Add unit tests for ext_nodes master_tops module

tests/unit/tops/__init__.py

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+# -*- coding: utf-8 -*-

tests/unit/tops/test_ext_nodes.py

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+# -*- coding: utf-8 -*-
+'''
+Test ext_nodes master_tops module
+'''
+
+# Import python libs
+from __future__ import absolute_import, print_function, unicode_literals
+import subprocess
+import textwrap
+
+# Import Salt Testing libs
+from tests.support.unit import TestCase, skipIf
+from tests.support.mixins import LoaderModuleMockMixin
+from tests.support.mock import patch, MagicMock, NO_MOCK, NO_MOCK_REASON
+
+# Import Salt libs
+import salt.utils.stringutils
+import salt.tops.ext_nodes as ext_nodes
+
+
+class ExtNodesTestCase(TestCase, LoaderModuleMockMixin):
+    def setup_loader_modules(self):
+        return {
+            ext_nodes: {
+                '__opts__': {
+                    'master_tops': {
+                        # Since ext_nodes runs the command with shell=True,
+                        # this will keep "command not found" errors from
+                        # showing up on the console. We'll be mocking the
+                        # communicate results anyway.
+                        'ext_nodes': 'echo',
+                    }
+                }
+            }
+        }
+
+    def test_ext_nodes(self):
+        '''
+        Confirm that subprocess.Popen works as expected and does not raise an
+        exception (see https://github.com/saltstack/salt/pull/46863).
+        '''
+        stdout = salt.utils.stringutils.to_bytes(textwrap.dedent('''\
+            classes:
+              - one
+              - two'''))
+        communicate_mock = MagicMock(return_value=(stdout, None))
+        with patch.object(subprocess.Popen, 'communicate', communicate_mock):
+            ret = ext_nodes.top(opts={'id': 'foo'})
+        self.assertEqual(ret, {'base': ['one', 'two']})
+
+    def test_ext_nodes_with_environment(self):
+        '''
+        Same as above, but also tests that the matches are assigned to the proper
+        environment if one is returned by the ext_nodes command.
+        '''
+        stdout = salt.utils.stringutils.to_bytes(textwrap.dedent('''\
+            classes:
+              - one
+              - two
+            environment: dev'''))
+        communicate_mock = MagicMock(return_value=(stdout, None))
+        with patch.object(subprocess.Popen, 'communicate', communicate_mock):
+            ret = ext_nodes.top(opts={'id': 'foo'})
+        self.assertEqual(ret, {'dev': ['one', 'two']})