Add the option to skip updating the head for a hg latest state (#37002)

- Updated hg state tests

salt/states/hg.py

@@ -47,7 +47,8 @@ def latest(name,
            user=None,
            identity=None,
            force=False,
-           opts=False):
+           opts=False,
+           update_head=True):
     '''
     Make sure the repository is cloned to the given directory and is up to date
 
@@ -78,6 +79,9 @@ def latest(name,
 
     opts
         Include additional arguments and options to the hg command line
+
+    update_head
+        Should we update the head if new changes are found? Defaults to True
     '''
     ret = {'name': name, 'result': True, 'comment': '', 'changes': {}}
 
@@ -89,7 +93,7 @@ def latest(name,
             os.path.isdir('{0}/.hg'.format(target)))
 
     if is_repository:
-        ret = _update_repo(ret, name, target, clean, user, identity, rev, opts)
+        ret = _update_repo(ret, name, target, clean, user, identity, rev, opts, update_head)
     else:
         if os.path.isdir(target):
             fail = _handle_existing(ret, target, force)
@@ -108,7 +112,7 @@ def latest(name,
     return ret
 
 
-def _update_repo(ret, name, target, clean, user, identity, rev, opts):
+def _update_repo(ret, name, target, clean, user, identity, rev, opts, update_head):
     '''
     Update the repo to a given revision. Using clean passes -C to the hg up
     '''
@@ -138,6 +142,14 @@ def _update_repo(ret, name, target, clean, user, identity, rev, opts):
         ret['comment'] = err
         return ret
 
+    if update_head is False:
+        changes = 'no changes found' not in pull_out
+        if changes:
+            ret['comment'] = 'Update is probably required but update_head=False so we will skip updating.'
+        else:
+            ret['comment'] = 'No changes found and update_head=False so will skip updating.'
+        return ret
+
     if rev:
         try:
             __salt__['hg.update'](target, rev, force=clean, user=user)

tests/unit/states/hg_test.py

@@ -22,6 +22,7 @@ from salttesting.mock import (
 ensure_in_syspath('../../')
 
 hg.__opts__ = {}
+hg.__salt__ = {}
 
 
 @skipIf(NO_MOCK, NO_MOCK_REASON)
@@ -56,6 +57,70 @@ class HgTestCase(TestCase):
                     self.assertDictEqual(hg.latest("salt", target="c:\\salt"),
                                          ret)
 
+    def test_latest_update_changes(self):
+        '''
+            Test to make sure we don't update even if we have changes
+        '''
+        ret = {'changes': {}, 'comment': '',
+               'name': 'salt', 'result': True}
+        revision_mock = MagicMock(return_value='abcdef')
+        pull_mock = MagicMock(return_value='Blah.')
+        update_mock = MagicMock()
+
+        with patch.dict(hg.__salt__, {'hg.revision': revision_mock,
+                                      'hg.pull': pull_mock,
+                                      'hg.update': update_mock}):
+            mock = MagicMock(side_effect=[True, True])
+            with patch.object(os.path, 'isdir', mock):
+                mock = MagicMock(return_value=True)
+                with patch.dict(hg.__opts__, {'test': False}):
+                    with patch.object(hg, '_clone_repo', mock):
+                        self.assertDictEqual(hg.latest("salt", target="c:\\salt", update_head=True), ret)
+                        assert update_mock.called
+
+    def test_latest_no_update_changes(self):
+        '''
+            Test to make sure we don't update even if we have changes
+        '''
+        ret = {'changes': {}, 'comment': 'Update is probably required but update_head=False so we will skip updating.',
+               'name': 'salt', 'result': True}
+        revision_mock = MagicMock(return_value='abcdef')
+        pull_mock = MagicMock(return_value='Blah.')
+        update_mock = MagicMock()
+
+        with patch.dict(hg.__salt__, {'hg.revision': revision_mock,
+                                      'hg.pull': pull_mock,
+                                      'hg.update': update_mock}):
+            mock = MagicMock(side_effect=[True, True])
+            with patch.object(os.path, 'isdir', mock):
+                mock = MagicMock(return_value=True)
+                with patch.dict(hg.__opts__, {'test': False}):
+                    with patch.object(hg, '_clone_repo', mock):
+                        self.assertDictEqual(hg.latest("salt", target="c:\\salt", update_head=False), ret)
+                        assert not update_mock.called
+
+    def test_latest_no_update_no_changes(self):
+        '''
+            Test to Make sure the repository is cloned to
+            the given directory and is up to date
+        '''
+        ret = {'changes': {}, 'comment': 'No changes found and update_head=False so will skip updating.',
+               'name': 'salt', 'result': True}
+        revision_mock = MagicMock(return_value='abcdef')
+        pull_mock = MagicMock(return_value='Blah no changes found.')
+        update_mock = MagicMock()
+
+        with patch.dict(hg.__salt__, {'hg.revision': revision_mock,
+                                      'hg.pull': pull_mock,
+                                      'hg.update': update_mock}):
+            mock = MagicMock(side_effect=[True, True])
+            with patch.object(os.path, 'isdir', mock):
+                mock = MagicMock(return_value=True)
+                with patch.dict(hg.__opts__, {'test': False}):
+                    with patch.object(hg, '_clone_repo', mock):
+                        self.assertDictEqual(hg.latest("salt", target="c:\\salt", update_head=False), ret)
+                        assert not update_mock.called
+
 
 if __name__ == '__main__':
     from integration import run_tests