Add handler for 'documentDidClose' (#2613)

* Add handler for 'documentDidClose'

* Update dhall-lsp-server/src/Dhall/LSP/Handlers.hs

---------

Co-authored-by: Mann mit Hut <mmhat@users.noreply.github.com>

Author: ShrykeWindgrace

dhall-lsp-server/src/Dhall/LSP/Handlers.hs

@@ -641,6 +641,11 @@ cancelationHandler :: Handlers HandlerM
 cancelationHandler =
     LSP.notificationHandler SMethod_CancelRequest \_ -> return ()
 
+-- This handler is a stub to prevent `lsp:no handler for:` messages.
+documentDidCloseHandler :: Handlers HandlerM
+documentDidCloseHandler =
+    LSP.notificationHandler SMethod_TextDocumentDidClose \_ -> return ()
+
 handleErrorWithDefault :: (Either a1 b -> HandlerM a2)
  -> b
  -> HandlerM a2

dhall-lsp-server/src/Dhall/LSP/Server.hs

@@ -22,6 +22,7 @@ import Dhall.LSP.Handlers
     , workspaceChangeConfigurationHandler
     , textDocumentChangeHandler
     , cancelationHandler
+    , documentDidCloseHandler
     )
 import Dhall.LSP.State
 import Language.LSP.Server (LspServerLog, Options(..), ServerDefinition(..), type (<~>)(..))
@@ -92,6 +93,7 @@ run = withLogger $ \ioLogger -> do
           , workspaceChangeConfigurationHandler
           , textDocumentChangeHandler
           , cancelationHandler
+          , documentDidCloseHandler
           ]
 
   let interpretHandler environment = Iso{..}