Only complete to cabal-version at first line

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

@@ -34,7 +34,7 @@ contextToCompleter :: Context -> Completer
 contextToCompleter (TopLevel, None) =
   snippetCompleter
     <> ( constantCompleter $
-           Map.keys (cabalVersionKeyword <> cabalKeywords) ++ Map.keys stanzaKeywordMap
+           Map.keys cabalKeywords ++ Map.keys stanzaKeywordMap
        )
 -- if we are in a keyword context in the top level,
 -- we look up that keyword in the top level context and can complete its possible values
@@ -55,6 +55,11 @@ contextToCompleter (Stanza s _, KeyWord kw) =
     Just m -> case Map.lookup kw m of
       Nothing -> errorNoopCompleter (LogUnknownKeyWordInContextError kw)
       Just l  -> l
+contextToCompleter (FirstLine, None) = constantCompleter ["cabal-version:"]
+contextToCompleter (FirstLine, KeyWord kw) =
+  case Map.lookup kw (cabalVersionKeyword <> cabalKeywords) of
+    Nothing -> errorNoopCompleter (LogUnknownKeyWordInContextError kw)
+    Just l  -> l
 
 -- | Takes prefix info about the previously written text
 --  and a rope (representing a file), returns the corresponding context.
@@ -135,10 +140,13 @@ findCursorContext ::
   Context
 findCursorContext cursor parentHistory prefixText fields =
   case findFieldSection cursor fields of
-    Nothing -> (snd $ NE.head parentHistory, None)
+    Nothing
+      | cursorRow == 1 -> (FirstLine, None)
+      | otherwise -> (snd $ NE.head parentHistory, None)
     -- We found the most likely section. Now, are we starting a new section or are we completing an existing one?
     Just field@(Syntax.Field _ _) -> classifyFieldContext parentHistory cursor field
     Just section@(Syntax.Section _ args sectionFields)
+      | cursorRow == 1 -> (FirstLine, None)
       | inSameLineAsSectionName section -> (stanzaCtx, None) -- TODO: test whether keyword in same line is parsed correctly
       | getFieldName section `elem` conditionalKeywords -> findCursorContext cursor parentHistory prefixText sectionFields -- Ignore if conditionals, they are not real sections
       | otherwise ->
@@ -150,6 +158,8 @@ findCursorContext cursor parentHistory prefixText fields =
         stanzaCtx = snd $ NE.head parentHistory
         conditionalKeywords = ["if", "elif", "else"]
 
+        cursorRow = Syntax.positionRow cursor
+
 -- | Finds the cursor's context, where the cursor is already found to be in a specific field
 --
 -- Due to the way the field context is recognised for incomplete cabal files,
@@ -159,11 +169,11 @@ classifyFieldContext :: NonEmpty (Int, StanzaContext) -> Syntax.Position -> Synt
 classifyFieldContext ctx cursor field
   -- the cursor is not indented enough to be within the field
   -- but still indented enough to be within the stanza
-  | cursorColumn <= fieldColumn && minIndent <= cursorColumn = (stanzaCtx, None)
+  | cursorColumn <= fieldColumn && minIndent <= cursorColumn = (firstLineOrStanzaCtx, None)
   -- the cursor is not in the current stanza's context as it is not indented enough
   | cursorColumn < minIndent = findStanzaForColumn cursorColumn ctx
-  | cursorIsInFieldName = (stanzaCtx, None)
-  | cursorIsBeforeFieldName = (stanzaCtx, None)
+  | cursorIsInFieldName = (firstLineOrStanzaCtx, None)
+  | cursorIsBeforeFieldName = (firstLineOrStanzaCtx, None)
   | otherwise = (stanzaCtx, KeyWord (getFieldName field <> ":"))
   where
     (minIndent, stanzaCtx) = NE.head ctx
@@ -179,3 +189,5 @@ classifyFieldContext ctx cursor field
 
     cursorColumn = Syntax.positionCol cursor
     fieldColumn = Syntax.positionCol (getAnnotation field)
+
+    firstLineOrStanzaCtx = if Syntax.positionRow cursor == 1 then FirstLine else stanzaCtx

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

@@ -77,7 +77,9 @@ type Context = (StanzaContext, FieldContext)
 -- | Context inside a cabal file.
 --  Used to decide which keywords to suggest.
 data StanzaContext
-  = -- | Top level context in a cabal file such as 'author'
+  = -- | First line in a cabal file. Only cabal-version is valid here
+    FirstLine
+  | -- | Top level context in a cabal file such as 'author'
     TopLevel
   | -- | Nested context in a cabal file, such as 'library'.
     --
@@ -88,6 +90,7 @@ data StanzaContext
   deriving (Eq, Show, Read)
 
 instance Pretty StanzaContext where
+    pretty FirstLine     = "FirstLine"
     pretty TopLevel      = "TopLevel"
     pretty (Stanza t ms) = "Stanza" <+> pretty t <+> (maybe mempty pretty ms)
 

plugins/hls-cabal-plugin/test/Completer.hs

@@ -77,6 +77,31 @@ basicCompleterTests =
         let complTexts = getTextEditTexts compls
         liftIO $ assertBool "suggests f2" $ "f2.hs" `elem` complTexts
         liftIO $ assertBool "does not suggest" $ "Content.hs" `notElem` complTexts
+    , runCabalTestCaseSession "only suggest cabal-version at start of file" "" $ do
+        doc <- openDoc "empty.cabal" "cabal"
+        compls <- getCompletions doc (Position 0 0)
+        let complTexts = getTextEditTexts compls
+        liftIO $ complTexts @?= ["cabal-version:"]
+    , runCabalTestCaseSession "only suggest cabal-version at start of file with other fields" "" $ do
+        doc <- openDoc "cabal-version-missing.cabal" "cabal"
+        compls <- getCompletions doc (Position 0 0)
+        let complTexts = getTextEditTexts compls
+        liftIO $ complTexts @?= ["cabal-version:"]
+    , runCabalTestCaseSession "only suggest cabal-version at start of file with some input" "" $ do
+        doc <- openDoc "start-cabal-version.cabal" "cabal"
+        compls <- getCompletions doc (Position 0 2)
+        let complTexts = getTextEditTexts compls
+        liftIO $ complTexts @?= ["cabal-version:"]
+    , runCabalTestCaseSession "suggest field value completion in first line for fields other than cabal-version" "" $ do
+        doc <- openDoc "cabal-version-not-in-first-line.cabal" "cabal"
+        compls <- getCompletions doc (Position 0 8)
+        let complTexts = getTextEditTexts compls
+        liftIO $ complTexts @?= []
+    , runCabalTestCaseSession "Don't suggest cabal-version at lines after the first line" "" $ do
+        doc <- openDoc "cabal-version-missing.cabal" "cabal"
+        compls <- getCompletions doc (Position 2 0)
+        let complTexts = getTextEditTexts compls
+        liftIO . assertBool "cabal-version is not suggested after first line" . not $ "cabal-version:" `elem` complTexts
     , parameterisedCursorTestM "extensions completion" libraryStanzaData
         [ \_ actual -> assertBool "suggests FieldSelectors" $ "FieldSelectors" `elem` actual
         , \_ actual -> assertBool "suggests OverloadedStrings" $ "OverloadedStrings" `elem` actual

plugins/hls-cabal-plugin/test/Context.hs

@@ -13,7 +13,7 @@ import           Ide.Plugin.Cabal.Completion.Completer.Paths
 import           Ide.Plugin.Cabal.Completion.Completions
 import           Ide.Plugin.Cabal.Completion.Types           (Context,
                                                               FieldContext (KeyWord, None),
-                                                              StanzaContext (Stanza, TopLevel))
+                                                              StanzaContext (FirstLine, Stanza, TopLevel))
 import qualified Ide.Plugin.Cabal.Parse                      as Parse
 import           Test.Hls
 import           Utils                                       as T
@@ -65,7 +65,7 @@ getContextTests =
             -- for a completely empty file, the context needs to
             -- be top level without a specified keyword
             ctx <- callGetContext (Position 0 0) "" ""
-            ctx @?= (TopLevel, None)
+            ctx @?= (FirstLine, None)
         , testCase "Cabal version keyword - no value, no space after :" $ do
             -- on a file, where the keyword is already written
             -- the context should still be toplevel but the keyword should be recognized
@@ -76,7 +76,7 @@ getContextTests =
             -- but the cursor is in the middle of the keyword,
             -- we are not in a keyword context
             ctx <- callGetContext (Position 0 5) "cabal" "cabal-version:\n"
-            ctx @?= (TopLevel, None)
+            ctx @?= (FirstLine, None)
         , testCase "Cabal version keyword - no value, many spaces" $ do
             -- on a file, where the "cabal-version:" keyword is already written
             -- the context should still be top level but the keyword should be recognized
@@ -87,7 +87,7 @@ getContextTests =
             -- has not been written completely, the keyword context
             -- should still be None
             ctx <- callGetContext (Position 0 5) "cabal" "cabal"
-            ctx @?= (TopLevel, None)
+            ctx @?= (FirstLine, None)
         , testCase "Cabal version keyword - value partly written" $ do
             -- in the first line of the file, if the keyword
             -- has not been written completely, the keyword context
@@ -182,7 +182,7 @@ getContextTests =
             ctx <- callGetContext (Position 8 14) "" multiLineOptsData
             ctx @?= (Stanza "library" Nothing, KeyWord "build-depends:")
         , parameterisedCursorTest "Contexts in large testfile" multiPositionTestData
-            [ (TopLevel, None)
+            [ (FirstLine, None)
             , (TopLevel, KeyWord "cabal-version:")
             , (TopLevel, None)
             , (TopLevel, KeyWord "description:")

plugins/hls-cabal-plugin/test/testdata/cabal-version-missing.cabal

@@ -0,0 +1,2 @@
+
+name:          test-hls

plugins/hls-cabal-plugin/test/testdata/cabal-version-not-in-first-line.cabal

@@ -0,0 +1 @@
+lisence: 

plugins/hls-cabal-plugin/test/testdata/start-cabal-version.cabal

@@ -0,0 +1 @@
+ca