Implement correct behaviour for keyword and value in different lines inside stanza in cabal files

Add tests documenting the behaviour

Author: VeryMilkyJoe

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

@@ -58,17 +58,21 @@ getContext pos ls =
           kwContext <- getKeyWordContext pos ls m
           pure (Stanza s, kwContext)
     where
-      lvlContext = findCurrentLevel (getPreviousLines pos ls)
+      lvlContext = if pos ^. JL.character == 0 then TopLevel else findCurrentLevel (getPreviousLines pos ls)
 
 -- | Takes a position, a list of lines (representing a file) and a map of keywords as keys
 --   and returns a keyword context if there is a keyword from the map before the current position
 --   in the given line list
 getKeyWordContext :: Position -> [T.Text] -> Map T.Text a -> Maybe KeyWordContext
 getKeyWordContext pos ls keywords = do
-      case fmap T.stripStart lastNonEmptyLineM of
+      case lastNonEmptyLineM of
         Nothing -> Just None
-        Just lastLine -> do
-          if not isCursorAtLineStart then
+        Just lastLine' -> do
+          let (whitespaces, lastLine) = T.span (== ' ') lastLine'
+          let keywordIndentation = T.length whitespaces
+          let cursorIndentation = fromIntegral (pos ^. JL.character)
+          -- in order to be in a keyword context the cursor needs to be indented more than the keyword
+          if  cursorIndentation > keywordIndentation then
             -- if the last thing written was a keyword without a value
             case List.find (`T.isPrefixOf` lastLine) (Map.keys keywords) of
               Nothing -> Just None
@@ -80,7 +84,6 @@ getKeyWordContext pos ls keywords = do
       cur <- currentLineM
       List.find (not . T.null . T.stripEnd) $ cur : getPreviousLines pos ls
     currentLineM = ls Extra.!? (fromIntegral $ pos ^. JL.line)
-    isCursorAtLineStart = 0 == pos ^. JL.character
 
 -- | Takes info about the current cursor position and a set of possible keywords
 --   and creates completion suggestions that fit the current input from the given list

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

@@ -97,7 +97,7 @@ completionUnitTests = testGroup "Context Tests"
     testCase "Inside Stanza - no keyword" $ do
       -- on a file, where the library stanza has been defined
       -- but no keyword is defined afterwards, the stanza context should be recognized
-      getContext  (Position 3 0) libraryStanzaData @?= Just (Stanza "library", None),
+      getContext  (Position 3 2) libraryStanzaData @?= Just (Stanza "library", None),
     testCase "Inside Stanza - keyword, no value" $ do
       -- on a file, where the library stanza and a keyword
       -- has been defined, the keyword and stanza should be recognized
@@ -123,7 +123,21 @@ completionUnitTests = testGroup "Context Tests"
       -- if a keyword, other than the cabal version keyword has been written
       -- with no value, even with multiple lines in between we can still write the
       -- value corresponding to the keyword
-      getContext (Position 5 4) topLevelData @?= Just (TopLevel, KeyWord "name:")
+      getContext (Position 5 4) topLevelData @?= Just (TopLevel, KeyWord "name:"),
+    testCase "Keyword inside stanza - cursor indented more than keyword in next line" $ do
+      -- if a keyword, other than the cabal version keyword has been written
+      -- in a stanza context with no value, then the value may be written in the next line,
+      -- when the cursor is indented more than the keyword
+      getContext (Position 5 8) libraryStanzaData @?= Just (Stanza "library", KeyWord "build-depends:"),
+    testCase "Keyword inside stanza - cursor indented less than keyword in next line" $ do
+      -- if a keyword, other than the cabal version keyword has been written
+      -- in a stanza context with no value, then the value may not be written in the next line,
+      -- when the cursor is indented less than the keyword
+      getContext (Position 5 2) libraryStanzaData @?= Just (Stanza "library", None),
+    testCase "Keyword inside stanza - cursor at start of next line" $ do
+      -- in a stanza context with no value the value may not be written in the next line,
+      -- when the cursor is not indented and we are in the toplevel context
+      getContext (Position 5 0) libraryStanzaData @?= Just (TopLevel, None)
   ]
 
 -- ------------------------------------------------------------------------
@@ -251,7 +265,8 @@ libraryStanzaData =
     "name:               simple-cabal",
     "library ",
     "",
-    "    build-depends:    "
+    "    build-depends:    ",
+    "           "
   ]
 
 topLevelData :: [Text.Text]