Fix: Make sure that seed column hashes are updated during the migration (#863)

Author: izeigerman

sqlmesh/core/model/definition.py

@@ -790,7 +790,9 @@ def to_hydrated(self, content: str) -> SeedModel:
         """
         if self.is_hydrated:
             return self
-        return self.copy(update={"seed": Seed(content=content), "is_hydrated": True})
+        return self.copy(
+            update={"seed": Seed(content=content), "is_hydrated": True, "column_hashes_": None}
+        )
 
     def is_breaking_change(self, previous: Model) -> t.Optional[bool]:
         if not isinstance(previous, SeedModel):

sqlmesh/core/state_sync/engine_adapter.py

@@ -445,7 +445,7 @@ def _backup_state(self) -> None:
                     )
 
     def _migrate_rows(self) -> None:
-        all_snapshots = self._get_snapshots(lock_for_update=True)
+        all_snapshots = self._get_snapshots(lock_for_update=True, hydrate_seeds=True)
         environments = self.get_environments()
 
         snapshot_mapping = {}

tests/core/test_model.py

@@ -368,6 +368,7 @@ def test_seed_hydration():
     assert hydrated_model.is_hydrated
     assert hydrated_model.column_hashes == column_hashes
     assert hydrated_model.seed.content == model.seed.content
+    assert hydrated_model.column_hashes_ is None
 
 
 def test_seed():