Add support for removing redundant qualified imports

Author: ollef

src/Development/IDE/LSP/CodeAction.hs

@@ -48,6 +48,7 @@ suggestAction contents Diagnostic{_range=_range@Range{..},..}
 --       except perhaps to import instances from `Data.List'
 --     To import instances alone, use: import Data.List()
     | "The import of " `T.isInfixOf` _message
+    || "The qualified import of " `T.isInfixOf` _message
     , " is redundant" `T.isInfixOf` _message
         = [("Remove import", [TextEdit (extendToWholeLineIfPossible contents _range) ""])]
 

test/exe/Main.hs

@@ -387,6 +387,30 @@ removeImportTests = testGroup "remove import actions"
             , "stuffB = 123"
             ]
       liftIO $ expectedContentAfterAction @=? contentAfterAction
+  , testSession "qualified redundant" $ do
+      let contentA = T.unlines
+            [ "module ModuleA where"
+            ]
+      docA <- openDoc' "ModuleA.hs" "haskell" contentA
+      let contentB = T.unlines
+            [ "{-# OPTIONS_GHC -Wunused-imports #-}"
+            , "module ModuleB where"
+            , "import qualified ModuleA"
+            , "stuffB = 123"
+            ]
+      docB <- openDoc' "ModuleB.hs" "haskell" contentB
+      _ <- waitForDiagnostics
+      [CACodeAction action@CodeAction { _title = actionTitle }]
+          <- getCodeActions docB (Range (Position 2 0) (Position 2 5))
+      liftIO $ "Remove import" @=? actionTitle
+      executeCodeAction action
+      contentAfterAction <- documentContents docB
+      let expectedContentAfterAction = T.unlines
+            [ "{-# OPTIONS_GHC -Wunused-imports #-}"
+            , "module ModuleB where"
+            , "stuffB = 123"
+            ]
+      liftIO $ expectedContentAfterAction @=? contentAfterAction
   ]
 
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