Add skeletton for niv status

Author: nmattia

src/Niv/Cli.hs

@@ -93,6 +93,7 @@ parseCommand =
         <> Opts.command "update" parseCmdUpdate
         <> Opts.command "modify" parseCmdModify
         <> Opts.command "drop" parseCmdDrop
+        <> Opts.command "status" parseCmdStatus
     )
 
 parsePackageName :: Opts.Parser PackageName
@@ -561,6 +562,36 @@ cmdDrop packageName = \case
     li $ setSources fsj $ Sources $
       HMS.insert packageName packageSpec sources
 
+-------------------------------------------------------------------------------
+-- STATUS
+-------------------------------------------------------------------------------
+
+parseCmdStatus :: Opts.ParserInfo (NIO ())
+parseCmdStatus =
+  Opts.info
+    ( pure cmdStatus
+        <**> Opts.helper
+    )
+    $ mconcat desc
+  where
+    desc =
+      [ Opts.fullDesc,
+        Opts.progDesc "Status of niv files"
+      ]
+
+cmdStatus :: NIO ()
+cmdStatus = do
+  sjs <- sourcesJsonStatus
+  tsay $ "sources.json: " <> sjs
+  where
+    sourcesJsonStatus = do
+      fsj <- getFindSourcesJson
+      liftIO (getSourcesEither fsj) >>= \case
+        Right (fp, _) -> pure (T.pack fp)
+        Left SourcesDoesntExist -> pure "not found"
+        Left SourceIsntJSON -> pure "not json"
+        Left SpecIsntAMap -> pure "bad format, not a map"
+
 -------------------------------------------------------------------------------
 -- Files and their content
 -------------------------------------------------------------------------------

src/Niv/Sources.hs

@@ -48,15 +48,16 @@ newtype Sources
       {unSources :: HMS.HashMap PackageName PackageSpec}
   deriving newtype (FromJSON, ToJSON)
 
-getSourcesEither :: FindSourcesJson -> IO (Either SourcesError Sources)
+getSourcesEither :: FindSourcesJson -> IO (Either SourcesError (FilePath, Sources))
 getSourcesEither fsj = do
-  Dir.doesFileExist (pathNixSourcesJson fsj) >>= \case
+  let path = pathNixSourcesJson fsj
+  Dir.doesFileExist path >>= \case
     False -> pure $ Left SourcesDoesntExist
     True ->
       Aeson.decodeFileStrict (pathNixSourcesJson fsj) >>= \case
         Just value -> case valueToSources value of
           Nothing -> pure $ Left SpecIsntAMap
-          Just srcs -> pure $ Right srcs
+          Just srcs -> pure $ Right (path, srcs)
         Nothing -> pure $ Left SourceIsntJSON
   where
     valueToSources :: Aeson.Value -> Maybe Sources
@@ -76,7 +77,7 @@ getSourcesEither fsj = do
 getSources :: FindSourcesJson -> IO Sources
 getSources fsj = do
   warnIfOutdated
-  getSourcesEither fsj
+  fmap snd <$> getSourcesEither fsj
     >>= either
       ( \case
           SourcesDoesntExist -> (abortSourcesDoesntExist fsj)