Pending tenants refactor (BC break)

- [BC BREAK] Make pullPendingFromPool() $firstOrCreate arg
  default to false (pullPending() is now a direct alias for
  pullPendingFromPool() with default $firstOrCreate=true)
- Resolve race conditions in pullPendingFromPool()
- Make createPending() set pending_since regardless of exceptions
- Make pullPending() accept $attributes
- Fire PullingPendingTenant from within a DB transaction
- Clarify --count arg description for CreatePendingTenants command
- Add docblock to PullingPendingTenant with a notice

src/Commands/CreatePendingTenants.php

@@ -8,7 +8,7 @@ use Illuminate\Console\Command;
 
 class CreatePendingTenants extends Command
 {
-    protected $signature = 'tenants:pending-create {--count= : The number of pending tenants to be created}';
+    protected $signature = 'tenants:pending-create {--count= : The number of pending tenants to maintain}';
 
     protected $description = 'Create pending tenants.';
 

src/Database/Concerns/HasPending.php

@@ -6,14 +6,13 @@ namespace Stancl\Tenancy\Database\Concerns;
 
 use Carbon\Carbon;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Support\Facades\DB;
 use Stancl\Tenancy\Contracts\Tenant;
 use Stancl\Tenancy\Events\CreatingPendingTenant;
 use Stancl\Tenancy\Events\PendingTenantCreated;
 use Stancl\Tenancy\Events\PendingTenantPulled;
 use Stancl\Tenancy\Events\PullingPendingTenant;
 
-// todo consider adding a method that sets pending_since to null — to flag tenants as not-pending
-
 /**
  * @property ?Carbon $pending_since
  *
@@ -50,46 +49,62 @@ trait HasPending
      */
     public static function createPending(array $attributes = []): Model&Tenant
     {
+        try {
             $tenant = static::create($attributes);
-
             event(new CreatingPendingTenant($tenant));
-
+        } finally {
             // Update the pending_since value only after the tenant is created so it's
-        // Not marked as pending until finishing running the migrations, seeders, etc.
+            // not marked as pending until after migrations, seeders, etc are run.
             $tenant->update([
                 'pending_since' => now()->timestamp,
             ]);
+        }
 
         event(new PendingTenantCreated($tenant));
 
         return $tenant;
     }
 
-    /** Pull a pending tenant. */
+    /**
-    public static function pullPending(): Model&Tenant
+     * Pull a pending tenant from the pool or create a new one if the pool is empty.
+     *
+     * @param array $attributes The attributes to set on the tenant.
+     */
+    public static function pullPending(array $attributes = []): Model&Tenant
     {
         /** @var Model&Tenant $pendingTenant */
-        $pendingTenant = static::pullPendingFromPool(true);
+        $pendingTenant = static::pullPendingFromPool(true, $attributes);
 
         return $pendingTenant;
     }
 
-    /** Try to pull a tenant from the pool of pending tenants. */
+    /**
-    public static function pullPendingFromPool(bool $firstOrCreate = true, array $attributes = []): ?Tenant
+     * Try to pull a tenant from the pool of pending tenants.
+     *
+     * @param bool $firstOrCreate If true, a tenant will be *created* if the pool is empty. Otherwise null is returned.
+     * @param array $attributes The attributes to set on the tenant.
+     */
+    public static function pullPendingFromPool(bool $firstOrCreate = false, array $attributes = []): ?Tenant
     {
+        $tenant = DB::transaction(function () use ($attributes): ?Tenant {
             /** @var (Model&Tenant)|null $tenant */
             $tenant = static::onlyPending()->first();
 
+            if ($tenant !== null) {
+                event(new PullingPendingTenant($tenant));
+                $tenant->update(array_merge($attributes, [
+                    'pending_since' => null,
+                ]));
+            }
+
+            return $tenant;
+        });
+
         if ($tenant === null) {
             return $firstOrCreate ? static::create($attributes) : null;
         }
 
-        event(new PullingPendingTenant($tenant));
+        // Only triggered if a tenant that was pulled from the pool is returned
-
-        $tenant->update(array_merge($attributes, [
-            'pending_since' => null,
-        ]));
-
         event(new PendingTenantPulled($tenant));
 
         return $tenant;

src/Events/PullingPendingTenant.php

@@ -4,4 +4,9 @@ declare(strict_types=1);
 
 namespace Stancl\Tenancy\Events;
 
+/**
+ * Importantly, listeners for this event should not switch tenancy context.
+ *
+ * This event is fired from within a database transaction.
+ */
 class PullingPendingTenant extends Contracts\TenantEvent {}