refactor test code for Counter component with @testing-library/dom

counter3.test.js

// Counter.test.js
import { getQueriesForElement } from "@testing-library/dom";
import ReactDOM, { unmountComponentAtNode } from "react-dom";
import { act } from "react-dom/test-utils";
import Counter from "./Counter";

let container = null;

export const render = (element) => {
  container = document.createElement("div");
  document.body.appendChild(container);
  act(() => {
    ReactDOM.render(element, container);
  });
  return getQueriesForElement(container);
};

export const cleanup = () => {
  unmountComponentAtNode(container);
  container.remove();
  container = null;
};

afterEach(() => {
  cleanup(container);
});

it("Counter 컴포넌트를 렌더링합니다", () => {
  const { getByText } = render(<Counter />);

  getByText("Counter: 0");
  getByText("+");
  getByText("-");
});