React Router ignores my PrivateRoute wrapper when navigating using a Link - reactjs

Question

I'm having a strange issue with React Router. My PrivateRoute wrapper doesn't do its thing when navigating using a Link or NavLink.
Essentially I have something like this:
<BrowserRouter>
<Switch>
<Route exact path="/"><Home /></Route>
<PrivateRoute exact path="/private"><Private /></PrivateRoute>
</Switch>
</BrowserRouter>
PrivateRoute is just a wrapper around Route that checks for authentication.
Now, if I go to /private by typing it in the address bar, PrivateRoute does its job (and redirects to /login, but that doesn't matter).
However, if I use a NavLink in the Home component which has to="/private", React Router routes to the private route even if the user is unauthenticated.
Is there any way I can resolve this reasonably? And why does React Router behave like this and doesn't "go through" all the routes in BrowserRouter each time you navigate using a NavLink?

Answer 1

To solve your problem, you need to add exact or exact="true" on public Route.
If you don't include exact="true", <Route path="/"> refers all sub routes starting with /.
So /private will match / route hence it will render <Home /> component.
Here is updated code
<BrowserRouter>
<Switch>
<Route path="/" exact>
<Home />
</Route>
<PrivateRoute path="/private">
<Private />
</PrivateRoute>
</Switch>
</BrowserRouter>
Here is sample code

Answer 2

Well, this was a quite simple and dumb fix actually.
The problem was that the PrivateRoute component didn't "remount" when changing routes using Links (that is interesting and somehow clever behavior of React Router, I can imagine this improves performance).
Meanwhile, typing a URL into the address bar refreshes the entire page, thus "remounting" all components.
Since the logic for checking auth was in componentDidMount only, it didn't launch if the component wasn't "remounted", therefore creating my issue.
For any possible future visitors, to fix this problem, just move your auth checking logic from componentDidMount somewhere else, and reference it both in componentDidMount and componentDidUpdate. Don't forget to check if props actually changed in componentDidUpdate — otherwise you'll create an infinite loop — like so:
componentDidUpdate(prevProps, prevState) {
// You could also use shallowCompare, but that wasn't needed in my case
if (this.props.requiredPerms !== prevProps.requiredPerms) {
this.checkAuth(); // method with the logic which was in componentDidMount before
}
}