If the project using configuration file has unsynced locales, perform forced sync (#3615)

Co-authored-by: Eemeli Aro <eemeli@gmail.com>

Author: mathjazz

pontoon/base/models/project.py

@@ -7,6 +7,7 @@
 from django.db.models import Sum
 from django.db.models.manager import BaseManager
 from django.utils import timezone
+from django.utils.functional import cached_property
 
 from pontoon.base.aggregated_stats import AggregatedStats
 from pontoon.base.models.locale import Locale
@@ -231,6 +232,17 @@ class Meta:
     def __str__(self):
         return self.name
 
+    @cached_property
+    def unsynced_locales(self):
+        """
+        Project Locales that haven't been synchronized yet.
+        """
+        return self.locales.exclude(
+            pk__in=Locale.objects.filter(
+                translatedresources__resource__project=self
+            ).values_list("pk", flat=True)
+        )
+
     def serialize(self):
         return {
             "pk": self.pk,

pontoon/sync/core/checkout.py

@@ -99,6 +99,11 @@ def checkout_repos(
     """
     source: Checkout | None = None
     target: Checkout | None = None
+
+    # If the project using configuration file has unsynced locales, perform forced sync
+    if not force and project.configuration_file and project.unsynced_locales:
+        force = True
+
     for repo in cast(BaseManager[Repository], project.repositories).all():
         if repo.source_repo:
             if source: