Add warnings and fix them in hls-cabal-fmt-plugin

Author: VeryMilkyJoe

plugins/hls-cabal-fmt-plugin/hls-cabal-fmt-plugin.cabal

@@ -14,7 +14,11 @@ category:           Development
 build-type:         Simple
 extra-source-files: LICENSE
 
+common warnings
+  ghc-options: -Wall
+
 library
+  import:           warnings
   exposed-modules:  Ide.Plugin.CabalFmt
   hs-source-dirs:   src
   build-depends:
@@ -31,6 +35,7 @@ library
   default-language: Haskell2010
 
 test-suite tests
+  import:           warnings
   type:             exitcode-stdio-1.0
   default-language: Haskell2010
   hs-source-dirs:   test

plugins/hls-cabal-fmt-plugin/src/Ide/Plugin/CabalFmt.hs

@@ -4,21 +4,13 @@ import           CabalFmt
 import           CabalFmt.Error
 import           CabalFmt.Monad
 import           CabalFmt.Options
-import           Control.Exception          (bracket_)
 import           Control.Monad.IO.Class
-import           Control.Monad.Trans.Maybe  (MaybeT, runMaybeT)
-import           Data.Maybe                 (mapMaybe, maybeToList)
-import           Data.Semigroup
-import           Data.Text                  (Text)
-import qualified Data.Text                  as T
+import qualified Data.Text              as T
 import           Data.Text.Encoding
-import           Development.IDE            hiding (pluginHandlers)
-import           Development.IDE.GHC.Compat (ModSummary (ms_hspp_opts), topDir)
+import           Development.IDE        hiding (pluginHandlers)
 import           Ide.PluginUtils
 import           Ide.Types
-import           Language.LSP.Types         as J
-import qualified Language.LSP.Types.Lens    as J
-import           System.Environment         (setEnv, unsetEnv)
+import           Language.LSP.Types     as J
 import           System.FilePath
 
 descriptor :: PluginId -> PluginDescriptor IdeState
@@ -30,7 +22,7 @@ descriptor plId = (defaultCabalPluginDescriptor plId)
 -- Formats the given source in either a given Range or the whole Document.
 -- If the provider fails an error is returned that can be displayed to the user.
 provider :: FormattingHandler IdeState
-provider ide typ contents nfp opts = liftIO $ do
+provider _ide _typ contents nfp opts = liftIO $ do
   cabalFmtOutput <- runCabalFmtIO (Just $ takeDirectory fp) cabalFmtOpts (cabalFmt fp (encodeUtf8 contents))
   case cabalFmtOutput of
     Left err -> pure $ Left (cabalErrToRespErr err)