Factor out printing store path base names too

Better for JSON, better to test in isolation.

Author: Ericson2314

hnix-store-core/src/System/Nix/StorePath.hs

@@ -27,6 +27,8 @@ module System.Nix.StorePath
     storePathToFilePath
   , storePathToRawFilePath
   , storePathToText
+  , storePathBaseToText
+  , storePathBaseToRawFilePath
   , storePathToNarInfo
   , storePathHashPartToText
   , -- * Parsing 'StorePath's
@@ -184,14 +186,25 @@ instance Default StoreDir where
 class HasStoreDir r where
   hasStoreDir :: r -> StoreDir
 
--- | Render a 'StorePath' as a 'RawFilePath'.
-storePathToRawFilePath :: StoreDir -> StorePath -> RawFilePath
-storePathToRawFilePath storeDir StorePath{..} =
-  unStoreDir storeDir <> "/" <> hashPart <> "-" <> name
+-- | Render a 'StorePath' as a base path (without store directory).
+-- This is the relative path format: @hashPart-name@
+storePathBaseToRawFilePath :: StorePath -> RawFilePath
+storePathBaseToRawFilePath StorePath{..} =
+  hashPart <> "-" <> name
  where
   hashPart = Data.Text.Encoding.encodeUtf8 $ storePathHashPartToText storePathHash
   name     = Data.Text.Encoding.encodeUtf8 $ unStorePathName storePathName
 
+-- | Render a 'StorePath' as a base path 'Text' (without store directory).
+-- This is the relative path format: @hashPart-name@
+storePathBaseToText :: StorePath -> Text
+storePathBaseToText = Data.Text.Encoding.decodeUtf8 . storePathBaseToRawFilePath
+
+-- | Render a 'StorePath' as a 'RawFilePath'.
+storePathToRawFilePath :: StoreDir -> StorePath -> RawFilePath
+storePathToRawFilePath storeDir sp =
+  unStoreDir storeDir <> "/" <> storePathBaseToRawFilePath sp
+
 -- | Render a 'StorePath' as a 'FilePath'.
 storePathToFilePath :: StoreDir -> StorePath -> FilePath
 storePathToFilePath storeDir = Data.ByteString.Char8.unpack . storePathToRawFilePath storeDir

hnix-store-json/src/System/Nix/JSON.hs

@@ -25,7 +25,6 @@ import Data.Foldable (toList)
 import Data.Set qualified
 import Data.Some
 import Data.Text (Text)
-import Data.Text qualified
 import Data.Text.Lazy qualified
 import Data.Text.Lazy.Builder qualified
 import Deriving.Aeson
@@ -41,7 +40,7 @@ import System.Nix.Realisation (DerivationOutput(..), Realisation, RealisationWit
 import System.Nix.Realisation qualified
 import System.Nix.Signature (Signature)
 import System.Nix.Signature qualified
-import System.Nix.StorePath (StorePath, StorePathName, StorePathHashPart, storePathHash, storePathName, mkStorePathName, unStorePathName, parseBasePathFromText)
+import System.Nix.StorePath (StorePath, StorePathName, StorePathHashPart, mkStorePathName, unStorePathName, parseBasePathFromText)
 import System.Nix.StorePath qualified
 
 instance ToJSON StorePathName where
@@ -68,19 +67,8 @@ instance FromJSON StorePathHashPart where
     )
 
 instance ToJSON StorePath where
-  toJSON sp =
-    toJSON $ Data.Text.concat
-      [ System.Nix.StorePath.storePathHashPartToText (storePathHash sp)
-      , "-"
-      , System.Nix.StorePath.unStorePathName (storePathName sp)
-      ]
-
-  toEncoding sp =
-    toEncoding $ Data.Text.concat
-      [ System.Nix.StorePath.storePathHashPartToText (storePathHash sp)
-      , "-"
-      , System.Nix.StorePath.unStorePathName (storePathName sp)
-      ]
+  toJSON = toJSON . System.Nix.StorePath.storePathBaseToText
+  toEncoding = toEncoding . System.Nix.StorePath.storePathBaseToText
 
 instance FromJSON StorePath where
   parseJSON =
@@ -92,12 +80,7 @@ instance FromJSON StorePath where
     )
 
 instance ToJSONKey StorePath where
-  toJSONKey = Data.Aeson.Types.toJSONKeyText $ \sp ->
-    Data.Text.concat
-      [ System.Nix.StorePath.storePathHashPartToText (storePathHash sp)
-      , "-"
-      , System.Nix.StorePath.unStorePathName (storePathName sp)
-      ]
+  toJSONKey = Data.Aeson.Types.toJSONKeyText System.Nix.StorePath.storePathBaseToText
 
 instance FromJSONKey StorePath where
   fromJSONKey = FromJSONKeyTextParser $

hnix-store-tests/tests/StorePathSpec.hs

@@ -29,3 +29,13 @@ spec = do
         roundtrips
           (storePathToText storeDir)
           (Data.Attoparsec.Text.parseOnly $ pathParser storeDir)
+
+    prop "roundtrips using parseBasePath . storePathBaseToRawFilePath" $
+      roundtrips
+        storePathBaseToRawFilePath
+        parseBasePath
+
+    prop "roundtrips using parseBasePathFromText . storePathBaseToText" $
+      roundtrips
+        storePathBaseToText
+        parseBasePathFromText