feature #22048 [Security] deprecate the Role and SwitchUserRole classes (xabbuh)

This PR was merged into the 4.3-dev branch.

Discussion
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[Security] deprecate the Role and SwitchUserRole classes

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #20824
| License       | MIT
| Doc PR        | symfony/symfony-docs#11047

In #20801, we deprecated the `RoleInterface`. The next logical step would be to also deprecate the `Role` class. However, we currently have the `SwitchUserRole` class (a sub-class of `Role`) that acts as an indicator to check whether or not the authenticated user switched to another user.

This PR proposes an alternative solution to the usage of the special `SwitchUserRole` class by storing the original token inside the `UsernamePasswordToken`. This PR is not complete, but rather acts as a proof of concept of how we could get rid of the `Role` and the `SwitchUserRole` classes.

Please share your opinions whether you think this is a valid approach and I will be happy to finalise the PR.

Commits
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d7aaa615b9 deprecate the Role and SwitchUserRole classes

Author: fabpot

Processor/TokenProcessor.php

@@ -31,10 +31,16 @@ public function __invoke(array $records)
     {
         $records['extra']['token'] = null;
         if (null !== $token = $this->tokenStorage->getToken()) {
+            if (method_exists($token, 'getRoleNames')) {
+                $roles = $token->getRoleNames();
+            } else {
+                $roles = array_map(function ($role) { return $role->getRole(); }, $token->getRoles(false));
+            }
+
             $records['extra']['token'] = [
                 'username' => $token->getUsername(),
                 'authenticated' => $token->isAuthenticated(),
-                'roles' => array_map(function ($role) { return $role->getRole(); }, $token->getRoles()),
+                'roles' => $roles,
             ];
         }
 

Tests/Processor/TokenProcessorTest.php

@@ -36,7 +36,6 @@ public function testProcessor()
         $this->assertArrayHasKey('token', $record['extra']);
         $this->assertEquals($token->getUsername(), $record['extra']['token']['username']);
         $this->assertEquals($token->isAuthenticated(), $record['extra']['token']['authenticated']);
-        $roles = array_map(function ($role) { return $role->getRole(); }, $token->getRoles());
-        $this->assertEquals($roles, $record['extra']['token']['roles']);
+        $this->assertEquals(['ROLE_USER'], $record['extra']['token']['roles']);
     }
 }