React快速调试的小技巧：直接在组件上输出props/state

const App = () => (
  <BrowserRouter>
    <div className="app">
      <Switch>
        <Route exact path="/" component={Landing} />
        <Route path="/search" component={Search} />
        <Route path="/details/:id" component={Details} />
        <Route component={FourOhFour} />
      </Switch>
    </div>
  </BrowserRouter>
);

const Details = props => (
  <div className="details">
    <pre>
      <code>
        {JSON.stringify(props, null, 4)}
      </code>
    </pre>
  </div>
);