schema: add {min,max}_elements for SList and SLeafList

This patch add ability to get minumum and maximum number of elements,
and add unit tests. The yolo-nodetypes module is used twice and is now
loaded in the list test setUp.

Fixes: #89
Signed-off-by: Stefan Gula <steweg@gmail.com>
Signed-off-by: Samuel Gauthier <samuel.gauthier@6wind.com>

Author: steweg

libyang/schema.py

@@ -1325,6 +1325,16 @@ def must_conditions(self) -> Iterator[str]:
         for must in ly_array_iter(pdata.musts):
             yield c2str(must.arg.str)
 
+    def max_elements(self) -> int:
+        return (
+            self.cdata_leaflist.max
+            if self.cdata_leaflist.max != (2**32 - 1)
+            else None
+        )
+
+    def min_elements(self) -> int:
+        return self.cdata_leaflist.min
+
     def __str__(self):
         return "%s %s" % (self.name(), self.type().name())
 
@@ -1423,6 +1433,12 @@ def uniques(self) -> Iterator[List[SNode]]:
                 nodes.append(SNode.new(self.context, node))
             yield nodes
 
+    def max_elements(self) -> int:
+        return self.cdata_list.max if self.cdata_list.max != (2**32 - 1) else None
+
+    def min_elements(self) -> int:
+        return self.cdata_list.min
+
     def __str__(self):
         return "%s [%s]" % (self.name(), ", ".join(k.name() for k in self.keys()))
 

tests/test_schema.py

@@ -291,6 +291,7 @@ class ListTest(unittest.TestCase):
     def setUp(self):
         self.ctx = Context(YANG_DIR)
         self.ctx.load_module("yolo-system")
+        self.ctx.load_module("yolo-nodetypes")
         self.list = next(self.ctx.find_path(self.PATH["LOG"]))
 
     def tearDown(self):
@@ -329,7 +330,6 @@ def test_list_parent(self):
         self.assertEqual(parent.name(), "conf")
 
     def test_list_uniques(self):
-        self.ctx.load_module("yolo-nodetypes")
         list1 = next(self.ctx.find_path("/yolo-nodetypes:conf/list1"))
         self.assertIsInstance(list1, SList)
         uniques = list(list1.uniques())
@@ -344,6 +344,17 @@ def test_list_uniques(self):
         uniques = list(list2.uniques())
         self.assertEqual(len(uniques), 0)
 
+    def test_list_min_max(self):
+        list1 = next(self.ctx.find_path("/yolo-nodetypes:conf/list1"))
+        self.assertIsInstance(list1, SList)
+        self.assertEqual(list1.min_elements(), 2)
+        self.assertEqual(list1.max_elements(), 10)
+
+        list2 = next(self.ctx.find_path("/yolo-nodetypes:conf/list2"))
+        self.assertIsInstance(list2, SList)
+        self.assertEqual(list2.min_elements(), 0)
+        self.assertEqual(list2.max_elements(), None)
+
 
 # -------------------------------------------------------------------------------------
 class RpcTest(unittest.TestCase):
@@ -531,3 +542,14 @@ def test_leaflist_defaults(self):
         leaflist = next(self.ctx.find_path("/yolo-nodetypes:conf/ratios"))
         for d in leaflist.defaults():
             self.assertIsInstance(d, float)
+
+    def test_leaf_list_min_max(self):
+        leaflist1 = next(self.ctx.find_path("/yolo-nodetypes:conf/leaf-list1"))
+        self.assertIsInstance(leaflist1, SLeafList)
+        self.assertEqual(leaflist1.min_elements(), 3)
+        self.assertEqual(leaflist1.max_elements(), 11)
+
+        leaflist2 = next(self.ctx.find_path("/yolo-nodetypes:conf/leaf-list2"))
+        self.assertIsInstance(leaflist2, SLeafList)
+        self.assertEqual(leaflist2.min_elements(), 0)
+        self.assertEqual(leaflist2.max_elements(), None)

tests/yang/yolo/yolo-nodetypes.yang

@@ -32,6 +32,8 @@ module yolo-nodetypes {
     list list1 {
       key leaf1;
       unique "leaf2 leaf3";
+      min-elements 2;
+      max-elements 10;
       leaf leaf1 {
         type string;
       }
@@ -49,5 +51,15 @@ module yolo-nodetypes {
         type string;
       }
     }
+
+    leaf-list leaf-list1 {
+      type string;
+      min-elements 3;
+      max-elements 11;
+    }
+
+    leaf-list leaf-list2 {
+      type string;
+    }
   }
 }