UncheckedProperty for cmdProperty et al

* Properties that run an arbitrary command, such as cmdProperty
  and scriptProperty are converted to use UncheckedProperty, since
  they cannot tell on their own if the command truely made a change or not.
  (API Change)
  Transition guide:
  - When GHC complains about an UncheckedProperty, add:
  	`assume` MadeChange
  - Since these properties used to always return MadeChange, that
    change is always safe to make.
  - Or, if you know that the command should modifiy a file, use:
  	`changesFile` filename
* A few properties have had their Result improved, for example
  Apt.buldDep and Apt.autoRemove now check if a change was made or not.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/Propellor/Property/File.hs b/src/Propellor/Property/File.hs
index e29eceb8..56066b5b 100644
--- a/src/Propellor/Property/File.hs
+++ b/src/Propellor/Property/File.hs
@@ -158,19 +158,19 @@ f `isCopyOf` f' = property desc $ go =<< (liftIO $ tryIO $ getFileStatus f')
 
 -- | Ensures that a file/dir has the specified owner and group.
 ownerGroup :: FilePath -> User -> Group -> Property NoInfo
-ownerGroup f (User owner) (Group group) = property (f ++ " owner " ++ og) $ do
-	r <- ensureProperty $ cmdProperty "chown" [og, f]
-	if r == FailedChange
-		then return r
-		else noChange
+ownerGroup f (User owner) (Group group) = p `describe` (f ++ " owner " ++ og)
   where
+	p = cmdProperty "chown" [og, f]
+		`changesFile` f
 	og = owner ++ ":" ++ group
 
 -- | Ensures that a file/dir has the specfied mode.
 mode :: FilePath -> FileMode -> Property NoInfo
-mode f v = property (f ++ " mode " ++ show v) $ do
-	liftIO $ modifyFileMode f (const v)
-	noChange
+mode f v = p `changesFile` f
+  where
+	p = property (f ++ " mode " ++ show v) $ do
+		liftIO $ modifyFileMode f (const v)
+		return NoChange
 
 -- | A temp file to use when writing new content for a file.
 --