fixup! ✨(backend) add shortcut item type targeting another item

src/backend/core/migrations/0028_item_add_shortcut_target.py

@@ -14,7 +14,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='item',
             name='target',
-            field=models.OneToOneField(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='shortcut', to='core.item'),
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='shortcuts', to='core.item'),
         ),
         migrations.AlterField(
             model_name='item',
@@ -25,4 +25,8 @@ class Migration(migrations.Migration):
             model_name='item',
             constraint=models.CheckConstraint(condition=models.Q(models.Q(('type', 'shortcut'), ('target__isnull', False)), models.Q(models.Q(('type', 'shortcut'), _negated=True), ('target__isnull', True)), _connector='OR'), name='check_target_only_on_shortcuts'),
         ),
+        migrations.AddConstraint(
+            model_name='item',
+            constraint=models.UniqueConstraint(fields=('target',), name='unique_shortcut_per_target'),
+        ),
     ]

src/backend/core/models.py

@@ -1021,10 +1021,10 @@ class Item(TreeModel, BaseModel):
     )
     mimetype = models.CharField(max_length=255, null=True, blank=True)
     is_restricted = models.BooleanField(default=False)
-    target = models.OneToOneField(
+    target = models.ForeignKey(
         "self",
         on_delete=models.CASCADE,
-        related_name="shortcut",
+        related_name="shortcuts",
         null=True,
         blank=True,
     )
@@ -1070,6 +1070,10 @@ class Item(TreeModel, BaseModel):
                 ),
                 name="check_target_only_on_shortcuts",
             ),
+            models.UniqueConstraint(
+                fields=["target"],
+                name="unique_shortcut_per_target",
+            ),
         ]
         indexes = [
             GistIndex(fields=["path"]),
@@ -1247,6 +1251,11 @@ class Item(TreeModel, BaseModel):
             return self._meta.model.objects.filter(path=str(self.path[:-1])).first()
         return None
 
+    @property
+    def shortcut(self):
+        """Return the shortcut targeting this item, if any."""
+        return self._meta.model.objects.filter(target=self).first()
+
     def invalidate_nb_accesses_cache(self):
         """
         Invalidate the cache for number of accesses, including on affected descendants.