "key": "3ozzvy", "pathname": "/", "search": "", "state": undefined}, "push": [Function push], "replace": [Function replace]}}, "ref": null, "rendered": {"instance": null, "key": undefined, "nodeType": "class", "props": {"title": "hi"}, "ref": null, "rendered": null, "type": [Function AddProduct]}, "type": [Function Router]}], Symbol(enzyme.__options__): {"adapter": {"options": {"enableComponentDidUpdateOnSetState": true}}}}, Symbol(enzyme.__unrendered__): null, Symbol(enzyme.__renderer__): {"batchedUpdates": [Function batchedUpdates], "getNode": [Function getNode], "render": [Function render], "simulateEvent": [Function simulateEvent], "unmount": [Function unmount]}, Symbol(enzyme.__node__): undefined, Symbol(enzyme.__nodes__): Array [], Symbol(enzyme.__options__): {"adapter": {"options": {"enableComponentDidUpdateOnSetState": true}}}}
    received.length:
      0

      at Object.it (src/containers/Products/AddProducts.test.js:18:46)
          at new Promise (<anonymous>)
      at Promise.resolve.then.el (node_modules/p-map/index.js:46:16)
          at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:188:7)

错误如下所示。
●  › 应在加载卡时呈现该卡
expect（已接收）。toHaveLength（长度）
期望值具有以下长度：
1.
收到：
{“长度”：0，符号（酶.uuuu根）：{“长度”：1，符号（酶.uuuu根）：[Circular]，符号（酶.uuuuu未渲染）：符号（酶.uuuuu渲染器）:{“BatchedUpdate:[Function BatchedUpdate]，“getNode:[Function getNode]，“render:[Function render]，“simulateEvent:[Function simulateEvent]，“unmount:[Function unmount]，
符号（酶.uuu节点.uuuuu）：{“实例”：null，“键”：未定义，“节点类型”：“类”，“道具”：{“子项”：“历史”：{“操作”：“弹出”，“块”：[函数块]，“canGo”：[Function canGo]，“createHref”：[Function createPath]，“条目”：[{“哈希”：“键”：“3ozvy”，“路径名”：“/，“搜索”：“状态”：未定义的}]，“go，“goBack”：[函数goBack]，“goForward”：[函数goForward]，“index”：0，“length”：1，“listen”：[函数listen]，“location”：{“hash”：“key”：“3ozvy”，“pathname”：“/”，“search”：“state”：未定义的}，“push”：[函数push]，“replace”：[函数替换]}，“ref”：null，“rendered”：{“instance”：null，“key”：未定义的，“nodeype”：”类“，”props“：{“title”：“hi”}，“ref”：null，“rendered”：null，“type”：
[Function AddProduct]}，“type”：[Function Router]}，Symbol（酵素）.\uuuuu节点\uuuuuuu）：[{“实例”：null，“键”：未定义，“节点类型”：“类”，“道具”：“{”子项”：“历史”：“{”动作”：“POP”，“块”：[Function block]，“canGo”：[Function canGo]，“createHref”：[Function createPath]，“条目”：[{“哈希”：“，“键”：“3OZVY”，“路径名”：“/“搜索”“：”，“state”：未定义的}]，“go”：[Function go]，“goBack”：[Function goBack]，“goForward”：[Function goForward]，“index”：0，“length”：1，“listen”：[Function listen]，“location”：{“hash”：“key”：“3ozvy”，“pathname”：“/，“search”：“state”：未定义的}，“push”：[Function push]，“replace”：[Function replace]}，“ref”：null，“rendered”：{“实例”：null，“键”：未定义，“节点类型”：“类”，“道具”：{“标题”：“hi”}，“ref”：null，“呈现”：null，“类型”：[Function AddProduct]}，“类型”：[Function Router]}]，Symbol（酵素）{“适配器”：{“选项”：{“选项”：{“enableComponentDidUpdateOnSetState”：true}}}}，Symbol（酵素）{BatchedUpdate:[Function BatchedUpdate]，“getNode:[Function getNode]，“render:[Function render]，“simulateEvent:[Function simulateEvent]，“unmount:[Function unmount]}，Symbol（enzyme.\uuuuuuuu nodes）:[Function getNode]，“render:[Function simulateEvent]，“unmount:[Function unmount]，[Function unmount]，[Function unmount]，[Function.\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu
收到。长度：
0
在Object.it（src/containers/Products/AddProducts.test.js:18:46）
在新的承诺（）
在Promise.resolve.then.el（node_modules/p-map/index.js:46:16）
在
在进程中。_tick回调（内部/process/next_tick.js:188:7）

哪个组件正在使用

卡

组件？卡是=>内部的无状态组件呈现，而AddProduct是容器。为什么没有

，您不休息一下
？