From f0945d0b3b1fd00b920698d165e08f161a7ab0e8 Mon Sep 17 00:00:00 2001
From: Andreas Louv <andreas@louv.dk>
Date: Sat, 20 May 2023 21:38:34 +0200
Subject: [PATCH] Add the server config "processDiagHandler"

---
 autoload/lsp/diag.vim      | 7 ++++++-
 autoload/lsp/lsp.vim       | 6 ++++++
 autoload/lsp/lspserver.vim | 2 ++
 doc/lsp.txt                | 7 +++++++
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/autoload/lsp/diag.vim b/autoload/lsp/diag.vim
index f812c40..cf74879 100644
--- a/autoload/lsp/diag.vim
+++ b/autoload/lsp/diag.vim
@@ -251,7 +251,7 @@ enddef
 # process a diagnostic notification message from the LSP server
 # Notification: textDocument/publishDiagnostics
 # Param: PublishDiagnosticsParams
-export def DiagNotification(lspserver: dict<any>, uri: string, newDiags: list<dict<any>>): void
+export def DiagNotification(lspserver: dict<any>, uri: string, diags_arg: list<dict<any>>): void
   # Diagnostics are disabled for this server
   if lspserver.features->has_key('diagnostics') && !lspserver.features.diagnostics
     return
@@ -264,6 +264,11 @@ export def DiagNotification(lspserver: dict<any>, uri: string, newDiags: list<di
     return
   endif
 
+  var newDiags: list<dict<any>> = diags_arg
+  if lspserver.processDiagHandler != null_function
+    newDiags = lspserver.processDiagHandler(diags_arg)
+  endif
+
   # TODO: Is the buffer (bnr) always a loaded buffer? Should we load it here?
   var lastlnum: number = bnr->getbufinfo()[0].linecount
 
diff --git a/autoload/lsp/lsp.vim b/autoload/lsp/lsp.vim
index b2f6dd3..edecb3f 100644
--- a/autoload/lsp/lsp.vim
+++ b/autoload/lsp/lsp.vim
@@ -612,6 +612,11 @@ export def AddServer(serverList: list<dict<any>>)
       customNotificationHandlers = server.customNotificationHandlers
     endif
 
+    var ProcessDiagHandler: func = null_function
+    if server->has_key('processDiagHandler')
+      ProcessDiagHandler = server.processDiagHandler
+    endif
+
     var features: dict<bool> = {}
     if server->has_key('features')
       features = server.features
@@ -661,6 +666,7 @@ export def AddServer(serverList: list<dict<any>>)
 						    server.runIfSearch,
 						    server.runUnlessSearch,
 						    customNotificationHandlers,
+						    ProcessDiagHandler,
 						    features, server.debug)
 
     var ftypes = server.filetype
diff --git a/autoload/lsp/lspserver.vim b/autoload/lsp/lspserver.vim
index 89501a2..ccd3c4d 100644
--- a/autoload/lsp/lspserver.vim
+++ b/autoload/lsp/lspserver.vim
@@ -1505,6 +1505,7 @@ export def NewLspServer(name_arg: string, path_arg: string, args: list<string>,
 			runIfSearchFiles: list<any>,
 			runUnlessSearchFiles: list<any>,
 			customNotificationHandlers: dict<func>,
+			ProcessDiagHandler: func,
 			features: dict<bool>, debug_arg: bool): dict<any>
   var lspserver: dict<any> = {
     id: GetUniqueServerId(),
@@ -1514,6 +1515,7 @@ export def NewLspServer(name_arg: string, path_arg: string, args: list<string>,
     syncInit: isSync,
     initializationOptions: initializationOptions,
     customNotificationHandlers: customNotificationHandlers,
+    processDiagHandler: ProcessDiagHandler,
     features: features,
     running: false,
     ready: false,
diff --git a/doc/lsp.txt b/doc/lsp.txt
index 7ce342a..2cf47b7 100644
--- a/doc/lsp.txt
+++ b/doc/lsp.txt
@@ -320,6 +320,13 @@ Additionally the following configurations can be made:
 	omnicompl	(Optional) a boolean value that enables (true)
 			or disables (false) omni-completion for this file
 			types. By default this is set to "v:true".
+						*lsp-cfg-processDiagHandler*
+	processDiagHandler
+			(Optional) A |Funcref| or |lambda| that takes a list of
+			language server diagnostics and returns a new list of
+			filtered, or otherwise changed diagnostics.  Can be used
+			to remove unwanted diagnostics, prefix the diagnostics
+			text, etc.
 						*lsp-cfg-syncInit*
 	syncInit        (Optional) for language servers (e.g. rust analyzer,
 			gopls, etc.) that take time to initialize and reply to
-- 
2.48.1