Add DatabaseTenancyBootstrapper::$harden

Since It's possible to update tenant's db_name to the central DB or the DB of another tenant. Setting $harden to true prevents tenants from connecting to the wrong databases.

src/Bootstrappers/DatabaseTenancyBootstrapper.php

@@ -5,14 +5,23 @@ declare(strict_types=1);
 namespace Stancl\Tenancy\Bootstrappers;
 
 use Exception;
+use Illuminate\Support\Facades\Schema;
+use RuntimeException;
 use Stancl\Tenancy\Contracts\TenancyBootstrapper;
 use Stancl\Tenancy\Contracts\Tenant;
 use Stancl\Tenancy\Database\Contracts\TenantWithDatabase;
 use Stancl\Tenancy\Database\DatabaseManager;
 use Stancl\Tenancy\Database\Exceptions\TenantDatabaseDoesNotExistException;
+use Illuminate\Database\Eloquent\Model;
 
 class DatabaseTenancyBootstrapper implements TenancyBootstrapper
 {
+    /**
+     * When true, throw an exception if a tenant gets connected to
+     * another tenant's database or to the central database.
+     */
+    public static bool $harden = false;
+
     /** @var DatabaseManager */
     protected $database;
 
@@ -41,10 +50,30 @@ class DatabaseTenancyBootstrapper implements TenancyBootstrapper
         }
 
         $this->database->connectToTenant($tenant);
+
+        if (static::$harden) $this->harden($tenant);
     }
 
     public function revert(): void
     {
         $this->database->reconnectToCentral();
     }
+
+    protected function harden(Tenant $tenant): void
+    {
+        /** @var TenantWithDatabase&Model $tenant */
+        $dbName = $tenant->database()->getName();
+
+        // Check if the current database is unique (i.e. no other tenant uses this database)
+        if ($tenant::where($tenant->getTenantKeyName(), '!=', $tenant->getTenantKey())
+            ->where('data->tenancy_db_name', $dbName)
+            ->exists()) {
+            throw new RuntimeException("Tenant cannot use a database of another tenant.");
+        }
+
+        // Check if the current database doesn't have the tenants table (i.e. it's not the central database)
+        if (Schema::hasTable($tenant->getTable())) {
+            throw new RuntimeException('Tenant cannot use the central database.');
+        }
+    }
 }

tests/Bootstrappers/DatabaseTenancyBootstrapper.php

@@ -1,18 +1,76 @@
 <?php
 
 use Illuminate\Support\Facades\Event;
+use Stancl\JobPipeline\JobPipeline;
 use Stancl\Tenancy\Bootstrappers\DatabaseTenancyBootstrapper;
 use Stancl\Tenancy\Events\TenancyEnded;
 use Stancl\Tenancy\Events\TenancyInitialized;
+use Stancl\Tenancy\Jobs\CreateDatabase;
+use Stancl\Tenancy\Events\TenantCreated;
 use Stancl\Tenancy\Listeners\BootstrapTenancy;
 use Stancl\Tenancy\Listeners\RevertToCentralContext;
 use Stancl\Tenancy\Tests\Etc\Tenant;
 
 use function Stancl\Tenancy\Tests\pest;
+use Illuminate\Support\Str;
 
-beforeEach(function () {
+$cleanup = function () {
+    DatabaseTenancyBootstrapper::$harden = false;
+};
+
+beforeEach(function () use ($cleanup) {
     Event::listen(TenancyInitialized::class, BootstrapTenancy::class);
     Event::listen(TenancyEnded::class, RevertToCentralContext::class);
+
+    $cleanup();
+});
+
+afterEach($cleanup);
+
+test('harden prevents tenants from using the central database', function () {
+    config([
+        'tenancy.bootstrappers' => [DatabaseTenancyBootstrapper::class],
+    ]);
+
+    DatabaseTenancyBootstrapper::$harden = true;
+
+    Event::listen(TenantCreated::class, JobPipeline::make([CreateDatabase::class])->send(function (TenantCreated $event) {
+        return $event->tenant;
+    })->toListener());
+
+    $tenant = Tenant::create();
+
+    $tenant->update([
+        'tenancy_db_name' => 'main', // Central database name
+    ]);
+
+    // Harden blocks initialization for tenants that use central database
+    expect(fn () => tenancy()->initialize($tenant))->toThrow(RuntimeException::class);
+});
+
+test('harden prevents tenants from using a database of another tenant', function () {
+    config([
+        'tenancy.bootstrappers' => [DatabaseTenancyBootstrapper::class],
+    ]);
+
+    DatabaseTenancyBootstrapper::$harden = true;
+
+    Event::listen(TenantCreated::class, JobPipeline::make([CreateDatabase::class])->send(function (TenantCreated $event) {
+        return $event->tenant;
+    })->toListener());
+
+    $tenant = Tenant::create();
+
+    Tenant::create([
+        'tenancy_db_name' => $tenantDbName = 'foo' . Str::random(8),
+    ]);
+
+    $tenant->update([
+        'tenancy_db_name' => $tenantDbName, // Database of another tenant
+    ]);
+
+    // Harden blocks initialization for tenants that use a database of another tenant
+    expect(fn () => tenancy()->initialize($tenant))->toThrow(RuntimeException::class);
 });
 
 test('database tenancy bootstrapper throws an exception if DATABASE_URL is set', function (string|null $databaseUrl) {
@@ -32,4 +90,3 @@ test('database tenancy bootstrapper throws an exception if DATABASE_URL is set',
 
     expect(true)->toBe(true);
 })->with(['abc.us-east-1.rds.amazonaws.com', null]);
-