Merge lp:~james-page/charm-helpers/disable-hookenv-config-save into lp:charm-helpers

[James Page]

Add option to allow override in hookenv of configuration implicit save.

The introduction of the implicit save in Hooks broken pretty much all unit tests
in the openstack charms which exercise hook registration directly to ensure
hooks are correctly registered.

This change allows the save to be by-passed completely.

[Tim Van Steenburgh (tvansteenburgh)]

+1 LGTM.

review: Approve

=== modified file 'charmhelpers/core/hookenv.py'
--- charmhelpers/core/hookenv.py	2014-09-08 02:28:10 +0000
+++ charmhelpers/core/hookenv.py	2014-09-23 10:45:34 +0000
@@ -486,9 +486,10 @@
             hooks.execute(sys.argv)
     """
 
-    def __init__(self):
+    def __init__(self, config_save=True):
         super(Hooks, self).__init__()
         self._hooks = {}
+        self._config_save = config_save
 
     def register(self, name, function):
         """Register a hook"""
@@ -499,9 +500,10 @@
         hook_name = os.path.basename(args[0])
         if hook_name in self._hooks:
             self._hooks[hook_name]()
-            cfg = config()
-            if cfg.implicit_save:
-                cfg.save()
+            if self._config_save:
+                cfg = config()
+                if cfg.implicit_save:
+                    cfg.save()
         else:
             raise UnregisteredHookError(hook_name)
 
 
=== modified file 'tests/core/test_hookenv.py'
--- tests/core/test_hookenv.py	2014-09-05 16:31:44 +0000
+++ tests/core/test_hookenv.py	2014-09-23 10:45:34 +0000
@@ -972,6 +972,17 @@
 
         self.assertFalse(config.save.called)
 
+    def test_config_save_disabled(self):
+        config = hookenv.config()
+        config.implicit_save = True
+
+        foo = MagicMock()
+        hooks = hookenv.Hooks(config_save=False)
+        hooks.register('foo', foo)
+        hooks.execute(['foo', 'some', 'other', 'args'])
+
+        self.assertFalse(config.save.called)
+
     def test_runs_a_registered_function(self):
         foo = MagicMock()
         hooks = hookenv.Hooks()