MAINT: Add defaults to DerivedNamedStratigraphy

Also fixed an annotation error.

src/fmu/dataio/providers/objectdata/_base.py

@@ -47,14 +47,14 @@ class DerivedObjectDescriptor:
 @dataclass
 class DerivedNamedStratigraphy:
     name: str
-    alias: list[str]
+    alias: list[str] = field(default_factory=list)
 
-    stratigraphic: bool
-    stratigraphic_alias: list[str]
+    stratigraphic: bool = field(default=False)
+    stratigraphic_alias: list[str] = field(default_factory=list)
 
-    offset: int
-    base: str | None
-    top: str | None
+    offset: float = field(default=0.0)
+    base: str | None = field(default=None)
+    top: str | None = field(default=None)
 
 
 def derive_name(
@@ -266,25 +266,19 @@ def _derive_name_stratigraphy(self) -> DerivedNamedStratigraphy:
         strat = self.dataio.config.get("stratigraphy", {})
         no_stratigraphy_or_name = strat is None or name not in strat
 
+        if no_stratigraphy_or_name:
+            return DerivedNamedStratigraphy(name=name)
+
         rv = DerivedNamedStratigraphy(
-            name=name if no_stratigraphy_or_name else strat[name].get("name", name),
-            alias=[] if no_stratigraphy_or_name else strat[name].get("alias", []),
-            stratigraphic=(
-                False
-                if no_stratigraphy_or_name
-                else strat[name].get("stratigraphic", False)
-            ),
-            stratigraphic_alias=(
-                []
-                if no_stratigraphy_or_name
-                else strat[name].get("stratigraphic_alias")
-            ),
-            offset=0.0 if no_stratigraphy_or_name else strat[name].get("offset", 0.0),
-            top=None if no_stratigraphy_or_name else strat[name].get("top"),
-            base=None if no_stratigraphy_or_name else strat[name].get("base"),
+            name=strat[name].get("name", name),
+            alias=strat[name].get("alias", []),
+            stratigraphic=strat[name].get("stratigraphic", False),
+            stratigraphic_alias=strat[name].get("stratigraphic_alias"),
+            offset=strat[name].get("offset", 0.0),
+            top=strat[name].get("top"),
+            base=strat[name].get("base"),
         )
-
-        if not no_stratigraphy_or_name and rv.name != "name":
+        if rv.name != "name":
             rv.alias.append(name)
 
         return rv