Add code action for incorrect field names

Author: dyniec

haskell-language-server.cabal

@@ -242,6 +242,7 @@ library hls-cabal-plugin
     Ide.Plugin.Cabal.Completion.Completions
     Ide.Plugin.Cabal.Completion.Data
     Ide.Plugin.Cabal.Completion.Types
+    Ide.Plugin.Cabal.FieldSuggest
     Ide.Plugin.Cabal.LicenseSuggest
     Ide.Plugin.Cabal.Orphans
     Ide.Plugin.Cabal.Parse

plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal.hs

@@ -40,6 +40,7 @@ import qualified Ide.Plugin.Cabal.Completion.Types           as Types
 import qualified Ide.Plugin.Cabal.Diagnostics                as Diagnostics
 import qualified Ide.Plugin.Cabal.LicenseSuggest             as LicenseSuggest
 import           Ide.Plugin.Cabal.Orphans                    ()
+import qualified Ide.Plugin.Cabal.FieldSuggest               as FieldSuggest
 import qualified Ide.Plugin.Cabal.Parse                      as Parse
 import           Ide.Types
 import qualified Language.LSP.Protocol.Lens                  as JL
@@ -89,6 +90,7 @@ descriptor recorder plId =
         mconcat
           [ mkPluginHandler LSP.SMethod_TextDocumentCodeAction licenseSuggestCodeAction
           , mkPluginHandler LSP.SMethod_TextDocumentCompletion $ completion recorder
+          , mkPluginHandler LSP.SMethod_TextDocumentCodeAction fieldSuggestCodeAction
           ]
     , pluginNotificationHandlers =
         mconcat
@@ -238,6 +240,10 @@ licenseSuggestCodeAction ideState _ (CodeActionParams _ _ (TextDocumentIdentifie
   maxCompls <- fmap maxCompletions . liftIO $ runAction "cabal-plugin.suggestLicense" ideState getClientConfigAction
   pure $ InL $ diags >>= (fmap InR . LicenseSuggest.licenseErrorAction maxCompls uri)
 
+fieldSuggestCodeAction :: PluginMethodHandler IdeState 'LSP.Method_TextDocumentCodeAction
+fieldSuggestCodeAction _ _ (CodeActionParams _ _ (TextDocumentIdentifier uri) _range CodeActionContext{_diagnostics=diags}) =
+  pure $ InL $ diags >>= (fmap InR . FieldSuggest.fieldErrorAction uri)
+
 -- ----------------------------------------------------------------
 -- Cabal file of Interest rules and global variable
 -- ----------------------------------------------------------------

plugins/hls-cabal-plugin/src/Ide/Plugin/Cabal/FieldSuggest.hs

@@ -0,0 +1,70 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE ExplicitNamespaces  #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE LambdaCase          #-}
+{-# LANGUAGE OverloadedStrings   #-}
+module Ide.Plugin.Cabal.FieldSuggest
+( fieldErrorSuggestion
+, fieldErrorAction
+  -- * Re-exports
+, T.Text
+, Diagnostic(..)
+)
+where
+
+import qualified Data.Map.Strict             as Map
+import qualified Data.Text                   as T
+import           Language.LSP.Protocol.Types (CodeAction (CodeAction),
+                                              CodeActionKind (..),
+                                              Diagnostic (..),
+                                              Position (Position),
+                                              Range (Range),
+                                              TextEdit (TextEdit), Uri,
+                                              WorkspaceEdit (WorkspaceEdit))
+import           Text.Regex.TDFA
+
+-- | Given a diagnostic returned by 'Ide.Plugin.Cabal.Diag.errorDiagnostic',
+--   if it represents an "Unknown field"-error along
+--   with a incorrect field, then return a 'CodeAction' for replacing the
+--   the incorrect field with the suggestion.
+--   It should be context sensitive, but for now it isn't
+fieldErrorAction
+  :: Uri
+  -- ^ File for which the diagnostic was generated
+  -> Diagnostic
+  -- ^ Output of 'Ide.Plugin.Cabal.Diag.errorDiagnostic'
+  ->  [CodeAction]
+fieldErrorAction uri diag =
+  mkCodeAction <$> fieldErrorSuggestion diag
+  where
+    mkCodeAction (original, suggestion) =
+      let
+        -- Range returned by cabal here represents fragment from start of
+        -- offending identifier to end of line, we modify it to the end of identifier
+        adjustRange (Range rangeFrom@(Position line col) _) =
+          Range rangeFrom (Position line (col + fromIntegral (T.length original)))
+        title = "Replace with " <> suggestion
+        tedit = [TextEdit (adjustRange $ _range diag) suggestion]
+        edit  = WorkspaceEdit (Just $ Map.singleton uri tedit) Nothing Nothing
+      in CodeAction title (Just CodeActionKind_QuickFix) (Just []) Nothing Nothing (Just edit) Nothing Nothing
+
+-- | Given a diagnostic returned by 'Ide.Plugin.Cabal.Diag.errorDiagnostic',
+--   if it represents an "Unknown field"- error with incorrect identifier
+--   then return the suggestion (for now placeholder "name")
+--   along with the incorrect identifier.
+--
+fieldErrorSuggestion
+  :: Diagnostic
+  -- ^ Output of 'Ide.Plugin.Cabal.Diag.errorDiagnostic'
+  -> [(T.Text, T.Text)]
+  -- ^ (Original (incorrect) license identifier, suggested replacement)
+fieldErrorSuggestion diag =
+  mSuggestion (_message diag) >>= \case
+    [original] -> [(original, "name")]
+    _                      -> []
+  where
+    regex :: T.Text
+    regex = "Unknown field: \"(.*)\""
+    mSuggestion msg = getMatch <$> (msg :: T.Text) =~~ regex
+    getMatch :: (T.Text, T.Text, T.Text, [T.Text]) -> [T.Text]
+    getMatch (_, _, _, results) = results