Feature Request: [authentication-client] event on auth failure

[KrishnaPG]

In the authentication-client, when auth attempt is made, login and authenticated events are generated for the auth success case:

feathers/packages/authentication-client/src/core.ts

Lines 165 to 167 in 9fe55b3

	this.authenticated = true;
	this.app.emit('login', authResult);
	this.app.emit('authenticated', authResult);

However, there is no event for auth failure case. Only the promise is rejected.

This feature-request is: please raise an event (something like authFailure event) in the failure case, in the catch handler shown below:

feathers/packages/authentication-client/src/core.ts

Lines 170 to 172 in 9fe55b3

	}).catch((error: FeathersError) =>
	this.handleError(error, 'authenticate')
	);

Such event makes it possible to watch for the login and authFailure events from anywhere in the app across different services and enable/disable certain functionality. Currently, we are handling success in the event, and failure in the catch handler, not so elegant.

fClient.on('login', authResult => Store.setUser(authResult));
fClient.on('logout', () => Store.clearUser());
fClient.on('authFailure', () => Store.clearUser()); //<-- this is not available currently

[daffl]

This is already possible with a short client side error hook:

fClient.service('authentication').hooks({
  error (context) {
    fClient.emit('authFailure', context.error);
  }
});

[KrishnaPG]

Thank you @daffl

When using .authenticate() the hook seems to be getting invoked fine. But when doing .reAuthenticate(true) the hook is not getting invoked for some reason.

For example,

    fClient.reAuthenticate(true).catch(ex => {
      console.log("caught exception: ", ex);
    });

fClient.service('authentication').hooks({
	error(context) {
		console.log("auth error ", context.error);
	}
});

the catch exception handlers gets invoked, but not the hook for reAuth failure when validating an already stored JWT.

That is the main scenario I am trying to handle.

When socket reconnections happen the login event is generated for successful reAuth (see below handleSocket code). But when the stored JWT is failed to reAuth on reconnect, we would not know

feathers/packages/authentication-client/src/core.ts

Lines 70 to 74 in 9fe55b3

	// Only reconnect when `reAuthenticate()` or `authenticate()`
	// has been called explicitly first
	// Force reauthentication with the server
	.then(() => this.authenticated ? this.reAuthenticate(true) : null);

[daffl]

Ah, indeed, the correct code is

fClient.hooks({
  error (context) {
    const { error } = context;

    if (error.code === 401) {
      client.emit('authFailure', error);
    }

    return context;
  }
});

This should emit the event on any authentication failure.