Use completionSnippetsOn flag (#1195)

* Use completionSnippetsOn flag

* Enable testCase "respects lsp configuration"

* Update README: haskell.completionSnippetsOn is worked now

Co-authored-by: Junyoung/Clare Jang <jjc9310@gmail.com>

README.md

@@ -295,7 +295,7 @@ Here is a list of the additional settings currently supported by `haskell-langua
 - Format on imports (`haskell.formatOnImportOn`, default true): whether to format after adding an import
 - Maximum number of problems to report (`haskell.maxNumberOfProblems`, default 100): the maximum number of problems the server will send to the client
 - Diagnostics on change (`haskell.diagnosticsOnChange`, default true): (currently unused)
-- Completion snippets (`haskell.completionSnippetsOn`, default true): whether to support completion snippets (currently unused until we have snippets to provide)
+- Completion snippets (`haskell.completionSnippetsOn`, default true): whether to support completion snippets
 - Liquid Haskell (`haskell.liquidOn`, default false): whether to enable Liquid Haskell support (currently unused until the Liquid Haskell support is functional again)
 - Hlint (`haskell.hlintOn`, default true): whether to enable Hlint support
 

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

@@ -30,12 +30,14 @@ import Development.IDE.GHC.Util
 import Development.IDE.LSP.Server
 import TcRnDriver (tcRnImportDecls)
 import Data.Maybe
+import Ide.Plugin.Config (Config(completionSnippetsOn))
+import Ide.PluginUtils (getClientConfig)
 
 #if defined(GHC_LIB)
 import Development.IDE.Import.DependencyInformation
 #endif
 
-plugin :: Plugin c
+plugin :: Plugin Config
 plugin = Plugin produceCompletions setHandlersCompletion
 
 produceCompletions :: Rules ()
@@ -116,7 +118,7 @@ instance Binary   NonLocalCompletions
 
 -- | Generate code actions.
 getCompletionsLSP
-    :: LSP.LspFuncs cofd
+    :: LSP.LspFuncs Config
     -> IdeState
     -> CompletionParams
     -> IO (Either ResponseError CompletionResponseResult)
@@ -142,12 +144,13 @@ getCompletionsLSP lsp ide
                 -> return (Completions $ List [])
               (Just pfix', _) -> do
                 let clientCaps = clientCapabilities $ shakeExtras ide
-                Completions . List <$> getCompletions ideOpts cci' parsedMod bindMap pfix' clientCaps (WithSnippets True)
+                snippets <- WithSnippets . completionSnippetsOn <$> getClientConfig lsp
+                Completions . List <$> getCompletions ideOpts cci' parsedMod bindMap pfix' clientCaps snippets
               _ -> return (Completions $ List [])
           _ -> return (Completions $ List [])
       _ -> return (Completions $ List [])
 
-setHandlersCompletion :: PartialHandlers c
+setHandlersCompletion :: PartialHandlers Config
 setHandlersCompletion = PartialHandlers $ \WithMessage{..} x -> return x{
     LSP.completionHandler = withResponse RspCompletion getCompletionsLSP
     }

test/functional/Completion.hs

@@ -296,8 +296,7 @@ snippetTests = testGroup "snippets" [
             item ^. insertTextFormat @?= Just Snippet
             item ^. insertText @?= Just "intersperse ${1:a} ${2:[a]}"
 
-    , ignoreTestBecause "ghcide does not support the completionSnippetsOn option" $
-      testCase "respects lsp configuration" $ runSession hlsCommand fullCaps "test/testdata/completion" $ do
+    , testCase "respects lsp configuration" $ runSession hlsCommand fullCaps "test/testdata/completion" $ do
         doc <- openDoc "Completion.hs" "haskell"
 
         let config = object [ "haskell" .= (object ["completionSnippetsOn" .= False])]