如何使用 react-testing-library 模拟 window.location 变化

Question

我正在从 enzyme 迁移到 react-testing-library。我有一个名为 <ScrollToTop/> 的组件，它只检查自上次组件更新后 window.location 是否发生了变化，如果发生变化则滚动到顶部。

ScrollToTop.jsx

import React from "react";
import { withRouter } from "react-router-dom";

export class UnwrappedScrollToTop extends React.Component {
  componentDidUpdate(prevProps) {
    if (
      this.props.location !== prevProps.location &&
      !this.props.location.hash
    ) {
      window.scrollTo({ top: 0, behavior: "smooth" });
    }
  }

  render() {
    return this.props.children;
  }
}

export default withRouter(UnwrappedScrollToTop);

我的旧酶测试使用wrapper.setProps通过一个新的location然后测试是否调用window.scrollTo：

ScrollToTop.test.js

...
it("calls window.scrollTo (location changes, no hash)", () => {
    const wrapper = mount(
      <UnwrappedScrollToTop children="" location={{ pathname: "dashboard" }} />
    );


    // pass different location prop to trigger componentDidUpdate
    wrapper.setProps({ location: { pathname: "library" } });

    // check to see if scrollToMock was called in componentDidUpdate
    expect(ScrollToMock).toHaveBeenCalledWith({
      top: 0,
      behavior: "smooth"
    });
  });
...

但我不知道如何将其转换为 react-testing-library，因为我无法调用 setProps 来传递不同的位置。我将如何测试此组件？

Answer 1

最简单的方法是使用 render 返回的 rerender 函数。

const {rerender} = render(<UnwrappedScrollToTop children="" location={{ pathname: "dashboard" }} />)

rerender(<UnwrappedScrollToTop children="" location={{ pathname: "library" }} />)

expect(ScrollToMock).toHaveBeenCalledWith({
    top: 0,
    behavior: "smooth"
});

Link 到文档：https://testing-library.com/docs/react-testing-library/api/#rerender