add test for BelongsToMany relation with array foreign keys

tests/Models/Role.php

@@ -7,6 +7,7 @@
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use MongoDB\Laravel\Eloquent\DocumentModel;
+use MongoDB\Laravel\Relations\BelongsToMany;
 
 class Role extends Model
 {
@@ -22,6 +23,11 @@ public function user(): BelongsTo
         return $this->belongsTo(User::class);
     }
 
+    public function users(): BelongsToMany
+    {
+        return $this->belongsToMany(User::class, null, 'role_id', 'user_id');
+    }
+
     public function sqlUser(): BelongsTo
     {
         return $this->belongsTo(SqlUser::class);

tests/Models/User.php

@@ -17,6 +17,7 @@
 use MongoDB\Laravel\Eloquent\Builder;
 use MongoDB\Laravel\Eloquent\DocumentModel;
 use MongoDB\Laravel\Eloquent\MassPrunable;
+use MongoDB\Laravel\Relations\BelongsToMany;
 
 /**
  * @property string $id
@@ -87,6 +88,11 @@ public function role()
         return $this->hasOne(Role::class);
     }
 
+    public function roles(): BelongsToMany
+    {
+        return $this->belongsToMany(Role::class, null, 'user_id', 'role_id');
+    }
+
     public function sqlRole()
     {
         return $this->hasOne(SqlRole::class);

tests/RelationsTest.php

@@ -338,6 +338,22 @@ public function testBelongsToManyAttachArray(): void
         $this->assertCount(2, $user->clients);
     }
 
+    public function testBelongsToManyRelationSupportsArrayForeignKeys(): void
+    {
+        $user = User::create(['name' => 'John Doe']);
+        $role1 = Role::create(['name' => 'Admin']);
+        $role2 = Role::create(['name' => 'Editor']);
+
+        $user->roles()->attach([$role1->id, $role2->id]);
+
+        $retrievedUser = User::with('roles')->find($user->id);
+        $this->assertCount(2, $retrievedUser->roles);
+        $this->assertEqualsCanonicalizing(
+            [$role1->id, $role2->id],
+            $retrievedUser->roles->pluck('id')->toArray()
+        );
+    }
+
     public function testBelongsToManyAttachEloquentCollection(): void
     {
         User::create(['name' => 'John Doe']);