Compute: Fix DisplayCommandBase comments for cliff Command subclass tests

As bug #1477199 describes, the wrong comment below is all over the
unit test code of OSC.

    # DisplayCommandBase.take_action() returns two tuples

There is no such class named DisplayCommandBase in OSC. It is in cliff.

All OSC command classes inherit from the base classes in cliff,
class Command, class Lister and class ShowOne. It is like this:

Object
|--> Command
     |--> DisplayCommandBase
         |--> Lister
         |--> ShowOne

take_action() is an abstract method of class Command, and generally is
overwritten by subclasses.

* Command.take_action() returns nothing.
* Lister.take_action() returns a tuple which contains a tuple of
  columns and a generator used to generate the data.
* ShowOne.take_action() returns an iterator which contains a tuple
  of columns and a tuple of data

So, this problem should be fixed in 3 steps:
1. Remove all DisplayCommandBase comments for tests of classes
   inheriting from class Command in cliff as it returns nothing.
2. Fix all DisplayCommandBase comments for tests of classes
   inheriting from class Lister in cliff. Lister.take_action()
   returns a tuple and a generator.
3. Fix all DisplayCommandBase comments for tests of classes
   inheriting from class ShowOne in cliff. ShowOne.take_action()
   returns two tuples.

This patch finishes step 1 in compute tests.

Change-Id: I99ab42a7de69af0e5de802a1bb5aac647245a200
Partial-bug: #1477199

Author: Tang Chen

openstackclient/tests/compute/v2/test_server.py

@@ -79,7 +79,6 @@ def run_method_with_servers(self, method_name, server_count):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         for s in servers:
@@ -411,7 +410,6 @@ def test_server_delete_no_options(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.delete.assert_called_with(
@@ -431,7 +429,6 @@ def test_server_delete_multi_servers(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         calls = []
@@ -451,7 +448,6 @@ def test_server_delete_wait_ok(self, mock_wait_for_delete):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.delete.assert_called_with(
@@ -476,7 +472,6 @@ def test_server_delete_wait_fails(self, mock_wait_for_delete):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.assertRaises(SystemExit, self.cmd.take_action, parsed_args)
 
         self.servers_mock.delete.assert_called_with(
@@ -861,7 +856,6 @@ def test_server_resize_no_options(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.get.assert_called_with(
@@ -885,7 +879,6 @@ def test_server_resize(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.get.assert_called_with(
@@ -914,7 +907,6 @@ def test_server_resize_confirm(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.get.assert_called_with(
@@ -939,7 +931,6 @@ def test_server_resize_revert(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.servers_mock.get.assert_called_with(

openstackclient/tests/compute/v2/test_service.py

@@ -49,7 +49,6 @@ def test_service_delete_no_options(self):
         ]
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
 
-        # DisplayCommandBase.take_action() returns two tuples
         self.cmd.take_action(parsed_args)
 
         self.service_mock.delete.assert_called_with(