Add LoginAttempting event for customizing authorization parameters

[evansims]

Changes

This PR implements a feature request by @elliottlawson to allow for easier customization of authorization parameters before a login redirect is issued.

This is implemented through a new event, Auth0\Laravel\Event\Stateful\LoginAttempting. Applications can hook into this event and use the setParameters() method of the event to define additional parameters to be issued with the login redirect.

Example usage:

<?php // app/Listeners/CustomLoginParameters.php

namespace App\Listeners;

use Auth0\Laravel\Event\Stateful\LoginAttempting;

final class CustomLoginParameters
{
    public function handle(LoginAttempting $event): void
    {
        $event->setParameters([
			'connection' => '...',
		]);
    }
}

<?php // app/Providers/EventServiceProvider.php

use Auth0\Laravel\Event\Stateful\LoginAttempting;
use App\Listeners\CustomLoginParameters;
use Illuminate\Support\Facades\Event;

public function boot(): void
{
    Event::listen(
        LoginAttempting::class,
        [CustomLoginParameters::class, 'handle']
    );
}

In the above example, the host application adds a custom event listener (app/Listeners/CustomLoginParameters.php) to listen for and respond to the new LoginAttempting event. In this case, a connection parameter is added to the request. The application's event service provider (app/Providers/EventServiceProvider.php) is also customized to register the new event listener, as required by Laravel.

References

Resolves #373

Testing

All tests passing.

Contributor Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 code of conduct

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (6f23b16) 100.00% compared to head (b929065) 100.00%.

Additional details and impacted files

@@             Coverage Diff             @@
##                main      #382   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity       295       295           
===========================================
  Files             21        21           
  Lines            806       806           
===========================================
  Hits             806       806           

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Http/Controller/Stateful/Login.php	100.00% <100.00%> (ø)

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[poovamraj]

LGTM 👍