schema: add parsed schema for union types

When available, let's add the parsed schema for union types, they will
be more complete, adding names, extensions, ranges, units, patterns,
etc.

Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>
Acked-by: Robin Jarry <robin@jarry.cc>

Author: samuel-gauthier

libyang/schema.py

@@ -479,9 +479,16 @@ def leafref_path(self) -> Optional["str"]:
     def union_types(self) -> Iterator["Type"]:
         if self.cdata.basetype != self.UNION:
             return
+
         t = ffi.cast("struct lysc_type_union *", self.cdata)
-        for union_type in ly_array_iter(t.types):
-            yield Type(self.context, union_type, None)
+        if self.cdata_parsed and self.cdata_parsed.types != ffi.NULL:
+            for union_type, union_type_parsed in zip(
+                ly_array_iter(t.types), ly_array_iter(self.cdata_parsed.types)
+            ):
+                yield Type(self.context, union_type, union_type_parsed)
+        else:
+            for union_type in ly_array_iter(t.types):
+                yield Type(self.context, union_type, None)
 
     def enums(self) -> Iterator[Enum]:
         if self.cdata.basetype != self.ENUM:

tests/test_schema.py

@@ -406,6 +406,12 @@ def test_leaf_type_union(self):
         self.assertEqual(t.base(), Type.UNION)
         types = set(u.name() for u in t.union_types())
         self.assertEqual(types, set(["int16", "int32", "uint16", "uint32"]))
+        for u in t.union_types():
+            ext = u.get_extension(
+                "type-desc", prefix="omg-extensions", arg_value=f"<{u.name()}>"
+            )
+            self.assertIsInstance(ext, Extension)
+            self.assertEqual(len(list(u.extensions())), 2)
         bases = set(t.basenames())
         self.assertEqual(bases, set(["int16", "int32", "uint16", "uint32"]))
 

tests/yang/wtf/wtf-types.yang

@@ -2,6 +2,8 @@ module wtf-types {
   namespace "urn:yang:wtf:types";
   prefix t;
 
+  import omg-extensions { prefix ext; }
+
   typedef str {
     type string;
   }
@@ -12,17 +14,32 @@ module wtf-types {
     }
   }
 
+  extension signed;
+  extension unsigned;
+
   typedef unsigned {
     type union {
-      type uint16;
-      type uint32;
+      type uint16 {
+        t:unsigned;
+        ext:type-desc "<uint16>";
+      }
+      type uint32 {
+        ext:type-desc "<uint32>";
+        t:unsigned;
+      }
     }
   }
 
   typedef signed {
     type union {
-      type int16;
-      type int32;
+      type int16 {
+        ext:type-desc "<int16>";
+        t:signed;
+      }
+      type int32 {
+        ext:type-desc "<int32>";
+        t:signed;
+      }
     }
   }