Support for custom root (#23)

README.md

@@ -78,16 +78,16 @@ dconf dump / > dconf.settings
 
 ### Run
 
-Once compiled and installed (via `nix-build` or `cabal new-install`), you can use it as follows:
+The easiest way is to pipe the standard input to `dconf2nix` and expect the result in the standard output:
 
 ```shell
-dconf2nix -i data/dconf.settings -o output/dconf.nix
+dconf dump / | dconf2nix > dconf.nix
 ```
 
-It is also possible to pipe the standard input to `dconf2nix` and expect the result in the standard output:
+If you have an input file instead, you can run the following command:
 
 ```shell
-dconf dump / | dconf2nix > dconf.nix
+dconf2nix -i data/dconf.settings -o output/dconf.nix
 ```
 
 Type `--help` for some more information.
@@ -96,23 +96,47 @@ Type `--help` for some more information.
 dconf2nix - Nixify dconf configuration files
 
 Usage: dconf2nix [-v|--version]
-                 [[-t|--timeout ARG] [--verbose] | (-i|--input ARG)
-                   (-o|--output ARG) [-t|--timeout ARG] [--verbose]]
+                 [[-r|--root ARG] [-t|--timeout ARG] [--verbose] |
+                   (-i|--input ARG) (-o|--output ARG) [-r|--root ARG]
+                   [-t|--timeout ARG] [--verbose]]
   Convert a dconf file into a Nix file, as expected by Home Manager.
 
 Available options:
   -h,--help                Show this help text
   -v,--version             Show the current version
+  -r,--root ARG            Custom root path. e.g.: system/locale/
   -t,--timeout ARG         Timeout in seconds for the conversion
                            process (default: 5)
   --verbose                Verbose mode (debug)
   -i,--input ARG           Path to the dconf file (input)
   -o,--output ARG          Path to the Nix output file (to be created)
+  -r,--root ARG            Custom root path. e.g.: system/locale/
   -t,--timeout ARG         Timeout in seconds for the conversion
                            process (default: 5)
   --verbose                Verbose mode (debug)
 ```
 
+#### Custom root
+
+By default, `dconf2nix` expects the root to be `/`. If you want to create a dump of a custom root, you can use the `--root` flag. For example:
+
+```shell
+dconf dump /system/locale/ | dconf2nix --root system/locale > dconf.nix
+```
+
+This will generate an output similar to the one below.
+
+```nix
+{
+  dconf.settings = {
+    "system/locale" = {
+      region = "en_US.UTF-8";
+    };
+
+  };
+}
+```
+
 ### Supported types
 
 For now, only types supported by Home Manager as specified [here](https://github.com/rycee/home-manager/blob/master/modules/lib/gvariant.nix) are supported. If there's enough interest, we might be able to work on supporting the [full specification](https://developer.gnome.org/glib/stable/gvariant-text.html).

app/Main.hs

@@ -31,7 +31,7 @@ dconf2nix (ProcessTimeout t) fa successMsg = timeout (t * 1000000) fa >>= \case
 
 main :: IO ()
 main = runArgs >>= \case
-  FileInput (FileArgs i o t v) ->
-    dconf2nix t (dconf2nixFile i o v) (Just "🚀 Successfully Nixified! ❄️")
-  StdinInput (StdinArgs t v)   ->
-    dconf2nix t (dconf2nixStdin v) Nothing
+  FileInput (FileArgs i o r t v) ->
+    dconf2nix t (dconf2nixFile i o r v) (Just "🚀 Successfully Nixified! ❄️")
+  StdinInput (StdinArgs r t v)   ->
+    dconf2nix t (dconf2nixStdin r v) Nothing

data/custom.settings

@@ -0,0 +1,6 @@
+[/]
+saved-pathbar-path='/org/gnome/desktop/input-sources/'
+saved-view='/org/gnome/desktop/input-sources/'
+window-height=709
+window-is-maximized=false
+window-width=785

data/root.settings

@@ -0,0 +1,7 @@
+[mouse]
+natural-scroll=false
+speed=-0.5
+
+[touchpad]
+tap-to-click=false
+two-finger-scrolling-enabled=true

output/custom.nix

@@ -0,0 +1,18 @@
+# Generated via dconf2nix: https://github.com/gvolpe/dconf2nix
+{ lib, ... }:
+
+let
+  mkTuple = lib.hm.gvariant.mkTuple;
+in
+{
+  dconf.settings = {
+    "ca/desrt/dconf-editor" = {
+      saved-pathbar-path = "/org/gnome/desktop/input-sources/";
+      saved-view = "/org/gnome/desktop/input-sources/";
+      window-height = 709;
+      window-is-maximized = false;
+      window-width = 785;
+    };
+
+  };
+}

output/root.nix

@@ -0,0 +1,20 @@
+# Generated via dconf2nix: https://github.com/gvolpe/dconf2nix
+{ lib, ... }:
+
+let
+  mkTuple = lib.hm.gvariant.mkTuple;
+in
+{
+  dconf.settings = {
+    "org/gnome/desktop/peripherals/mouse" = {
+      natural-scroll = false;
+      speed = -0.5;
+    };
+
+    "org/gnome/desktop/peripherals/touchpad" = {
+      tap-to-click = false;
+      two-finger-scrolling-enabled = true;
+    };
+
+  };
+}

src/CommandLine.hs

@@ -6,12 +6,9 @@ module CommandLine
   )
 where
 
+import qualified Data.Text                     as T
 import           Data.Version                   ( showVersion )
-import           DConf.Data                     ( InputFilePath(..)
-                                                , OutputFilePath(..)
-                                                , ProcessTimeout(..)
-                                                , Verbosity(..)
-                                                )
+import           DConf.Data
 import           Options.Applicative
 import           Paths_dconf2nix                ( version )
 
@@ -20,17 +17,20 @@ data Input = FileInput FileArgs | StdinInput StdinArgs
 data FileArgs = FileArgs
   { fileInput :: InputFilePath
   , fileOutput :: OutputFilePath
+  , fileRoot :: Root
   , fileTimeout :: ProcessTimeout
   , fileVerbosity :: Verbosity
   }
 
 data StdinArgs = StdinArgs
-  { stdinTimeout :: ProcessTimeout
+  { stdinRoot :: Root
+  , stdinTimeout :: ProcessTimeout
   , stdinVerbosity :: Verbosity
   }
 
 timeoutArgs :: Parser ProcessTimeout
-timeoutArgs = ProcessTimeout <$> option auto
+timeoutArgs = ProcessTimeout <$> option
+  auto
   (long "timeout" <> short 't' <> showDefault <> value 5 <> help
     "Timeout in seconds for the conversion process"
   )
@@ -39,6 +39,12 @@ verbosityArgs :: Parser Verbosity
 verbosityArgs =
   flag Normal Verbose (long "verbose" <> help "Verbose mode (debug)")
 
+rootArgs :: Parser Root
+rootArgs = Root <$> strOption
+  (long "root" <> short 'r' <> value T.empty <> help
+    "Custom root path. e.g.: system/locale/"
+  )
+
 fileArgs :: Parser Input
 fileArgs = fmap FileInput $ FileArgs
     <$> (InputFilePath <$> strOption
@@ -49,11 +55,13 @@ fileArgs = fmap FileInput $ FileArgs
             "Path to the Nix output file (to be created)"
           )
         )
+    <*> rootArgs
     <*> timeoutArgs
     <*> verbosityArgs
 
 stdinArgs :: Parser Input
-stdinArgs = StdinInput <$> (StdinArgs <$> timeoutArgs <*> verbosityArgs)
+stdinArgs =
+  StdinInput <$> (StdinArgs <$> rootArgs <*> timeoutArgs <*> verbosityArgs)
 
 versionInfo :: String
 versionInfo = unlines
@@ -76,11 +84,12 @@ versionOpt = infoOption versionInfo
 
 runArgs :: IO Input
 runArgs =
-  let opts = info
-        (helper <*> versionOpt <*> (stdinArgs <|> fileArgs))
-        (  fullDesc
-        <> progDesc
-             "Convert a dconf file into a Nix file, as expected by Home Manager."
-        <> header "dconf2nix - Nixify dconf configuration files"
-        )
+  let
+    opts = info
+      (helper <*> versionOpt <*> (stdinArgs <|> fileArgs))
+      (  fullDesc
+      <> progDesc
+           "Convert a dconf file into a Nix file, as expected by Home Manager."
+      <> header "dconf2nix - Nixify dconf configuration files"
+      )
   in  execParser opts

src/DConf/Data.hs

@@ -11,6 +11,8 @@ data Verbosity = Normal | Verbose
 
 newtype Nix = Nix { unNix :: Text } deriving Show
 
+newtype Root = Root Text deriving (Eq, Show)
+
 newtype Key = Key Text deriving (Eq, Ord, Show)
 
 data Value = S Text
@@ -28,6 +30,6 @@ type Header = Text
 type Content = Map Key Value
 
 data Entry = Entry
-  { header :: Header
-  , content :: Content
+  { entryHeader :: Header
+  , entryContent :: Content
   } deriving (Eq, Show)

src/DConf2Nix.hs

@@ -10,25 +10,26 @@ import           Text.Parsec                    ( ParseError
                                                 , runParser
                                                 )
 
-dconf2nixFile :: InputFilePath -> OutputFilePath -> Verbosity -> IO ()
-dconf2nixFile (InputFilePath input) (OutputFilePath output) v = do
+dconf2nixFile :: InputFilePath -> OutputFilePath -> Root -> Verbosity -> IO ()
+dconf2nixFile (InputFilePath input) (OutputFilePath output) root v = do
   parsed <- parseFromFile (dconfParser v) input
-  handler (T.writeFile output) (T.appendFile output) parsed
+  handler (T.writeFile output) (T.appendFile output) root parsed
 
-dconf2nixStdin :: Verbosity -> IO ()
-dconf2nixStdin v = do
+dconf2nixStdin :: Root -> Verbosity -> IO ()
+dconf2nixStdin root v = do
   input <- T.getContents
-  handler T.putStr T.putStr $ runParser (dconfParser v) () "<stdin>" input
+  handler T.putStr T.putStr root $ runParser (dconfParser v) () "<stdin>" input
 
 handler
   :: (T.Text -> IO ())
   -> (T.Text -> IO ())
+  -> Root
   -> Either ParseError [Entry]
   -> IO ()
-handler writer appender parsed = do
+handler writer appender root parsed = do
   case parsed of
     Left  err -> error $ show err
     Right xs  -> do
       writer Nix.renderHeader
-      traverse (\e -> appender (unNix $ Nix.renderEntry e)) xs
+      traverse (\e -> appender (unNix $ Nix.renderEntry e root)) xs
   appender Nix.renderFooter

src/Nix.hs

@@ -25,15 +25,22 @@ renderHeader = T.unlines
   ]
 
 renderFooter :: Header
-renderFooter = T.unlines
-  [ "  };"
-  , "}"
-  ]
+renderFooter = T.unlines ["  };", "}"]
+
+normalizeRoot :: T.Text -> T.Text
+normalizeRoot r | T.null r           = r
+                | T.isSuffixOf "/" r = T.dropWhile (== '/') r
+                | otherwise          = T.dropWhile (== '/') r <> "/"
+
+normalizeHeader :: Header -> Root -> Header
+normalizeHeader "/" (Root r) = T.dropWhileEnd (== '/') (normalizeRoot r) <> ""
+normalizeHeader h   (Root r) = normalizeRoot r <> h
 
-renderEntry :: Entry -> Nix
-renderEntry (Entry h c) =
-  let header = "    \"" <> h <> "\" = {\n"
-      body   = Map.toList c >>= \(Key k, v) ->
+renderEntry :: Entry -> Root -> Nix
+renderEntry (Entry h c) root =
+  let header =
+          "    \"" <> normalizeHeader h root <> "\" = {\n"
+      body = Map.toList c >>= \(Key k, v) ->
         T.unpack $ "      " <> k <> " = " <> unNix (renderValue v) <> "\n"
       close = "    };\n\n"
   in  Nix $ header <> T.pack body <> close

test/DConf2NixTest.hs

@@ -8,7 +8,6 @@ where
 import           Data.IORef
 import qualified Data.Text                     as T
 import qualified Data.Text.IO                  as T
-import           Data.Text                      ( Text )
 import           DConf                          ( dconfParser )
 import           DConf2Nix                      ( handler )
 import           DConf.Data
@@ -18,17 +17,44 @@ import           Text.Parsec                    ( runParser )
 prop_dconf2nix :: Property
 prop_dconf2nix = withTests (10 :: TestLimit) dconf2nix
 
-dconf2nix :: Property
-dconf2nix = property $ do
-  input  <- evalIO $ T.readFile "data/dconf.settings"
-  output <- evalIO $ T.readFile "output/dconf.nix"
-  ref    <- evalIO $ newIORef ("" :: Text)
-  evalIO $ handler (writer ref) (writer ref) (entries input)
+baseProperty :: FilePath -> FilePath -> Root -> Property
+baseProperty i o root = property $ do
+  input  <- evalIO $ T.readFile i
+  output <- evalIO $ T.readFile o
+  ref    <- evalIO $ newIORef T.empty
+  evalIO $ handler (writer ref) (writer ref) root (entries input)
   result <- evalIO $ readIORef ref
   result === output
  where
-  entries i = runParser (dconfParser Normal) () "<test>" i
+  entries = runParser (dconfParser Normal) () "<test>"
   writer ref x = modifyIORef ref (`T.append` x)
 
+dconf2nix :: Property
+dconf2nix =
+  let input  = "data/dconf.settings"
+      output = "output/dconf.nix"
+      root   = Root T.empty
+  in  baseProperty input output root
+
+prop_dconf2nix_custom_root :: Property
+prop_dconf2nix_custom_root = withTests (10 :: TestLimit) dconf2nixCustomRoot
+
+dconf2nixCustomRoot :: Property
+dconf2nixCustomRoot =
+  let input  = "data/custom.settings"
+      output = "output/custom.nix"
+      root   = Root "ca/desrt/dconf-editor"
+  in  baseProperty input output root
+
+prop_dconf2nix_root :: Property
+prop_dconf2nix_root = withTests (10 :: TestLimit) dconf2nixRoot
+
+dconf2nixRoot :: Property
+dconf2nixRoot =
+  let input  = "data/root.settings"
+      output = "output/root.nix"
+      root   = Root "org/gnome/desktop/peripherals"
+  in  baseProperty input output root
+
 dconf2nixTests :: Group
 dconf2nixTests = $$(discover)

test/DConfTest.hs

@@ -30,9 +30,9 @@ testInput = T.unlines
 
 testOutput :: Entry
 testOutput = Entry
-  { header  = "org/gnome/desktop/peripherals/mouse"
-  , content = M.fromList
-                [(Key "natural-scroll", B False), (Key "speed", D (-0.5))]
+  { entryHeader  = "org/gnome/desktop/peripherals/mouse"
+  , entryContent = M.fromList
+                     [(Key "natural-scroll", B False), (Key "speed", D (-0.5))]
   }
 
 dconfParserTests :: Group