Trigger completion after dot (#313)

* Trigger completion after dot

* Fix stupid mistake in test

src/Development/IDE/LSP/Completions.hs

@@ -22,7 +22,10 @@ getCompletionsLSP
     -> IdeState
     -> CompletionParams
     -> IO CompletionResponseResult
-getCompletionsLSP lsp ide CompletionParams{_textDocument=TextDocumentIdentifier uri,_position=position} = do
+getCompletionsLSP lsp ide
+  CompletionParams{_textDocument=TextDocumentIdentifier uri
+                  ,_position=position
+                  ,_context=completionContext} = do
     contents <- LSP.getVirtualFileFunc lsp $ toNormalizedUri uri
     case (contents, uriToFilePath' uri) of
       (Just cnts, Just path) -> do
@@ -32,8 +35,10 @@ getCompletionsLSP lsp ide CompletionParams{_textDocument=TextDocumentIdentifier
           Just ((cci', tm'), mapping) -> do
             let position' = fromCurrentPosition mapping position
             pfix <- maybe (return Nothing) (flip VFS.getCompletionPrefix cnts) position'
-            case pfix of
-              Just pfix' -> do
+            case (pfix, completionContext) of
+              (Just (VFS.PosPrefixInfo _ "" _ _), Just CompletionContext { _triggerCharacter = Just "."})
+                -> return (Completions $ List [])
+              (Just pfix', _) -> do
                 let fakeClientCapabilities = ClientCapabilities Nothing Nothing Nothing Nothing
                 Completions . List <$> getCompletions ideOpts cci' (tmrModule tm') pfix' fakeClientCapabilities (WithSnippets True)
               _ -> return (Completions $ List [])

src/Development/IDE/LSP/LanguageServer.hs

@@ -206,6 +206,7 @@ data Message
 modifyOptions :: LSP.Options -> LSP.Options
 modifyOptions x = x{ LSP.textDocumentSync   = Just $ tweakTDS origTDS
                    , LSP.executeCommandCommands = Just ["typesignature.add"]
+                   , LSP.completionTriggerCharacters = Just "."
                    }
     where
         tweakTDS tds = tds{_openClose=Just True, _change=Just TdSyncIncremental, _save=Just $ SaveOptions Nothing}

test/exe/Main.hs

@@ -67,7 +67,7 @@ initializeResponseTests = withResource acquire release tests where
     testGroup "initialize response capabilities"
     [ chk "   text doc sync"             _textDocumentSync  tds
     , chk "   hover"                         _hoverProvider (Just True)
-    , chk "   completion"               _completionProvider (Just $ CompletionOptions (Just False) Nothing Nothing)
+    , chk "   completion"               _completionProvider (Just $ CompletionOptions (Just False) (Just ["."]) Nothing)
     , chk "NO signature help"        _signatureHelpProvider  Nothing
     , chk "   goto definition"          _definitionProvider (Just True)
     , chk "NO goto type definition" _typeDefinitionProvider (Just $ GotoOptionsStatic False)