schema: remove error after lyd_value_validate_dflt calls

libyang returns the realtype field when the store callback return code
is LY_SUCCESS and LY_EINCOMPLETE.
Don't raise an error when lyd_value_validate_dflt returns
LY_EINCOMPLETE. The function can then use the val_type_cdata field.
Add a leafref with a default value to yolo-nodetypes.yang.
In this case, lyd_value_validate_dflt returns LY_EINCOMPLETE.
In test_schema.py, check that the default function returns a correct str
value.

Link: https://github.com/CESNET/libyang/blob/master/src/tree_data_common.c#L682
Signed-off-by: Jeremie Leska <[email protected]>

Author: jeremie6wind

libyang/schema.py

@@ -1545,7 +1545,7 @@ def default(self) -> Union[None, bool, int, str, float]:
                 val_type_cdata,
                 ffi.NULL,
             )
-            if ret != lib.LY_SUCCESS:
+            if ret not in (lib.LY_SUCCESS, lib.LY_EINCOMPLETE):
                 raise self.context.error("Unable to get real type of default value")
             self.cdata_default_realtype = Type(self.context, val_type_cdata[0], None)
 
@@ -1619,7 +1619,7 @@ def defaults(self) -> Iterator[Union[None, bool, int, str, float]]:
                     val_type_cdata,
                     ffi.NULL,
                 )
-                if ret != lib.LY_SUCCESS:
+                if ret not in (lib.LY_SUCCESS, lib.LY_EINCOMPLETE):
                     raise self.context.error("Unable to get real type of default value")
                 self.cdata_default_realtypes.append(
                     Type(self.context, val_type_cdata[0], None)

tests/test_schema.py

@@ -732,6 +732,9 @@ def test_must(self):
     def test_leaf_default(self):
         leaf = next(self.ctx.find_path("/yolo-nodetypes:conf/percentage"))
         self.assertIsInstance(leaf.default(), float)
+        leaf = next(self.ctx.find_path("/yolo-nodetypes:conf/leafref1"))
+        self.assertIsInstance(leaf.default(), str)
+        self.assertEqual("ASD", leaf.default())
 
     def test_leaf_parsed(self):
         leaf = next(self.ctx.find_path("/yolo-nodetypes:conf/percentage"))

tests/yang/yolo/yolo-nodetypes.yang

@@ -93,6 +93,13 @@ module yolo-nodetypes {
     leaf-list leaf-list2 {
       type string;
     }
+
+    leaf leafref1 {
+      type leafref {
+        path "/records/name";
+      }
+      default "ASD";
+    }
   }
 
   leaf test1 {