TypeError：無法讀取未定義（讀取“長度”）JEST 測試的屬性

Question

我正在嘗試對我的項目實施笑話測試，但在運行測試時出現錯誤。 問題是我在嘗試測試的代碼中並沒有真正的 length 方法。 它看起來像是出現在樣式組件中。 有什么辦法可以修復它，或者我可能解釋錯了？

測試

import React from "react";
import { render, screen } from "@testing-library/react";
import ChatBubblesContainer from "./ChatBubblesContainer";

let chats = [];

const mockUseContext = jest.fn().mockImplementation(() => ({
  chats: [],
}));

React.useContext = mockUseContext;

describe("test", () => {
  test("render", () => {
    render(<ChatBubblesContainer />);
    expect(screen.getByTestId("bubbles-container")).toBeInTheDocument();
  });
});

錯誤

TypeError: Cannot read properties of undefined (reading 'length')

      20 | describe("test", () => {
      21 |   test("render", () => {
    > 22 |     render(<ChatBubblesContainer />);
         |           ^
      23 |     expect(screen.getByTestId("bubbles-container")).toBeInTheDocument();
      24 |   });
      25 | });

      at charCodeAt (node_modules/styled-components/src/utils/hash.js:13:22)
      at e.hash [as generateAndInjectStyles] (node_modules/styled-components/src/models/ComponentStyle.js:80:53)
      at generateAndInjectStyles (node_modules/styled-components/src/models/StyledComponent.js:87:22)
      at node_modules/styled-components/src/models/StyledComponent.js:129:30
      at displayName (node_modules/styled-components/src/models/StyledComponent.js:247:14)
      at renderWithHooks (node_modules/react-dom/cjs/react-dom.development.js:16305:18)

Answer 1

當開玩笑無法從特定方法中識別出某些特定方法時會出現這種情況使用此代碼

jest.mock('PACKAGE NAME' , () => {
  MISSING VARIABLE OR FUNCTION IN ERROR DESCRIPTION : () =>  jest.fn();

})