Fix: add validators to handle None values in Versions class (#1654)

* Fix: add validators to handle None values in Versions class

* Add unit test for migrating v0031 -> v0032

* Remove test temporarily

Author: georgesittas

sqlmesh/core/state_sync/base.py

@@ -43,6 +43,16 @@ class Versions(PydanticModel):
     def minor_sqlglot_version(self) -> t.Tuple[int, int]:
         return major_minor(self.sqlglot_version)
 
+    @field_validator("sqlglot_version", "sqlmesh_version", mode="before")
+    @classmethod
+    def _package_version_validator(cls, v: t.Any) -> str:
+        return "0.0.0" if v is None else str(v)
+
+    @field_validator("schema_version", mode="before")
+    @classmethod
+    def _schema_version_validator(cls, v: t.Any) -> int:
+        return 0 if v is None else int(v)
+
 
 MIGRATIONS = [
     importlib.import_module(f"sqlmesh.migrations.{migration}")

tests/core/test_state_sync.py

@@ -1062,6 +1062,14 @@ def test_get_version(state_sync: EngineAdapterStateSync) -> None:
         state_sync.get_versions()
     state_sync.get_versions(validate=False)
 
+    for empty_versions in (
+        Versions(),
+        Versions(schema_version=None, sqlglot_version=None, sqlmesh_version=None),
+    ):
+        assert empty_versions.schema_version == 0
+        assert empty_versions.sqlglot_version == "0.0.0"
+        assert empty_versions.sqlmesh_version == "0.0.0"
+
 
 def test_migrate(state_sync: EngineAdapterStateSync, mocker: MockerFixture) -> None:
     from sqlmesh import __version__ as SQLMESH_VERSION