sentry/tests/js/spec/utils/useRoutes.spec.tsx

import {createMemoryHistory, Route, Router, RouterContext} from 'react-router';

import {render} from 'sentry-test/reactTestingLibrary';

import {useRoutes} from 'sentry/utils/useRoutes';
import {RouteContext} from 'sentry/views/routeContext';

describe('useRoutes', () => {
  it('returns the current routes object', function () {
    let routes;
    function HomePage() {
      routes = useRoutes();
      return null;
    }

    const memoryHistory = createMemoryHistory();
    memoryHistory.push('/');

    render(
      <Router
        history={memoryHistory}
        render={props => {
          return (
            <RouteContext.Provider value={props}>
              <RouterContext {...props} />
            </RouteContext.Provider>
          );
        }}
      >
        <Route path="/" component={HomePage} />
      </Router>
    );
    expect(routes.length).toEqual(1);
    expect(routes[0]).toEqual({path: '/', component: HomePage});
  });

  it('throws error when called outside of routes provider', function () {
    try {
      const memoryHistory = createMemoryHistory();
      memoryHistory.push('/');

      render(
        <Router history={memoryHistory}>
          <Route
            path="/"
            component={() => {
              useRoutes();
              return null;
            }}
          />
        </Router>
      );
    } catch (error) {
      expect(error.message).toBe('useRouteContext called outside of routes provider');
    }
  });
});