From eec4f53e4282710e956670794b66b622aee73cec Mon Sep 17 00:00:00 2001
From: Stefan Gula <steweg@gmail.com>
Date: Tue, 28 Nov 2023 15:04:28 +0100
Subject: [PATCH] Adding only_node option to add_defaults

This patch allows user to use only_node option within add_defaults
function. This option limits the scope of creating and adding implicit
default data nodes to just given tree where DNode is considered as root
---
 cffi/cdefs.h                        |  1 +
 libyang/data.py                     | 11 ++++++++---
 tests/test_data.py                  | 21 ++++++++++++++++-----
 tests/yang/yolo/yolo-nodetypes.yang | 11 +++++++++++
 4 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/cffi/cdefs.h b/cffi/cdefs.h
index ba6bd5d4..bb5af6f1 100644
--- a/cffi/cdefs.h
+++ b/cffi/cdefs.h
@@ -1020,6 +1020,7 @@ LY_ERR lyd_merge_module(struct lyd_node **, const struct lyd_node *, const struc
 #define LYD_IMPLICIT_OUTPUT ...
 #define LYD_IMPLICIT_NO_DEFAULTS ...
 
+LY_ERR lyd_new_implicit_tree(struct lyd_node *, uint32_t, struct lyd_node **);
 LY_ERR lyd_new_implicit_all(struct lyd_node **, const struct ly_ctx *, uint32_t, struct lyd_node **);
 
 LY_ERR lyd_new_meta(const struct ly_ctx *, struct lyd_node *, const struct lys_module *, const char *, const char *, ly_bool, struct lyd_meta **);
diff --git a/libyang/data.py b/libyang/data.py
index c2bf95f5..60d03599 100644
--- a/libyang/data.py
+++ b/libyang/data.py
@@ -260,6 +260,7 @@ def add_defaults(
         no_defaults: bool = False,
         no_state: bool = False,
         output: bool = False,
+        only_node: bool = False,
     ):
         flags = implicit_flags(
             no_config=no_config,
@@ -267,9 +268,13 @@ def add_defaults(
             no_state=no_state,
             output=output,
         )
-        node_p = ffi.new("struct lyd_node **")
-        node_p[0] = self.cdata
-        ret = lib.lyd_new_implicit_all(node_p, self.context.cdata, flags, ffi.NULL)
+        if only_node:
+            node_p = ffi.cast("struct lyd_node *", self.cdata)
+            ret = lib.lyd_new_implicit_tree(node_p, flags, ffi.NULL)
+        else:
+            node_p = ffi.new("struct lyd_node **")
+            node_p[0] = self.cdata
+            ret = lib.lyd_new_implicit_all(node_p, self.context.cdata, flags, ffi.NULL)
         if ret != lib.LY_SUCCESS:
             raise self.context.error("cannot get module")
 
diff --git a/tests/test_data.py b/tests/test_data.py
index 25bec67d..ed9b8989 100644
--- a/tests/test_data.py
+++ b/tests/test_data.py
@@ -14,6 +14,7 @@
     DataType,
     DContainer,
     DLeaf,
+    DList,
     DNode,
     DNotif,
     DRpc,
@@ -32,6 +33,7 @@ def setUp(self):
         modules = [
             self.ctx.load_module("ietf-netconf"),
             self.ctx.load_module("yolo-system"),
+            self.ctx.load_module("yolo-nodetypes"),
         ]
 
         for mod in modules:
@@ -891,13 +893,22 @@ def test_find_all(self):
             dnode.free()
 
     def test_add_defaults(self):
-        dnode = self.ctx.parse_data_mem(self.JSON_CONFIG, "json", validate_present=True)
-        node = dnode.find_path("/yolo-system:conf/speed")
+        JSON = '{"yolo-nodetypes:records": [{"id": "rec1"}]}'
+        dnode = self.ctx.parse_data_mem(
+            JSON, "json", validate_present=True, parse_only=True
+        )
+        self.assertIsInstance(dnode, DList)
+        node = dnode.find_one("id")
         self.assertIsInstance(node, DLeaf)
-        node.free(with_siblings=False)
-        node = dnode.find_path("/yolo-system:conf/speed")
+        node = dnode.find_one("name")
+        self.assertIsNone(node)
+        dnode.add_defaults(only_node=True)
+        node = dnode.find_one("name")
+        self.assertIsInstance(node, DLeaf)
+        self.assertEqual(node.value(), "ASD")
+        node = dnode.find_path("/yolo-nodetypes:conf/speed")
         self.assertIsNone(node)
-        dnode.add_defaults()
+        dnode.add_defaults(only_node=False)
         node = dnode.find_path("/yolo-system:conf/speed")
         self.assertIsInstance(node, DLeaf)
         self.assertEqual(node.value(), 4321)
diff --git a/tests/yang/yolo/yolo-nodetypes.yang b/tests/yang/yolo/yolo-nodetypes.yang
index 3dd76832..6ff28f13 100644
--- a/tests/yang/yolo/yolo-nodetypes.yang
+++ b/tests/yang/yolo/yolo-nodetypes.yang
@@ -11,6 +11,17 @@ module yolo-nodetypes {
       "Initial version.";
   }
 
+  list records {
+    key id;
+    leaf id {
+      type string;
+    }
+    leaf name {
+      type string;
+      default "ASD";
+    }
+  }
+
   container conf {
     description
       "Configuration.";