Add info about default values to describe

Change-Id: I9919e0d366b56ac17e7b606aa5aa0ae048b447c3
diff --git a/tests/yang.cpp b/tests/yang.cpp
index a458909..598f115 100644
--- a/tests/yang.cpp
+++ b/tests/yang.cpp
@@ -130,6 +130,7 @@
 
     leaf leafUint64 {
         type uint64;
+        default 9001;
     }
 
     leaf leafEnum {
@@ -146,6 +147,7 @@
             enum data;
             enum coze;
         }
+        default data;
     }
 
     typedef enumTypedefRestricted {
@@ -939,6 +941,13 @@
             REQUIRE_FALSE(ys.isConfig("/example-schema:systemStats/upTime"));
         }
 
+        SECTION("defaultValue")
+        {
+            REQUIRE(ys.defaultValue("/example-schema:leafUint64") == "9001");
+            REQUIRE(ys.defaultValue("/example-schema:leafEnumTypedefRestricted") == "data");
+            REQUIRE(ys.defaultValue("/example-schema:leafInt32") == std::nullopt);
+        }
+
         SECTION("moduleNodes")
         {
             std::string module;