Use simple tenants table check during hardening

For a niche opt-in feature, checking if the tenants table is in the current schema is good enough for determining if the current DB is central -- the solution where we added getCurrentDatabaseName to each manager was overly complicated for this (though a bit more correct, not worth the added complexity).

src/Bootstrappers/DatabaseTenancyBootstrapper.php

@@ -5,7 +5,7 @@ declare(strict_types=1);
 namespace Stancl\Tenancy\Bootstrappers;
 
 use Exception;
-use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
 use RuntimeException;
 use Stancl\Tenancy\Contracts\TenancyBootstrapper;
 use Stancl\Tenancy\Contracts\Tenant;
@@ -90,8 +90,7 @@ class DatabaseTenancyBootstrapper implements TenancyBootstrapper
     protected function verifyTenantCanUseDatabase(Tenant $tenant): void
     {
         /** @var \Stancl\Tenancy\Database\Models\Tenant&TenantWithDatabase $tenant */
-        $tenantDbConfig = $tenant->database();
-        $tenantDbName = $tenantDbConfig->getName();
+        $tenantDbName = $tenant->database()->getName();
 
         // Check that no other tenant uses this tenant's database
         if ($tenant::where($tenant->getTenantKeyName(), '!=', $tenant->getTenantKey())
@@ -100,14 +99,8 @@ class DatabaseTenancyBootstrapper implements TenancyBootstrapper
             throw new RuntimeException('Tenant cannot use a database of another tenant.');
         }
 
-        $manager = $tenantDbConfig->manager();
-
-        $centralConnection = DB::connection(config('tenancy.database.central_connection', 'central'));
-        $currentConnection = DB::connection();
-
-        // Throw if the current database/schema is central.
-        // At this point the connection should be the tenant's, so it should not match central.
-        if ($manager->getCurrentDatabaseName($currentConnection) === $manager->getCurrentDatabaseName($centralConnection)) {
+        if (Schema::hasTable($tenant->getTable())) {
+            // Throw if the current database/schema has the tenants table (i.e. it's not central)
             throw new RuntimeException('Tenant cannot use the central database.');
         }
     }

src/Database/Contracts/TenantDatabaseManager.php

@@ -4,8 +4,6 @@ declare(strict_types=1);
 
 namespace Stancl\Tenancy\Database\Contracts;
 
-use Illuminate\Database\Connection;
-
 interface TenantDatabaseManager
 {
     /** Create a database. */
@@ -19,12 +17,4 @@ interface TenantDatabaseManager
 
     /** Construct a DB connection config array. */
     public function makeConnectionConfig(array $baseConfig, string $databaseName): array;
-
-    /**
-     * Get the schema/database name that the given connection points to.
-     *
-     * In database managers, this should return the *database* name of the passed connection,
-     * while in schema managers, this should return the *schema* name of the passed connection.
-     */
-    public function getCurrentDatabaseName(Connection $connection): string;
 }

src/Database/TenantDatabaseManagers/PostgreSQLSchemaManager.php

@@ -4,7 +4,6 @@ declare(strict_types=1);
 
 namespace Stancl\Tenancy\Database\TenantDatabaseManagers;
 
-use Illuminate\Database\Connection;
 use Stancl\Tenancy\Database\Contracts\TenantWithDatabase;
 
 class PostgreSQLSchemaManager extends TenantDatabaseManager
@@ -38,10 +37,4 @@ class PostgreSQLSchemaManager extends TenantDatabaseManager
 
         return $baseConfig;
     }
-
-    public function getCurrentDatabaseName(Connection $connection): string
-    {
-        // Get the *schema* name (not the database name)
-        return $connection->selectOne('SELECT current_schema() AS schema')->schema;
-    }
 }

src/Database/TenantDatabaseManagers/SQLiteDatabaseManager.php

@@ -5,7 +5,6 @@ declare(strict_types=1);
 namespace Stancl\Tenancy\Database\TenantDatabaseManagers;
 
 use Closure;
-use Illuminate\Database\Connection;
 use Illuminate\Database\Eloquent\Model;
 use InvalidArgumentException;
 use PDO;
@@ -150,11 +149,6 @@ class SQLiteDatabaseManager implements TenantDatabaseManager
         return $baseConfig;
     }
 
-    public function getCurrentDatabaseName(Connection $connection): string
-    {
-        return $connection->getDatabaseName();
-    }
-
     public function getPath(string $name): string
     {
         $this->validateDatabaseName($name);

src/Database/TenantDatabaseManagers/TenantDatabaseManager.php

@@ -37,9 +37,4 @@ abstract class TenantDatabaseManager implements StatefulTenantDatabaseManager
 
         return $baseConfig;
     }
-
-    public function getCurrentDatabaseName(Connection $connection): string
-    {
-        return $connection->getDatabaseName();
-    }
 }