Return completion snippets only when client supports it (haskell/ghci…

…de#929)

* Use the real client capabilities on completions

* Return completion snippets only when supported by the client

Restored from haskell/ghcide#900

ghcide/src/Development/IDE/Core/Service.hs

@@ -56,6 +56,7 @@ initialise caps mainRule getLspId toDiags wProg wIndefProg logger debouncer opti
         toDiags
         wProg
         wIndefProg
+        caps
         logger
         debouncer
         (optShakeProfiling options)

ghcide/src/Development/IDE/Core/Shake.hs

@@ -126,6 +126,7 @@ import UniqSupply
 import PrelInfo
 import Data.Int (Int64)
 import qualified Data.HashSet as HSet
+import Language.Haskell.LSP.Types.Capabilities
 
 -- information we stash inside the shakeExtra field
 data ShakeExtras = ShakeExtras
@@ -164,6 +165,7 @@ data ShakeExtras = ShakeExtras
     ,exportsMap :: Var ExportsMap
     -- | A work queue for actions added via 'runInShakeSession'
     ,actionQueue :: ActionQueue
+    ,clientCapabilities :: ClientCapabilities
     }
 
 -- | A mapping of module name to known files
@@ -401,6 +403,7 @@ shakeOpen :: IO LSP.LspId
           -> (LSP.FromServerMessage -> IO ()) -- ^ diagnostic handler
           -> WithProgressFunc
           -> WithIndefiniteProgressFunc
+          -> ClientCapabilities
           -> Logger
           -> Debouncer NormalizedUri
           -> Maybe FilePath
@@ -409,7 +412,7 @@ shakeOpen :: IO LSP.LspId
           -> ShakeOptions
           -> Rules ()
           -> IO IdeState
-shakeOpen getLspId eventer withProgress withIndefiniteProgress logger debouncer
+shakeOpen getLspId eventer withProgress withIndefiniteProgress clientCapabilities logger debouncer
   shakeProfileDir (IdeReportProgress reportProgress) ideTesting@(IdeTesting testing) opts rules = mdo
 
     inProgress <- newVar HMap.empty

ghcide/src/Development/IDE/Plugin/Completions.hs

@@ -12,7 +12,7 @@ import Language.Haskell.LSP.Messages
 import Language.Haskell.LSP.Types
 import qualified Language.Haskell.LSP.Core as LSP
 import qualified Language.Haskell.LSP.VFS as VFS
-import Language.Haskell.LSP.Types.Capabilities
+
 import Development.Shake.Classes
 import Development.Shake
 import GHC.Generics
@@ -142,9 +142,8 @@ getCompletionsLSP lsp ide
               (Just (VFS.PosPrefixInfo _ "" _ _), Just CompletionContext { _triggerCharacter = Just "."})
                 -> return (Completions $ List [])
               (Just pfix', _) -> do
-                  -- TODO pass the real capabilities here (or remove the logic for snippets)
-                let fakeClientCapabilities = ClientCapabilities Nothing Nothing Nothing Nothing
-                Completions . List <$> getCompletions ideOpts cci' parsedMod bindMap pfix' fakeClientCapabilities (WithSnippets True)
+                let clientCaps = clientCapabilities $ shakeExtras ide
+                Completions . List <$> getCompletions ideOpts cci' parsedMod bindMap pfix' clientCaps (WithSnippets True)
               _ -> return (Completions $ List [])
           _ -> return (Completions $ List [])
       _ -> return (Completions $ List [])

ghcide/src/Development/IDE/Plugin/Completions/Logic.hs

@@ -402,10 +402,13 @@ newtype WithSnippets = WithSnippets Bool
 
 toggleSnippets :: ClientCapabilities -> WithSnippets -> CompletionItem -> CompletionItem
 toggleSnippets ClientCapabilities { _textDocument } (WithSnippets with) x
-  | with = x
+  | with && supported = x
   | otherwise = x { _insertTextFormat = Just PlainText
-                , _insertText       = Nothing
-                }
+                  , _insertText       = Nothing
+                  }
+  where
+    supported =
+      Just True == (_textDocument >>= _completion >>= _completionItem >>= _snippetSupport)
 
 -- | Returns the cached completions for the given module and position.
 getCompletions