Add PowerZone reference instance in chassis

Change-Id: I3fe84d3f2dbbbfc112a0d3d7e6739912ead75edf

rsd_lib/resources/v2_1/chassis/chassis.py

@@ -16,6 +16,7 @@
 from sushy.resources import base
 from sushy import utils
 
+from rsd_lib.resources.v2_1.chassis import power_zone
 from rsd_lib import utils as rsd_lib_utils
 
 
@@ -132,6 +133,22 @@ class Chassis(base.ResourceBase):
         """
         super(Chassis, self).__init__(connector, identity, redfish_version)
 
+    def _get_power_zone_collection_path(self):
+        """Helper function to find the PowerZoneCollection path"""
+        return utils.get_sub_resource_path_by(self, 'PowerZones')
+
+    @property
+    @utils.cache_it
+    def power_zones(self):
+        """Property to provide reference to `PowerZoneCollection` instance
+
+        It is calculated once when it is queried for the first time. On
+        refresh, this property is reset.
+        """
+        return power_zone.PowerZoneCollection(
+            self._conn, self._get_power_zone_collection_path(),
+            redfish_version=self.redfish_version)
+
     def update(self, asset_tag=None, location_id=None):
         """Update AssetTag and Location->Id properties
 

rsd_lib/tests/unit/resources/v2_1/chassis/test_chassis.py

@@ -11,12 +11,13 @@
 #    under the License.
 
 import json
-
 import mock
 
+from sushy import exceptions
 from sushy.tests.unit import base
 
 from rsd_lib.resources.v2_1.chassis import chassis
+from rsd_lib.resources.v2_1.chassis import power_zone
 
 
 class TestChassis(base.TestCase):
@@ -77,6 +78,63 @@ class TestChassis(base.TestCase):
         self.assertEqual('Unique ID', self.chassis_inst.oem.uuid)
         self.assertEqual('54.348103, 18.645172', self.chassis_inst.oem.geo_tag)
 
+    def test__get_power_zone_collection_path(self):
+        expected = '/redfish/v1/Chassis/Rack1/PowerZones'
+        result = self.chassis_inst._get_power_zone_collection_path()
+        self.assertEqual(expected, result)
+
+    def test__get_power_zone_collection_path_missing_processors_attr(self):
+        self.chassis_inst._json.pop('PowerZones')
+        self.assertRaisesRegex(
+            exceptions.MissingAttributeError, 'attribute PowerZones',
+            self.chassis_inst._get_power_zone_collection_path)
+
+    def test_power_zones(self):
+        # | GIVEN |
+        self.conn.get.return_value.json.reset_mock()
+        with open('rsd_lib/tests/unit/json_samples/v2_1/'
+                  'power_zone_collection.json', 'r') as f:
+            self.conn.get.return_value.json.return_value = json.loads(f.read())
+        # | WHEN |
+        actual_power_zones = self.chassis_inst.power_zones
+        # | THEN |
+        self.assertIsInstance(actual_power_zones,
+                              power_zone.PowerZoneCollection)
+        self.conn.get.return_value.json.assert_called_once_with()
+
+        # reset mock
+        self.conn.get.return_value.json.reset_mock()
+        # | WHEN & THEN |
+        # tests for same object on invoking subsequently
+        self.assertIs(actual_power_zones,
+                      self.chassis_inst.power_zones)
+        self.conn.get.return_value.json.assert_not_called()
+
+    def test_power_zones_on_refresh(self):
+        # | GIVEN |
+        with open('rsd_lib/tests/unit/json_samples/v2_1/'
+                  'power_zone_collection.json', 'r') as f:
+            self.conn.get.return_value.json.return_value = json.loads(f.read())
+        # | WHEN & THEN |
+        self.assertIsInstance(self.chassis_inst.power_zones,
+                              power_zone.PowerZoneCollection)
+
+        # On refreshing the chassis instance...
+        with open('rsd_lib/tests/unit/json_samples/v2_1/'
+                  'chassis.json', 'r') as f:
+            self.conn.get.return_value.json.return_value = json.loads(f.read())
+
+        self.chassis_inst.invalidate()
+        self.chassis_inst.refresh(force=False)
+
+        # | GIVEN |
+        with open('rsd_lib/tests/unit/json_samples/v2_1/'
+                  'power_zone_collection.json', 'r') as f:
+            self.conn.get.return_value.json.return_value = json.loads(f.read())
+        # | WHEN & THEN |
+        self.assertIsInstance(self.chassis_inst.power_zones,
+                              power_zone.PowerZoneCollection)
+
     def test_update(self):
         self.chassis_inst.update(asset_tag='Rack#1', location_id='1234')
         self.chassis_inst._conn.patch.assert_called_once_with(