add BaseMetadata compare test coverage

lib/iris/common/lenient.py

@@ -407,7 +407,7 @@ def enable(self, state):
             raise ValueError(emsg)
         self.__dict__["enable"] = state
 
-    def register_client(self, func, services):
+    def register_client(self, func, services, append=False):
         """
         Add the provided mapping of lenient client function/method to
         required lenient service function/methods.
@@ -422,6 +422,12 @@ def register_client(self, func, services):
             One or more service function/methods or fully qualified string names
             of the required service function/method.
 
+        Kwargs:
+
+        * append (bool):
+            If True, append the lenient services to any pre-registered lenient
+            services for the provided lenient client. Default is False.
+
         """
         func = qualname(func)
         cls = self.__class__.__name__
@@ -437,6 +443,11 @@ def register_client(self, func, services):
             emsg = f"Require at least one {cls!r} lenient client service."
             raise ValueError(emsg)
         services = tuple([qualname(service) for service in services])
+        if append:
+            # Service order is not significant, therefore there is no
+            # requirement to preserve it.
+            existing = self.__dict__[func] if func in self else ()
+            services = tuple(sorted(set(existing) | set(services)))
         self.__dict__[func] = services
 
     def register_service(self, func):

lib/iris/common/metadata.py

@@ -156,14 +156,14 @@ def func(field):
                 value = getattr(self, field)
                 return value if value == getattr(other, field) else None
 
-            # Note that, we use "_fields" not "_members".
+            # Note that, for strict we use "_fields" not "_members".
             values = [func(field) for field in self._fields]
 
         return values
 
     def _combine_lenient(self, other):
         """
-        Perform lenient metadata member combination.
+        Perform lenient combination of metadata members.
 
         Args:
 
@@ -221,7 +221,7 @@ def _combine_lenient_attributes(left, right):
 
     def _compare_lenient(self, other):
         """
-        Support lenient metadata equality for coordinates.
+        Perform lenient equality of metadata memberss.
 
         Args:
 
@@ -262,14 +262,14 @@ def func(field):
                     result = None if left == right else (left, right)
                 return result
 
-            # Note that, we use "_fields" not "_members".
+            # Note that, for strict we use "_fields" not "_members".
             values = [func(field) for field in self._fields]
 
         return values
 
     def _difference_lenient(self, other):
         """
-        Perform lenient metadata member difference.
+        Perform lenient difference of metadata members.
 
         Args:
 
@@ -380,9 +380,11 @@ def combine(self, other, lenient=None):
             values = self._combine(other)
         else:
             if lenient:
-                args, kwargs = (self.combine,), dict()
+                # Use qualname to disassociate from the instance bounded method.
+                args, kwargs = (qualname(self.combine),), dict()
             else:
-                # Require to qualname the method to make it a hashable key.
+                # Use qualname to guarantee that the instance bounded method
+                # is a hashable key.
                 args, kwargs = (), {qualname(self.combine): False}
 
             with LENIENT.context(*args, **kwargs):
@@ -426,9 +428,11 @@ def difference(self, other, lenient=None):
             values = self._difference(other)
         else:
             if lenient:
-                args, kwargs = (self.difference,), dict()
+                # Use qualname to disassociate from the instance bounded method.
+                args, kwargs = (qualname(self.difference),), dict()
             else:
-                # Require to qualname the method to make it a hashable key.
+                # Use qualname to guarantee that the instance bounded method
+                # is a hashable key.
                 args, kwargs = (), {qualname(self.difference): False}
 
             with LENIENT.context(*args, **kwargs):
@@ -460,9 +464,11 @@ def equal(self, other, lenient=None):
             result = self.__eq__(other)
         else:
             if lenient:
-                args, kwargs = (self.equal,), dict()
+                # Use qualname to disassociate from the instance bounded method.
+                args, kwargs = (qualname(self.equal),), dict()
             else:
-                # Require to qualname the method to make it a hashable key.
+                # Use qualname to guarantee that the instance bounded method
+                # is a hashable key.
                 args, kwargs = (), {qualname(self.equal): False}
 
             with LENIENT.context(*args, **kwargs):
@@ -580,7 +586,7 @@ def __eq__(self, other):
 
     def _combine_lenient(self, other):
         """
-        Perform lenient metadata member combination for cell measures.
+        Perform lenient combination of metadata members for cell measures.
 
         Args:
 
@@ -602,7 +608,7 @@ def _combine_lenient(self, other):
 
     def _compare_lenient(self, other):
         """
-        Perform lenient metadata equality for cell measures.
+        Perform lenient equality of metadata members for cell measures.
 
         Args:
 
@@ -624,7 +630,7 @@ def _compare_lenient(self, other):
 
     def _difference_lenient(self, other):
         """
-        Perform lenient metadata member difference for cell measures.
+        Perform lenient difference of metadata members for cell measures.
 
         Args:
 
@@ -681,7 +687,7 @@ def __eq__(self, other):
 
     def _combine_lenient(self, other):
         """
-        Perform lenient metadata member combination for coordinates.
+        Perform lenient combination of metadata members for coordinates.
 
         Args:
 
@@ -707,7 +713,7 @@ def func(field):
 
     def _compare_lenient(self, other):
         """
-        Perform lenient metadata equality for coordinates.
+        Perform lenient equality of metadata members for coordinates.
 
         Args:
 
@@ -732,7 +738,7 @@ def _compare_lenient(self, other):
 
     def _difference_lenient(self, other):
         """
-        Perform lenient metadata member difference for coordinates.
+        Perform lenient differnece of metadata members for coordinates.
 
         Args:
 
@@ -790,7 +796,7 @@ def __eq__(self, other):
 
     def _combine_lenient(self, other):
         """
-        Perform lenient metadata member combination for cubes.
+        Perform lenient combination of metadata members for cubes.
 
         Args:
 
@@ -815,7 +821,7 @@ def _combine_lenient(self, other):
 
     def _compare_lenient(self, other):
         """
-        Perform lenient metadata equality for cubes.
+        Perform lenient equality of metadata members for cubes.
 
         Args:
 
@@ -835,7 +841,7 @@ def _compare_lenient(self, other):
 
     def _difference_lenient(self, other):
         """
-        Perform lenient metadata member difference for cubes.
+        Perform lenient difference of metadata members for cubes.
 
         Args:
 

lib/iris/tests/unit/common/lenient/test_Lenient.py

@@ -467,9 +467,7 @@ def client():
 
     def test_enable(self):
         enable = "enable"
-        self.assertEqual(
-            self.lenient.__dict__[enable], LENIENT_ENABLE_DEFAULT
-        )
+        self.assertEqual(self.lenient.__dict__[enable], LENIENT_ENABLE_DEFAULT)
         self.lenient[enable] = True
         self.assertTrue(self.lenient.__dict__[enable])
         self.lenient[enable] = False
@@ -666,6 +664,27 @@ def test_services_empty(self):
         with self.assertRaisesRegex(ValueError, emsg):
             self.lenient.register_client("client", ())
 
+    def test_services_overwrite(self):
+        client = "client"
+        services = ("service1", "service2")
+        self.lenient.__dict__[client] = services
+        self.assertEqual(self.lenient[client], services)
+        new_services = ("service3", "service4")
+        self.lenient.register_client(client, services=new_services)
+        self.assertEqual(self.lenient[client], new_services)
+
+    def test_services_append(self):
+        client = "client"
+        services = ("service1", "service2")
+        self.lenient.__dict__[client] = services
+        self.assertEqual(self.lenient[client], services)
+        new_services = ("service3", "service4")
+        self.lenient.register_client(
+            client, services=new_services, append=True
+        )
+        expected = set(services + new_services)
+        self.assertEqual(set(self.lenient[client]), expected)
+
 
 class Test_register_service(tests.IrisTest):
     def setUp(self):