fix: post-validation sync in package model has always truthy fields

The logic of the sync was wrong, i.e. because the default-value string
fields were checked only for truthiness, the MSSDK model's values
wouldn't be propagated, and the default value would remain. While this
was OK for the tests, this causes a serious runtime problem for real
packages and notices, as the package would return the default ID
`no_id`.

Author: schivmeister

src/ted_sws/core/model/transform.py

@@ -311,12 +311,19 @@ def _populate_legacy_from_mssdk(self) -> None:
         """Populate legacy pipeline fields from MSSDK v2 fields when needed."""
         if self.metadata:
             # Populate basic legacy fields from metadata
-            self.identifier = self.identifier if self.identifier else self.metadata.identifier
-            self.title = self.title if self.title else self.metadata.title
-            self.created_at = self.created_at if self.created_at else self.metadata.issue_date
-            self.version = self.version if self.version else self.metadata.mapping_version
-            self.ontology_version = self.ontology_version if self.ontology_version else self.metadata.ontology_version
-            self.mapping_suite_hash_digest = self.mapping_suite_hash_digest if self.mapping_suite_hash_digest else self.metadata.signature
+            # Check against default values since they are truthy strings
+            if self.identifier == "no_id":
+                self.identifier = self.metadata.identifier
+            if self.title == "no_title":
+                self.title = self.metadata.title
+            if not self.created_at:
+                self.created_at = self.metadata.issue_date
+            if self.version == "0.1.1":
+                self.version = self.metadata.mapping_version
+            if self.ontology_version == "0.0.1":
+                self.ontology_version = self.metadata.ontology_version
+            if not self.mapping_suite_hash_digest:
+                self.mapping_suite_hash_digest = self.metadata.signature
             self.mapping_type = (
                 MappingPackageType.ELECTRONIC_FORMS
                 if self.metadata.type == "eforms"