Fix mutable default arguments in tests

Python’s default arguments are evaluated only once
when the function is defined, not each time the
function is called. This means that if you use a
mutable default argument (like list and dict) and
mutate it, you will and have mutated that object
for all future calls to the function as well.

More details about this wrong usage here:
http://docs.python-guide.org/en/latest/writing/gotchas/#mutable-default-arguments

In unit tests, most FakeXXX classes' methods take
mutable arguments with default values [] or {}.
We should change them to None.

Change-Id: Iea833b66aa1379829511ad5c6d4432b72f3488e2
Closed-bug: #1550320

1 files changed, 33 insertions, 26 deletions

diff --git a/openstackclient/tests/compute/v2/fakes.py b/openstackclient/tests/compute/v2/fakes.py
index 7f39bad0..708daaa5 100644
--- a/openstackclient/tests/compute/v2/fakes.py
+++ b/openstackclient/tests/compute/v2/fakes.py
@@ -100,8 +100,7 @@ class FakeAggregate(object):
         :return:
             A FakeResource object, with id and other attributes
         """
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
         # Set default attribute
         aggregate_info = {
@@ -217,7 +216,7 @@ class FakeHypervisor(object):
     """Fake one or more hypervisor."""
 
     @staticmethod
-    def create_one_hypervisor(attrs={}):
+    def create_one_hypervisor(attrs=None):
         """Create a fake hypervisor.
 
         :param Dictionary attrs:
@@ -225,6 +224,8 @@ class FakeHypervisor(object):
         :return:
             A FakeResource object, with id, hypervisor_hostname, and so on
         """
+        attrs = attrs or {}
+
         # Set default attributes.
         hypervisor_info = {
             'id': 'hypervisor-id-' + uuid.uuid4().hex,
@@ -263,7 +264,7 @@ class FakeHypervisor(object):
         return hypervisor
 
     @staticmethod
-    def create_hypervisors(attrs={}, count=2):
+    def create_hypervisors(attrs=None, count=2):
         """Create multiple fake hypervisors.
 
         :param Dictionary attrs:
@@ -284,7 +285,7 @@ class FakeHypervisorStats(object):
     """Fake one or more hypervisor stats."""
 
     @staticmethod
-    def create_one_hypervisor_stats(attrs={}):
+    def create_one_hypervisor_stats(attrs=None):
         """Create a fake hypervisor stats.
 
         :param Dictionary attrs:
@@ -292,6 +293,8 @@ class FakeHypervisorStats(object):
         :return:
             A FakeResource object, with id, hypervisor_hostname, and so on
         """
+        attrs = attrs or {}
+
         # Set default attributes.
         stats_info = {
             'count': 2,
@@ -319,7 +322,7 @@ class FakeHypervisorStats(object):
         return hypervisor_stats
 
     @staticmethod
-    def create_hypervisors_stats(attrs={}, count=2):
+    def create_hypervisors_stats(attrs=None, count=2):
         """Create multiple fake hypervisors stats.
 
         :param Dictionary attrs:
@@ -349,8 +352,7 @@ class FakeSecurityGroup(object):
         :return:
             A FakeResource object, with id, name, etc.
         """
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
         # Set default attributes.
         security_group_attrs = {
@@ -400,8 +402,7 @@ class FakeSecurityGroupRule(object):
         :return:
             A FakeResource object, with id, etc.
         """
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
         # Set default attributes.
         security_group_rule_attrs = {
@@ -445,7 +446,7 @@ class FakeServer(object):
     """Fake one or more compute servers."""
 
     @staticmethod
-    def create_one_server(attrs={}, methods={}):
+    def create_one_server(attrs=None, methods=None):
         """Create a fake server.
 
         :param Dictionary attrs:
@@ -455,6 +456,9 @@ class FakeServer(object):
         :return:
             A FakeResource object, with id, name, metadata
         """
+        attrs = attrs or {}
+        methods = methods or {}
+
         # Set default attributes.
         server_info = {
             'id': 'server-id-' + uuid.uuid4().hex,
@@ -477,7 +481,7 @@ class FakeServer(object):
         return server
 
     @staticmethod
-    def create_servers(attrs={}, methods={}, count=2):
+    def create_servers(attrs=None, methods=None, count=2):
         """Create multiple fake servers.
 
         :param Dictionary attrs:
@@ -527,8 +531,7 @@ class FakeFlavor(object):
         :return:
             A FakeResource object, with id, name, ram, vcpus, properties
         """
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
         # Set default attributes.
         flavor_info = {
@@ -566,7 +569,7 @@ class FakeFlavor(object):
         return flavor
 
     @staticmethod
-    def create_flavors(attrs={}, count=2):
+    def create_flavors(attrs=None, count=2):
         """Create multiple fake flavors.
 
         :param Dictionary attrs:
@@ -614,10 +617,9 @@ class FakeKeypair(object):
         :return:
             A FakeResource
         """
-        # Set default attributes.
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
+        # Set default attributes.
         keypair_info = {
             'name': 'keypair-name-' + uuid.uuid4().hex,
             'fingerprint': 'dummy',
@@ -658,7 +660,7 @@ class FakeAvailabilityZone(object):
     """Fake one or more compute availability zones (AZs)."""
 
     @staticmethod
-    def create_one_availability_zone(attrs={}):
+    def create_one_availability_zone(attrs=None):
         """Create a fake AZ.
 
         :param Dictionary attrs:
@@ -666,6 +668,8 @@ class FakeAvailabilityZone(object):
         :return:
             A FakeResource object with zoneName, zoneState, etc.
         """
+        attrs = attrs or {}
+
         # Set default attributes.
         host_name = uuid.uuid4().hex
         service_name = uuid.uuid4().hex
@@ -689,7 +693,7 @@ class FakeAvailabilityZone(object):
         return availability_zone
 
     @staticmethod
-    def create_availability_zones(attrs={}, count=2):
+    def create_availability_zones(attrs=None, count=2):
         """Create multiple fake AZs.
 
         :param Dictionary attrs:
@@ -712,7 +716,7 @@ class FakeFloatingIP(object):
     """Fake one or more floating ip."""
 
     @staticmethod
-    def create_one_floating_ip(attrs={}):
+    def create_one_floating_ip(attrs=None):
         """Create a fake floating ip.
 
         :param Dictionary attrs:
@@ -720,6 +724,8 @@ class FakeFloatingIP(object):
         :return:
             A FakeResource object, with id, ip, and so on
         """
+        attrs = attrs or {}
+
         # Set default attributes.
         floating_ip_attrs = {
             'id': 'floating-ip-id-' + uuid.uuid4().hex,
@@ -739,7 +745,7 @@ class FakeFloatingIP(object):
         return floating_ip
 
     @staticmethod
-    def create_floating_ips(attrs={}, count=2):
+    def create_floating_ips(attrs=None, count=2):
         """Create multiple fake floating ips.
 
         :param Dictionary attrs:
@@ -778,7 +784,7 @@ class FakeNetwork(object):
     """Fake one or more networks."""
 
     @staticmethod
-    def create_one_network(attrs={}):
+    def create_one_network(attrs=None):
         """Create a fake network.
 
         :param Dictionary attrs:
@@ -786,6 +792,8 @@ class FakeNetwork(object):
         :return:
             A FakeResource object, with id, label, cidr and so on
         """
+        attrs = attrs or {}
+
         # Set default attributes.
         network_attrs = {
             'bridge': 'br100',
@@ -831,7 +839,7 @@ class FakeNetwork(object):
         return network
 
     @staticmethod
-    def create_networks(attrs={}, count=2):
+    def create_networks(attrs=None, count=2):
         """Create multiple fake networks.
 
         :param Dictionary attrs:
@@ -860,8 +868,7 @@ class FakeHost(object):
         :return:
             A FakeResource object, with id and other attributes
         """
-        if attrs is None:
-            attrs = {}
+        attrs = attrs or {}
 
         # Set default attributes.
         host_info = {