Merge remote-tracking branch 'upstream/master' into mix_20240309HEADrahm

20 files changed, 1219 insertions, 715 deletions

diff --git a/runtime/lua/vim/lsp/_changetracking.lua b/runtime/lua/vim/lsp/_changetracking.lua
index b2be53269f..265a74c8fa 100644
--- a/runtime/lua/vim/lsp/_changetracking.lua
+++ b/runtime/lua/vim/lsp/_changetracking.lua
@@ -18,14 +18,14 @@ local M = {}
 ---
 ---   None: One group for all clients
 ---   Full: One group for all clients
----   Incremental: One group per `offset_encoding`
+---   Incremental: One group per `position_encoding`
 ---
 --- Sending changes can be debounced per buffer. To simplify the implementation the
 --- smallest debounce interval is used and we don't group clients by different intervals.
 ---
 --- @class vim.lsp.CTGroup
 --- @field sync_kind integer TextDocumentSyncKind, considers config.flags.allow_incremental_sync
---- @field offset_encoding "utf-8"|"utf-16"|"utf-32"
+--- @field position_encoding "utf-8"|"utf-16"|"utf-32"
 ---
 --- @class vim.lsp.CTBufferState
 --- @field name string name of the buffer
@@ -40,13 +40,13 @@ local M = {}
 --- @class vim.lsp.CTGroupState
 --- @field buffers table<integer,vim.lsp.CTBufferState>
 --- @field debounce integer debounce duration in ms
---- @field clients table<integer, table> clients using this state. {client_id, client}
+--- @field clients table<integer, vim.lsp.Client> clients using this state. {client_id, client}
 
 ---@param group vim.lsp.CTGroup
 ---@return string
 local function group_key(group)
   if group.sync_kind == protocol.TextDocumentSyncKind.Incremental then
-    return tostring(group.sync_kind) .. '\0' .. group.offset_encoding
+    return tostring(group.sync_kind) .. '\0' .. group.position_encoding
   end
   return tostring(group.sync_kind)
 end
@@ -64,7 +64,7 @@ local state_by_group = setmetatable({}, {
 ---@param client vim.lsp.Client
 ---@return vim.lsp.CTGroup
 local function get_group(client)
-  local allow_inc_sync = vim.F.if_nil(client.flags.allow_incremental_sync, true) --- @type boolean
+  local allow_inc_sync = vim.F.if_nil(client.flags.allow_incremental_sync, true)
   local change_capability = vim.tbl_get(client.server_capabilities, 'textDocumentSync', 'change')
   local sync_kind = change_capability or protocol.TextDocumentSyncKind.None
   if not allow_inc_sync and change_capability == protocol.TextDocumentSyncKind.Incremental then
@@ -72,7 +72,7 @@ local function get_group(client)
   end
   return {
     sync_kind = sync_kind,
-    offset_encoding = client.offset_encoding,
+    position_encoding = client.offset_encoding,
   }
 end
 
@@ -273,8 +273,8 @@ local function send_changes(bufnr, sync_kind, state, buf_state)
   end
   local uri = vim.uri_from_bufnr(bufnr)
   for _, client in pairs(state.clients) do
-    if not client.is_stopped() and vim.lsp.buf_is_attached(bufnr, client.id) then
-      client.notify(protocol.Methods.textDocument_didChange, {
+    if not client:is_stopped() and vim.lsp.buf_is_attached(bufnr, client.id) then
+      client:notify(protocol.Methods.textDocument_didChange, {
         textDocument = {
           uri = uri,
           version = util.buf_versions[bufnr],
@@ -310,7 +310,7 @@ local function send_changes_for_group(bufnr, firstline, lastline, new_lastline,
     -- The contents would further change and startline/endline may no longer fit
     local changes = incremental_changes(
       buf_state,
-      group.offset_encoding,
+      group.position_encoding,
       bufnr,
       firstline,
       lastline,
diff --git a/runtime/lua/vim/lsp/_folding_range.lua b/runtime/lua/vim/lsp/_folding_range.lua
new file mode 100644
index 0000000000..66eb81db6e
--- /dev/null
+++ b/runtime/lua/vim/lsp/_folding_range.lua
@@ -0,0 +1,373 @@
+local util = require('vim.lsp.util')
+local log = require('vim.lsp.log')
+local ms = require('vim.lsp.protocol').Methods
+local api = vim.api
+
+local M = {}
+
+---@class (private) vim.lsp.folding_range.BufState
+---
+---@field version? integer
+---
+--- Never use this directly, `renew()` the cached foldinfo
+--- then use on demand via `row_*` fields.
+---
+--- Index In the form of client_id -> ranges
+---@field client_ranges table<integer, lsp.FoldingRange[]?>
+---
+--- Index in the form of row -> [foldlevel, mark]
+---@field row_level table<integer, [integer, ">" | "<"?]?>
+---
+--- Index in the form of start_row -> kinds
+---@field row_kinds table<integer, table<lsp.FoldingRangeKind, true?>?>>
+---
+--- Index in the form of start_row -> collapsed_text
+---@field row_text table<integer, string?>
+
+---@type table<integer, vim.lsp.folding_range.BufState?>
+local bufstates = {}
+
+--- Renew the cached foldinfo in the buffer.
+---@param bufnr integer
+local function renew(bufnr)
+  local bufstate = assert(bufstates[bufnr])
+
+  ---@type table<integer, [integer, ">" | "<"?]?>
+  local row_level = {}
+  ---@type table<integer, table<lsp.FoldingRangeKind, true?>?>>
+  local row_kinds = {}
+  ---@type table<integer, string?>
+  local row_text = {}
+
+  for _, ranges in pairs(bufstate.client_ranges) do
+    for _, range in ipairs(ranges) do
+      local start_row = range.startLine
+      local end_row = range.endLine
+      -- Adding folds within a single line is not supported by Nvim.
+      if start_row ~= end_row then
+        row_text[start_row] = range.collapsedText
+
+        local kind = range.kind
+        if kind then
+          local kinds = row_kinds[start_row] or {}
+          kinds[kind] = true
+          row_kinds[start_row] = kinds
+        end
+
+        for row = start_row, end_row do
+          local level = row_level[row] or { 0 }
+          level[1] = level[1] + 1
+          row_level[row] = level
+        end
+        row_level[start_row][2] = '>'
+        row_level[end_row][2] = '<'
+      end
+    end
+  end
+
+  bufstate.row_level = row_level
+  bufstate.row_kinds = row_kinds
+  bufstate.row_text = row_text
+end
+
+--- Renew the cached foldinfo then force `foldexpr()` to be re-evaluated,
+--- without opening folds.
+---@param bufnr integer
+local function foldupdate(bufnr)
+  renew(bufnr)
+  for _, winid in ipairs(vim.fn.win_findbuf(bufnr)) do
+    local wininfo = vim.fn.getwininfo(winid)[1]
+    if wininfo and wininfo.tabnr == vim.fn.tabpagenr() then
+      if vim.wo[winid].foldmethod == 'expr' then
+        vim._foldupdate(winid, 0, api.nvim_buf_line_count(bufnr))
+      end
+    end
+  end
+end
+
+--- Whether `foldupdate()` is scheduled for the buffer with `bufnr`.
+---
+--- Index in the form of bufnr -> true?
+---@type table<integer, true?>
+local scheduled_foldupdate = {}
+
+--- Schedule `foldupdate()` after leaving insert mode.
+---@param bufnr integer
+local function schedule_foldupdate(bufnr)
+  if not scheduled_foldupdate[bufnr] then
+    scheduled_foldupdate[bufnr] = true
+    api.nvim_create_autocmd('InsertLeave', {
+      buffer = bufnr,
+      once = true,
+      callback = function()
+        foldupdate(bufnr)
+        scheduled_foldupdate[bufnr] = nil
+      end,
+    })
+  end
+end
+
+---@param results table<integer,{err: lsp.ResponseError?, result: lsp.FoldingRange[]?}>
+---@type lsp.MultiHandler
+local function multi_handler(results, ctx)
+  local bufnr = assert(ctx.bufnr)
+  -- Handling responses from outdated buffer only causes performance overhead.
+  if util.buf_versions[bufnr] ~= ctx.version then
+    return
+  end
+
+  local bufstate = assert(bufstates[bufnr])
+  for client_id, result in pairs(results) do
+    if result.err then
+      log.error(result.err)
+    else
+      bufstate.client_ranges[client_id] = result.result
+    end
+  end
+  bufstate.version = ctx.version
+
+  if api.nvim_get_mode().mode:match('^i') then
+    -- `foldUpdate()` is guarded in insert mode.
+    schedule_foldupdate(bufnr)
+  else
+    foldupdate(bufnr)
+  end
+end
+
+---@param result lsp.FoldingRange[]?
+---@type lsp.Handler
+local function handler(err, result, ctx)
+  multi_handler({ [ctx.client_id] = { err = err, result = result } }, ctx)
+end
+
+--- Request `textDocument/foldingRange` from the server.
+--- `foldupdate()` is scheduled once after the request is completed.
+---@param bufnr integer
+---@param client? vim.lsp.Client The client whose server supports `foldingRange`.
+local function request(bufnr, client)
+  ---@type lsp.FoldingRangeParams
+  local params = { textDocument = util.make_text_document_params(bufnr) }
+
+  if client then
+    client:request(ms.textDocument_foldingRange, params, handler, bufnr)
+    return
+  end
+
+  if not next(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange })) then
+    return
+  end
+
+  vim.lsp.buf_request_all(bufnr, ms.textDocument_foldingRange, params, multi_handler)
+end
+
+-- NOTE:
+-- `bufstate` and event hooks are interdependent:
+-- * `bufstate` needs event hooks for correctness.
+-- * event hooks require the previous `bufstate` for updates.
+-- Since they are manually created and destroyed,
+-- we ensure their lifecycles are always synchronized.
+--
+-- TODO(ofseed):
+-- 1. Implement clearing `bufstate` and event hooks
+--    when no clients in the buffer support the corresponding method.
+-- 2. Then generalize this state management to other LSP modules.
+local augroup_setup = api.nvim_create_augroup('nvim.lsp.folding_range.setup', {})
+
+--- Initialize `bufstate` and event hooks, then request folding ranges.
+--- Manage their lifecycle within this function.
+---@param bufnr integer
+---@return vim.lsp.folding_range.BufState?
+local function setup(bufnr)
+  if not api.nvim_buf_is_loaded(bufnr) then
+    return
+  end
+
+  -- Register the new `bufstate`.
+  bufstates[bufnr] = {
+    client_ranges = {},
+    row_level = {},
+    row_kinds = {},
+    row_text = {},
+  }
+
+  -- Event hooks from `buf_attach` can't be removed externally.
+  -- Hooks and `bufstate` share the same lifecycle;
+  -- they should self-destroy if `bufstate == nil`.
+  api.nvim_buf_attach(bufnr, false, {
+    -- `on_detach` also runs on buffer reload (`:e`).
+    -- Ensure `bufstate` and hooks are cleared to avoid duplication or leftover states.
+    on_detach = function()
+      bufstates[bufnr] = nil
+      api.nvim_clear_autocmds({ buffer = bufnr, group = augroup_setup })
+    end,
+    -- Reset `bufstate` and request folding ranges.
+    on_reload = function()
+      bufstates[bufnr] = {
+        client_ranges = {},
+        row_level = {},
+        row_kinds = {},
+        row_text = {},
+      }
+      request(bufnr)
+    end,
+    --- Sync changed rows with their previous foldlevels before applying new ones.
+    on_bytes = function(_, _, _, start_row, _, _, old_row, _, _, new_row, _, _)
+      if bufstates[bufnr] == nil then
+        return true
+      end
+      local row_level = bufstates[bufnr].row_level
+      if next(row_level) == nil then
+        return
+      end
+      local row = new_row - old_row
+      if row > 0 then
+        vim._list_insert(row_level, start_row, start_row + math.abs(row) - 1, { -1 })
+        -- If the previous row ends a fold,
+        -- Nvim treats the first row after consecutive `-1`s as a new fold start,
+        -- which is not the desired behavior.
+        local prev_level = row_level[start_row - 1]
+        if prev_level and prev_level[2] == '<' then
+          row_level[start_row] = { prev_level[1] - 1 }
+        end
+      elseif row < 0 then
+        vim._list_remove(row_level, start_row, start_row + math.abs(row) - 1)
+      end
+    end,
+  })
+  api.nvim_create_autocmd('LspDetach', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      if not api.nvim_buf_is_loaded(bufnr) then
+        return
+      end
+
+      ---@type integer
+      local client_id = args.data.client_id
+      bufstates[bufnr].client_ranges[client_id] = nil
+
+      ---@type vim.lsp.Client[]
+      local clients = vim
+        .iter(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange }))
+        ---@param client vim.lsp.Client
+        :filter(function(client)
+          return client.id ~= client_id
+        end)
+        :totable()
+      if #clients == 0 then
+        bufstates[bufnr] = {
+          client_ranges = {},
+          row_level = {},
+          row_kinds = {},
+          row_text = {},
+        }
+      end
+
+      foldupdate(bufnr)
+    end,
+  })
+  api.nvim_create_autocmd('LspAttach', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      local client = assert(vim.lsp.get_client_by_id(args.data.client_id))
+      if client:supports_method(vim.lsp.protocol.Methods.textDocument_foldingRange, bufnr) then
+        request(bufnr, client)
+      end
+    end,
+  })
+  api.nvim_create_autocmd('LspNotify', {
+    group = augroup_setup,
+    buffer = bufnr,
+    callback = function(args)
+      local client = assert(vim.lsp.get_client_by_id(args.data.client_id))
+      if
+        client:supports_method(ms.textDocument_foldingRange, bufnr)
+        and (
+          args.data.method == ms.textDocument_didChange
+          or args.data.method == ms.textDocument_didOpen
+        )
+      then
+        request(bufnr, client)
+      end
+    end,
+  })
+
+  request(bufnr)
+
+  return bufstates[bufnr]
+end
+
+---@param kind lsp.FoldingRangeKind
+---@param winid integer
+local function foldclose(kind, winid)
+  vim._with({ win = winid }, function()
+    local bufnr = api.nvim_win_get_buf(winid)
+    local row_kinds = bufstates[bufnr].row_kinds
+    -- Reverse traverse to ensure that the smallest ranges are closed first.
+    for row = api.nvim_buf_line_count(bufnr) - 1, 0, -1 do
+      local kinds = row_kinds[row]
+      if kinds and kinds[kind] then
+        vim.cmd(row + 1 .. 'foldclose')
+      end
+    end
+  end)
+end
+
+---@param kind lsp.FoldingRangeKind
+---@param winid? integer
+function M.foldclose(kind, winid)
+  vim.validate('kind', kind, 'string')
+  vim.validate('winid', winid, 'number', true)
+
+  winid = winid or api.nvim_get_current_win()
+  local bufnr = api.nvim_win_get_buf(winid)
+  local bufstate = bufstates[bufnr]
+  if not bufstate then
+    return
+  end
+
+  if bufstate.version == util.buf_versions[bufnr] then
+    foldclose(kind, winid)
+    return
+  end
+  -- Schedule `foldclose()` if the buffer is not up-to-date.
+
+  if not next(vim.lsp.get_clients({ bufnr = bufnr, method = ms.textDocument_foldingRange })) then
+    return
+  end
+  ---@type lsp.FoldingRangeParams
+  local params = { textDocument = util.make_text_document_params(bufnr) }
+  vim.lsp.buf_request_all(bufnr, ms.textDocument_foldingRange, params, function(...)
+    multi_handler(...)
+    foldclose(kind, winid)
+  end)
+end
+
+---@return string
+function M.foldtext()
+  local bufnr = api.nvim_get_current_buf()
+  local lnum = vim.v.foldstart
+  local row = lnum - 1
+  local bufstate = bufstates[bufnr]
+  if bufstate and bufstate.row_text[row] then
+    return bufstate.row_text[row]
+  end
+  return vim.fn.getline(lnum)
+end
+
+---@param lnum? integer
+---@return string level
+function M.foldexpr(lnum)
+  local bufnr = api.nvim_get_current_buf()
+  local bufstate = bufstates[bufnr] or setup(bufnr)
+  if not bufstate then
+    return '0'
+  end
+
+  local row = (lnum or vim.v.lnum) - 1
+  local level = bufstate.row_level[row]
+  return level and (level[2] or '') .. (level[1] or '0') or '0'
+end
+
+return M
diff --git a/runtime/lua/vim/lsp/_meta.lua b/runtime/lua/vim/lsp/_meta.lua
index bf693ccc57..589a49c003 100644
--- a/runtime/lua/vim/lsp/_meta.lua
+++ b/runtime/lua/vim/lsp/_meta.lua
@@ -1,8 +1,8 @@
 ---@meta
 error('Cannot require a meta file')
 
----@alias lsp.Handler fun(err: lsp.ResponseError?, result: any, context: lsp.HandlerContext): ...any
----@alias lsp.MultiHandler fun(results: table<integer,{err: lsp.ResponseError?, result: any}>, context: lsp.HandlerContext): ...any
+---@alias lsp.Handler fun(err: lsp.ResponseError?, result: any, context: lsp.HandlerContext, config?: table): ...any
+---@alias lsp.MultiHandler fun(results: table<integer,{err: lsp.ResponseError?, result: any}>, context: lsp.HandlerContext, config?: table): ...any
 
 ---@class lsp.HandlerContext
 ---@field method string
diff --git a/runtime/lua/vim/lsp/_snippet_grammar.lua b/runtime/lua/vim/lsp/_snippet_grammar.lua
index 9318fefcbc..f06d6e9afd 100644
--- a/runtime/lua/vim/lsp/_snippet_grammar.lua
+++ b/runtime/lua/vim/lsp/_snippet_grammar.lua
@@ -127,6 +127,7 @@ local function node(type)
 end
 
 -- stylua: ignore
+--- @diagnostic disable-next-line: missing-fields
 local G = P({
   'snippet';
   snippet = Ct(Cg(
diff --git a/runtime/lua/vim/lsp/_tagfunc.lua b/runtime/lua/vim/lsp/_tagfunc.lua
index f75d43f373..554f0cb991 100644
--- a/runtime/lua/vim/lsp/_tagfunc.lua
+++ b/runtime/lua/vim/lsp/_tagfunc.lua
@@ -6,12 +6,12 @@ local ms = lsp.protocol.Methods
 ---@param name string
 ---@param range lsp.Range
 ---@param uri string
----@param offset_encoding string
+---@param position_encoding string
 ---@return {name: string, filename: string, cmd: string, kind?: string}
-local function mk_tag_item(name, range, uri, offset_encoding)
+local function mk_tag_item(name, range, uri, position_encoding)
   local bufnr = vim.uri_to_bufnr(uri)
   -- This is get_line_byte_from_position is 0-indexed, call cursor expects a 1-indexed position
-  local byte = util._get_line_byte_from_position(bufnr, range.start, offset_encoding) + 1
+  local byte = util._get_line_byte_from_position(bufnr, range.start, position_encoding) + 1
   return {
     name = name,
     filename = vim.uri_to_fname(uri),
@@ -32,9 +32,9 @@ local function query_definition(pattern)
 
   --- @param range lsp.Range
   --- @param uri string
-  --- @param offset_encoding string
-  local add = function(range, uri, offset_encoding)
-    table.insert(results, mk_tag_item(pattern, range, uri, offset_encoding))
+  --- @param position_encoding string
+  local add = function(range, uri, position_encoding)
+    table.insert(results, mk_tag_item(pattern, range, uri, position_encoding))
   end
 
   local remaining = #clients
@@ -59,7 +59,7 @@ local function query_definition(pattern)
       remaining = remaining - 1
     end
     local params = util.make_position_params(win, client.offset_encoding)
-    client.request(ms.textDocument_definition, params, on_response, bufnr)
+    client:request(ms.textDocument_definition, params, on_response, bufnr)
   end
   vim.wait(1000, function()
     return remaining == 0
@@ -78,11 +78,11 @@ local function query_workspace_symbols(pattern)
   local results = {}
   for client_id, responses in pairs(assert(results_by_client)) do
     local client = lsp.get_client_by_id(client_id)
-    local offset_encoding = client and client.offset_encoding or 'utf-16'
+    local position_encoding = client and client.offset_encoding or 'utf-16'
     local symbols = responses.result --[[@as lsp.SymbolInformation[]|nil]]
     for _, symbol in pairs(symbols or {}) do
       local loc = symbol.location
-      local item = mk_tag_item(symbol.name, loc.range, loc.uri, offset_encoding)
+      local item = mk_tag_item(symbol.name, loc.range, loc.uri, position_encoding)
       item.kind = lsp.protocol.SymbolKind[symbol.kind] or 'Unknown'
       table.insert(results, item)
     end
diff --git a/runtime/lua/vim/lsp/_transport.lua b/runtime/lua/vim/lsp/_transport.lua
new file mode 100644
index 0000000000..19ff2a8ab0
--- /dev/null
+++ b/runtime/lua/vim/lsp/_transport.lua
@@ -0,0 +1,182 @@
+local uv = vim.uv
+local log = require('vim.lsp.log')
+
+local is_win = vim.fn.has('win32') == 1
+
+--- Checks whether a given path exists and is a directory.
+---@param filename string path to check
+---@return boolean
+local function is_dir(filename)
+  local stat = uv.fs_stat(filename)
+  return stat and stat.type == 'directory' or false
+end
+
+--- @class (private) vim.lsp.rpc.Transport
+--- @field write fun(self: vim.lsp.rpc.Transport, msg: string)
+--- @field is_closing fun(self: vim.lsp.rpc.Transport): boolean
+--- @field terminate fun(self: vim.lsp.rpc.Transport)
+
+--- @class (private,exact) vim.lsp.rpc.Transport.Run : vim.lsp.rpc.Transport
+--- @field new fun(): vim.lsp.rpc.Transport.Run
+--- @field sysobj? vim.SystemObj
+local TransportRun = {}
+
+--- @return vim.lsp.rpc.Transport.Run
+function TransportRun.new()
+  return setmetatable({}, { __index = TransportRun })
+end
+
+--- @param cmd string[] Command to start the LSP server.
+--- @param extra_spawn_params? vim.lsp.rpc.ExtraSpawnParams
+--- @param on_read fun(err: any, data: string)
+--- @param on_exit fun(code: integer, signal: integer)
+function TransportRun:run(cmd, extra_spawn_params, on_read, on_exit)
+  local function on_stderr(_, chunk)
+    if chunk then
+      log.error('rpc', cmd[1], 'stderr', chunk)
+    end
+  end
+
+  extra_spawn_params = extra_spawn_params or {}
+
+  if extra_spawn_params.cwd then
+    assert(is_dir(extra_spawn_params.cwd), 'cwd must be a directory')
+  end
+
+  local detached = not is_win
+  if extra_spawn_params.detached ~= nil then
+    detached = extra_spawn_params.detached
+  end
+
+  local ok, sysobj_or_err = pcall(vim.system, cmd, {
+    stdin = true,
+    stdout = on_read,
+    stderr = on_stderr,
+    cwd = extra_spawn_params.cwd,
+    env = extra_spawn_params.env,
+    detach = detached,
+  }, function(obj)
+    on_exit(obj.code, obj.signal)
+  end)
+
+  if not ok then
+    local err = sysobj_or_err --[[@as string]]
+    local sfx = err:match('ENOENT')
+        and '. The language server is either not installed, missing from PATH, or not executable.'
+      or string.format(' with error message: %s', err)
+
+    error(('Spawning language server with cmd: `%s` failed%s'):format(vim.inspect(cmd), sfx))
+  end
+
+  self.sysobj = sysobj_or_err --[[@as vim.SystemObj]]
+end
+
+function TransportRun:write(msg)
+  assert(self.sysobj):write(msg)
+end
+
+function TransportRun:is_closing()
+  return self.sysobj == nil or self.sysobj:is_closing()
+end
+
+function TransportRun:terminate()
+  assert(self.sysobj):kill(15)
+end
+
+--- @class (private,exact) vim.lsp.rpc.Transport.Connect : vim.lsp.rpc.Transport
+--- @field new fun(): vim.lsp.rpc.Transport.Connect
+--- @field handle? uv.uv_pipe_t|uv.uv_tcp_t
+--- Connect returns a PublicClient synchronously so the caller
+--- can immediately send messages before the connection is established
+--- -> Need to buffer them until that happens
+--- @field connected boolean
+--- @field closing boolean
+--- @field msgbuf vim.Ringbuf
+--- @field on_exit? fun(code: integer, signal: integer)
+local TransportConnect = {}
+
+--- @return vim.lsp.rpc.Transport.Connect
+function TransportConnect.new()
+  return setmetatable({
+    connected = false,
+    -- size should be enough because the client can't really do anything until initialization is done
+    -- which required a response from the server - implying the connection got established
+    msgbuf = vim.ringbuf(10),
+    closing = false,
+  }, { __index = TransportConnect })
+end
+
+--- @param host_or_path string
+--- @param port? integer
+--- @param on_read fun(err: any, data: string)
+--- @param on_exit? fun(code: integer, signal: integer)
+function TransportConnect:connect(host_or_path, port, on_read, on_exit)
+  self.on_exit = on_exit
+  self.handle = (
+    port and assert(uv.new_tcp(), 'Could not create new TCP socket')
+    or assert(uv.new_pipe(false), 'Pipe could not be opened.')
+  )
+
+  local function on_connect(err)
+    if err then
+      local address = not port and host_or_path or (host_or_path .. ':' .. port)
+      vim.schedule(function()
+        vim.notify(
+          string.format('Could not connect to %s, reason: %s', address, vim.inspect(err)),
+          vim.log.levels.WARN
+        )
+      end)
+      return
+    end
+    self.handle:read_start(on_read)
+    self.connected = true
+    for msg in self.msgbuf do
+      self.handle:write(msg)
+    end
+  end
+
+  if not port then
+    self.handle:connect(host_or_path, on_connect)
+    return
+  end
+
+  --- @diagnostic disable-next-line:param-type-mismatch bad UV typing
+  local info = uv.getaddrinfo(host_or_path, nil)
+  local resolved_host = info and info[1] and info[1].addr or host_or_path
+  self.handle:connect(resolved_host, port, on_connect)
+end
+
+function TransportConnect:write(msg)
+  if self.connected then
+    local _, err = self.handle:write(msg)
+    if err and not self.closing then
+      log.error('Error on handle:write: %q', err)
+    end
+    return
+  end
+
+  self.msgbuf:push(msg)
+end
+
+function TransportConnect:is_closing()
+  return self.closing
+end
+
+function TransportConnect:terminate()
+  if self.closing then
+    return
+  end
+  self.closing = true
+  if self.handle then
+    self.handle:shutdown()
+    self.handle:close()
+  end
+  if self.on_exit then
+    self.on_exit(0, 0)
+  end
+end
+
+return {
+  TransportRun = TransportRun,
+  TransportConnect = TransportConnect,
+}
diff --git a/runtime/lua/vim/lsp/_watchfiles.lua b/runtime/lua/vim/lsp/_watchfiles.lua
index c4cdb5aea8..4711b3cc9b 100644
--- a/runtime/lua/vim/lsp/_watchfiles.lua
+++ b/runtime/lua/vim/lsp/_watchfiles.lua
@@ -116,7 +116,7 @@ function M.register(reg, client_id)
               local params = {
                 changes = change_queues[client_id],
               }
-              client.notify(ms.workspace_didChangeWatchedFiles, params)
+              client:notify(ms.workspace_didChangeWatchedFiles, params)
               queue_timers[client_id] = nil
               change_queues[client_id] = nil
               change_cache[client_id] = nil
@@ -174,6 +174,7 @@ function M.cancel(client_id)
       cancel()
     end
   end
+  cancels[client_id] = nil
 end
 
 return M
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 6383855a30..48aa809ebd 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -20,7 +20,7 @@ local function client_positional_params(params)
   end
 end
 
-local hover_ns = api.nvim_create_namespace('vim_lsp_hover_range')
+local hover_ns = api.nvim_create_namespace('nvim.lsp.hover_range')
 
 --- @class vim.lsp.buf.hover.Opts : vim.lsp.util.open_floating_preview.Opts
 --- @field silent? boolean
@@ -232,7 +232,7 @@ local function get_locations(method, opts)
   end
   for _, client in ipairs(clients) do
     local params = util.make_position_params(win, client.offset_encoding)
-    client.request(method, params, function(_, result)
+    client:request(method, params, function(_, result)
       on_response(_, result, client)
     end)
   end
@@ -252,13 +252,13 @@ end
 --- vim.lsp.buf.definition({ on_list = on_list })
 --- vim.lsp.buf.references(nil, { on_list = on_list })
 --- ```
+--- @field on_list? fun(t: vim.lsp.LocationOpts.OnList)
 ---
---- If you prefer loclist instead of qflist:
+--- Whether to use the |location-list| or the |quickfix| list in the default handler.
 --- ```lua
 --- vim.lsp.buf.definition({ loclist = true })
---- vim.lsp.buf.references(nil, { loclist = true })
+--- vim.lsp.buf.references(nil, { loclist = false })
 --- ```
---- @field on_list? fun(t: vim.lsp.LocationOpts.OnList)
 --- @field loclist? boolean
 
 --- @class vim.lsp.LocationOpts.OnList
@@ -324,12 +324,11 @@ local function process_signature_help_results(results)
   return signatures
 end
 
-local sig_help_ns = api.nvim_create_namespace('vim_lsp_signature_help')
+local sig_help_ns = api.nvim_create_namespace('nvim.lsp.signature_help')
 
 --- @class vim.lsp.buf.signature_help.Opts : vim.lsp.util.open_floating_preview.Opts
 --- @field silent? boolean
 
--- TODO(lewis6991): support multiple clients
 --- Displays signature information about the symbol under the cursor in a
 --- floating window.
 --- @param config? vim.lsp.buf.signature_help.Opts
@@ -356,6 +355,7 @@ function M.signature_help(config)
 
     local ft = vim.bo[ctx.bufnr].filetype
     local total = #signatures
+    local can_cycle = total > 1 and config.focusable
     local idx = 0
 
     --- @param update_win? integer
@@ -371,7 +371,7 @@ function M.signature_help(config)
         return
       end
 
-      local sfx = total > 1 and string.format(' (%d/%d) (<C-s> to cycle)', idx, total) or ''
+      local sfx = can_cycle and string.format(' (%d/%d) (<C-s> to cycle)', idx, total) or ''
       local title = string.format('Signature Help: %s%s', client.name, sfx)
       if config.border then
         config.title = title
@@ -402,7 +402,7 @@ function M.signature_help(config)
 
     local fbuf, fwin = show_signature()
 
-    if total > 1 then
+    if can_cycle then
       vim.keymap.set('n', '<C-s>', function()
         show_signature(fwin)
       end, {
@@ -423,7 +423,7 @@ end
 ---
 ---@see vim.lsp.protocol.CompletionTriggerKind
 function M.completion(context)
-  vim.depends('vim.lsp.buf.completion', 'vim.lsp.commpletion.trigger', '0.12')
+  vim.depends('vim.lsp.buf.completion', 'vim.lsp.completion.trigger', '0.12')
   return lsp.buf_request(
     0,
     ms.textDocument_completion,
@@ -450,10 +450,10 @@ local function range_from_selection(bufnr, mode)
   -- A user can start visual selection at the end and move backwards
   -- Normalize the range to start < end
   if start_row == end_row and end_col < start_col then
-    end_col, start_col = start_col, end_col
+    end_col, start_col = start_col, end_col --- @type integer, integer
   elseif end_row < start_row then
-    start_row, end_row = end_row, start_row
-    start_col, end_col = end_col, start_col
+    start_row, end_row = end_row, start_row --- @type integer, integer
+    start_col, end_col = end_col, start_col --- @type integer, integer
   end
   if mode == 'V' then
     start_col = 1
@@ -487,7 +487,7 @@ end
 --- ```lua
 --- -- Never request typescript-language-server for formatting
 --- vim.lsp.buf.format {
----   filter = function(client) return client.name ~= "tsserver" end
+---   filter = function(client) return client.name ~= "ts_ls" end
 --- }
 --- ```
 --- @field filter? fun(client: vim.lsp.Client): boolean?
@@ -519,7 +519,7 @@ end
 --- @param opts? vim.lsp.buf.format.Opts
 function M.format(opts)
   opts = opts or {}
-  local bufnr = opts.bufnr or api.nvim_get_current_buf()
+  local bufnr = vim._resolve_bufnr(opts.bufnr)
   local mode = api.nvim_get_mode().mode
   local range = opts.range
   -- Try to use visual selection if no range is given
@@ -553,27 +553,34 @@ function M.format(opts)
 
   --- @param client vim.lsp.Client
   --- @param params lsp.DocumentFormattingParams
-  --- @return lsp.DocumentFormattingParams
+  --- @return lsp.DocumentFormattingParams|lsp.DocumentRangeFormattingParams|lsp.DocumentRangesFormattingParams
   local function set_range(client, params)
-    local to_lsp_range = function(r) ---@return lsp.DocumentRangeFormattingParams|lsp.DocumentRangesFormattingParams
+    ---  @param r {start:[integer,integer],end:[integer, integer]}
+    local function to_lsp_range(r)
       return util.make_given_range_params(r.start, r['end'], bufnr, client.offset_encoding).range
     end
 
+    local ret = params --[[@as lsp.DocumentFormattingParams|lsp.DocumentRangeFormattingParams|lsp.DocumentRangesFormattingParams]]
     if passed_multiple_ranges then
-      params.ranges = vim.tbl_map(to_lsp_range, range)
+      ret = params --[[@as lsp.DocumentRangesFormattingParams]]
+      --- @cast range {start:[integer,integer],end:[integer, integer]}
+      ret.ranges = vim.tbl_map(to_lsp_range, range)
     elseif range then
-      params.range = to_lsp_range(range)
+      ret = params --[[@as lsp.DocumentRangeFormattingParams]]
+      ret.range = to_lsp_range(range)
     end
-    return params
+    return ret
   end
 
   if opts.async then
+    --- @param idx? integer
+    --- @param client? vim.lsp.Client
     local function do_format(idx, client)
-      if not client then
+      if not idx or not client then
         return
       end
       local params = set_range(client, util.make_formatting_params(opts.formatting_options))
-      client.request(method, params, function(...)
+      client:request(method, params, function(...)
         local handler = client.handlers[method] or lsp.handlers[method]
         handler(...)
         do_format(next(clients, idx))
@@ -584,7 +591,7 @@ function M.format(opts)
     local timeout_ms = opts.timeout_ms or 1000
     for _, client in pairs(clients) do
       local params = set_range(client, util.make_formatting_params(opts.formatting_options))
-      local result, err = client.request_sync(method, params, timeout_ms, bufnr)
+      local result, err = client:request_sync(method, params, timeout_ms, bufnr)
       if result and result.result then
         util.apply_text_edits(result.result, bufnr, client.offset_encoding)
       elseif err then
@@ -615,7 +622,7 @@ end
 ---@param opts? vim.lsp.buf.rename.Opts Additional options:
 function M.rename(new_name, opts)
   opts = opts or {}
-  local bufnr = opts.bufnr or api.nvim_get_current_buf()
+  local bufnr = vim._resolve_bufnr(opts.bufnr)
   local clients = lsp.get_clients({
     bufnr = bufnr,
     name = opts.name,
@@ -636,38 +643,40 @@ function M.rename(new_name, opts)
   local cword = vim.fn.expand('<cword>')
 
   --- @param range lsp.Range
-  --- @param offset_encoding string
-  local function get_text_at_range(range, offset_encoding)
+  --- @param position_encoding string
+  local function get_text_at_range(range, position_encoding)
     return api.nvim_buf_get_text(
       bufnr,
       range.start.line,
-      util._get_line_byte_from_position(bufnr, range.start, offset_encoding),
+      util._get_line_byte_from_position(bufnr, range.start, position_encoding),
       range['end'].line,
-      util._get_line_byte_from_position(bufnr, range['end'], offset_encoding),
+      util._get_line_byte_from_position(bufnr, range['end'], position_encoding),
       {}
     )[1]
   end
 
+  --- @param idx? integer
+  --- @param client? vim.lsp.Client
   local function try_use_client(idx, client)
-    if not client then
+    if not idx or not client then
       return
     end
 
     --- @param name string
     local function rename(name)
-      local params = util.make_position_params(win, client.offset_encoding)
+      local params = util.make_position_params(win, client.offset_encoding) --[[@as lsp.RenameParams]]
       params.newName = name
       local handler = client.handlers[ms.textDocument_rename]
         or lsp.handlers[ms.textDocument_rename]
-      client.request(ms.textDocument_rename, params, function(...)
+      client:request(ms.textDocument_rename, params, function(...)
         handler(...)
         try_use_client(next(clients, idx))
       end, bufnr)
     end
 
-    if client.supports_method(ms.textDocument_prepareRename) then
+    if client:supports_method(ms.textDocument_prepareRename) then
       local params = util.make_position_params(win, client.offset_encoding)
-      client.request(ms.textDocument_prepareRename, params, function(err, result)
+      client:request(ms.textDocument_prepareRename, params, function(err, result)
         if err or result == nil then
           if next(clients, idx) then
             try_use_client(next(clients, idx))
@@ -706,7 +715,7 @@ function M.rename(new_name, opts)
       end, bufnr)
     else
       assert(
-        client.supports_method(ms.textDocument_rename),
+        client:supports_method(ms.textDocument_rename),
         'Client must support textDocument/rename'
       )
       if new_name then
@@ -732,7 +741,7 @@ end
 
 --- Lists all the references to the symbol under the cursor in the quickfix window.
 ---
----@param context (table|nil) Context for the request
+---@param context lsp.ReferenceContext? Context for the request
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_references
 ---@param opts? vim.lsp.ListOpts
 function M.references(context, opts)
@@ -781,7 +790,7 @@ function M.references(context, opts)
     params.context = context or {
       includeDeclaration = true,
     }
-    client.request(ms.textDocument_references, params, function(_, result)
+    client:request(ms.textDocument_references, params, function(_, result)
       local items = util.locations_to_items(result or {}, client.offset_encoding)
       vim.list_extend(all_items, items)
       remaining = remaining - 1
@@ -792,9 +801,10 @@ function M.references(context, opts)
   end
 end
 
---- Lists all symbols in the current buffer in the quickfix window.
+--- Lists all symbols in the current buffer in the |location-list|.
 --- @param opts? vim.lsp.ListOpts
 function M.document_symbol(opts)
+  opts = vim.tbl_deep_extend('keep', opts or {}, { loclist = true })
   local params = { textDocument = util.make_text_document_params() }
   request_with_opts(ms.textDocument_documentSymbol, params, opts)
 end
@@ -813,7 +823,7 @@ local function request_with_id(client_id, method, params, handler, bufnr)
     )
     return
   end
-  client.request(method, params, handler, bufnr)
+  client:request(method, params, handler, bufnr)
 end
 
 --- @param item lsp.TypeHierarchyItem|lsp.CallHierarchyItem
@@ -880,7 +890,7 @@ local function hierarchy(method)
   for _, client in ipairs(clients) do
     local params = util.make_position_params(win, client.offset_encoding)
     --- @param result lsp.CallHierarchyItem[]|lsp.TypeHierarchyItem[]?
-    client.request(prepare_method, params, function(err, result, ctx)
+    client:request(prepare_method, params, function(err, result, ctx)
       if err then
         vim.notify(err.message, vim.log.levels.WARN)
       elseif result then
@@ -1131,8 +1141,8 @@ local function on_code_action_results(results, opts)
     local action = choice.action
     local bufnr = assert(choice.ctx.bufnr, 'Must have buffer number')
 
-    if not action.edit and client.supports_method(ms.codeAction_resolve) then
-      client.request(ms.codeAction_resolve, action, function(err, resolved_action)
+    if not action.edit and client:supports_method(ms.codeAction_resolve) then
+      client:request(ms.codeAction_resolve, action, function(err, resolved_action)
         if err then
           if action.command then
             apply_action(action, client, choice.ctx)
@@ -1224,6 +1234,7 @@ function M.code_action(opts)
   for _, client in ipairs(clients) do
     ---@type lsp.CodeActionParams
     local params
+
     if opts.range then
       assert(type(opts.range) == 'table', 'code_action range must be a table')
       local start = assert(opts.range.start, 'range must have a `start` property')
@@ -1236,6 +1247,9 @@ function M.code_action(opts)
     else
       params = util.make_range_params(win, client.offset_encoding)
     end
+
+    --- @cast params lsp.CodeActionParams
+
     if context.diagnostics then
       params.context = context
     else
@@ -1253,7 +1267,7 @@ function M.code_action(opts)
       })
     end
 
-    client.request(ms.textDocument_codeAction, params, on_result, bufnr)
+    client:request(ms.textDocument_codeAction, params, on_result, bufnr)
   end
 end
 
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index 11ecb87507..253ccc48f4 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -75,17 +75,17 @@ local validate = vim.validate
 ---
 --- Map with language server specific settings.
 --- See the {settings} in |vim.lsp.Client|.
---- @field settings? table
+--- @field settings? lsp.LSPObject
 ---
 --- Table that maps string of clientside commands to user-defined functions.
---- Commands passed to start_client take precedence over the global command registry. Each key
+--- Commands passed to `start()` take precedence over the global command registry. Each key
 --- must be a unique command name, and the value is a function which is called if any LSP action
 --- (code action, code lenses, ...) triggers the command.
 --- @field commands? table<string,fun(command: lsp.Command, ctx: table)>
 ---
 --- Values to pass in the initialization request as `initializationOptions`. See `initialize` in
 --- the LSP spec.
---- @field init_options? table
+--- @field init_options? lsp.LSPObject
 ---
 --- Name in log messages.
 --- (default: client-id)
@@ -94,7 +94,8 @@ local validate = vim.validate
 --- Language ID as string. Defaults to the buffer filetype.
 --- @field get_language_id? fun(bufnr: integer, filetype: string): string
 ---
---- The encoding that the LSP server expects. Client does not verify this is correct.
+--- Called "position encoding" in LSP spec, the encoding that the LSP server expects.
+--- Client does not verify this is correct.
 --- @field offset_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---
 --- Callback invoked when the client operation throws an error. `code` is a number describing the error.
@@ -103,7 +104,7 @@ local validate = vim.validate
 --- @field on_error? fun(code: integer, err: string)
 ---
 --- Callback invoked before the LSP "initialize" phase, where `params` contains the parameters
---- being sent to the server and `config` is the config that was passed to |vim.lsp.start_client()|.
+--- being sent to the server and `config` is the config that was passed to |vim.lsp.start()|.
 --- You can use this to modify parameters before they are sent.
 --- @field before_init? fun(params: lsp.InitializeParams, config: vim.lsp.ClientConfig)
 ---
@@ -148,8 +149,10 @@ local validate = vim.validate
 --- See |vim.lsp.rpc.start()|.
 --- @field rpc vim.lsp.rpc.PublicClient
 ---
---- The encoding used for communicating with the server. You can modify this in
---- the `config`'s `on_init` method before text is sent to the server.
+--- Called "position encoding" in LSP spec,
+--- the encoding used for communicating with the server.
+--- You can modify this in the `config`'s `on_init` method
+--- before text is sent to the server.
 --- @field offset_encoding string
 ---
 --- The handlers used by the client as described in |lsp-handler|.
@@ -161,16 +164,20 @@ local validate = vim.validate
 --- for an active request, or "cancel" for a cancel request. It will be
 --- "complete" ephemerally while executing |LspRequest| autocmds when replies
 --- are received from the server.
---- @field requests table<integer,{ type: string, bufnr: integer, method: string}>
+--- @field requests table<integer,{ type: string, bufnr: integer, method: string}?>
 ---
 --- copy of the table that was passed by the user
---- to |vim.lsp.start_client()|.
+--- to |vim.lsp.start()|.
 --- @field config vim.lsp.ClientConfig
 ---
 --- Response from the server sent on `initialize` describing the server's
 --- capabilities.
 --- @field server_capabilities lsp.ServerCapabilities?
 ---
+--- Response from the server sent on `initialize` describing information about
+--- the server.
+--- @field server_info lsp.ServerInfo?
+---
 --- A ring buffer (|vim.ringbuf()|) containing progress messages
 --- sent by the server.
 --- @field progress vim.lsp.Client.Progress
@@ -186,9 +193,6 @@ local validate = vim.validate
 ---
 --- @field attached_buffers table<integer,true>
 ---
---- Buffers that should be attached to upon initialize()
---- @field package _buffers_to_attach table<integer,true>
----
 --- @field private _log_prefix string
 ---
 --- Track this so that we can escalate automatically if we've already tried a
@@ -207,7 +211,7 @@ local validate = vim.validate
 --- Map with language server specific settings. These are returned to the
 --- language server if requested via `workspace/configuration`. Keys are
 --- case-sensitive.
---- @field settings table
+--- @field settings lsp.LSPObject
 ---
 --- A table with flags for the client. The current (experimental) flags are:
 --- @field flags vim.lsp.Client.Flags
@@ -219,70 +223,28 @@ local validate = vim.validate
 --- @field private registrations table<string,lsp.Registration[]>
 --- @field dynamic_capabilities lsp.DynamicCapabilities
 ---
---- Sends a request to the server.
---- This is a thin wrapper around {client.rpc.request} with some additional
---- checking.
---- If {handler} is not specified and if there's no respective global
---- handler, then an error will occur.
---- Returns: {status}, {client_id}?. {status} is a boolean indicating if
---- the notification was successful. If it is `false`, then it will always
---- be `false` (the client has shutdown).
---- If {status} is `true`, the function returns {request_id} as the second
---- result. You can use this with `client.cancel_request(request_id)` to cancel
---- the request.
---- @field request fun(method: string, params: table?, handler: lsp.Handler?, bufnr: integer?): boolean, integer?
----
---- Sends a request to the server and synchronously waits for the response.
---- This is a wrapper around {client.request}
---- Returns: { err=err, result=result }, a dict, where `err` and `result`
---- come from the |lsp-handler|. On timeout, cancel or error, returns `(nil,
---- err)` where `err` is a string describing the failure reason. If the request
---- was unsuccessful returns `nil`.
---- @field request_sync fun(method: string, params: table?, timeout_ms: integer?, bufnr: integer): {err: lsp.ResponseError|nil, result:any}|nil, string|nil err # a dict
----
---- Sends a notification to an LSP server.
---- Returns: a boolean to indicate if the notification was successful. If
---- it is false, then it will always be false (the client has shutdown).
---- @field notify fun(method: string, params: table?): boolean
----
---- Cancels a request with a given request id.
---- Returns: same as `notify()`.
---- @field cancel_request fun(id: integer): boolean
----
---- Stops a client, optionally with force.
---- By default, it will just ask the server to shutdown without force.
---- If you request to stop a client which has previously been requested to
---- shutdown, it will automatically escalate and force shutdown.
---- @field stop fun(force?: boolean)
----
---- Runs the on_attach function from the client's config if it was defined.
---- Useful for buffer-local setup.
---- @field on_attach fun(bufnr: integer)
----
 --- @field private _before_init_cb? vim.lsp.client.before_init_cb
 --- @field private _on_attach_cbs vim.lsp.client.on_attach_cb[]
 --- @field private _on_init_cbs vim.lsp.client.on_init_cb[]
 --- @field private _on_exit_cbs vim.lsp.client.on_exit_cb[]
 --- @field private _on_error_cb? fun(code: integer, err: string)
----
---- Checks if a client supports a given method.
---- Always returns true for unknown off-spec methods.
---- {opts} is a optional `{bufnr?: integer}` table.
---- Some language server capabilities can be file specific.
---- @field supports_method fun(method: string, opts?: {bufnr: integer?}): boolean
----
---- Checks whether a client is stopped.
---- Returns: true if the client is fully stopped.
---- @field is_stopped fun(): boolean
 local Client = {}
 Client.__index = Client
 
---- @param cls table
---- @param meth any
---- @return function
-local function method_wrapper(cls, meth)
-  return function(...)
-    return meth(cls, ...)
+--- @param obj table<string,any>
+--- @param cls table<string,function>
+--- @param name string
+local function method_wrapper(obj, cls, name)
+  local meth = assert(cls[name])
+  obj[name] = function(...)
+    local arg = select(1, ...)
+    if arg and getmetatable(arg) == cls then
+      -- First argument is self, call meth directly
+      return meth(...)
+    end
+    vim.deprecate('client.' .. name, 'client:' .. name, '0.13')
+    -- First argument is not self, insert it
+    return meth(obj, ...)
   end
 end
 
@@ -304,9 +266,6 @@ local valid_encodings = {
   ['utf8'] = 'utf-8',
   ['utf16'] = 'utf-16',
   ['utf32'] = 'utf-32',
-  UTF8 = 'utf-8',
-  UTF16 = 'utf-16',
-  UTF32 = 'utf-32',
 }
 
 --- Normalizes {encoding} to valid LSP encoding names.
@@ -315,12 +274,12 @@ local valid_encodings = {
 local function validate_encoding(encoding)
   validate('encoding', encoding, 'string', true)
   if not encoding then
-    return valid_encodings.UTF16
+    return valid_encodings.utf16
   end
   return valid_encodings[encoding:lower()]
     or error(
       string.format(
-        "Invalid offset encoding %q. Must be one of: 'utf-8', 'utf-16', 'utf-32'",
+        "Invalid position encoding %q. Must be one of: 'utf-8', 'utf-16', 'utf-32'",
         encoding
       )
     )
@@ -346,7 +305,7 @@ local function default_get_language_id(_bufnr, filetype)
   return filetype
 end
 
---- Validates a client configuration as given to |vim.lsp.start_client()|.
+--- Validates a client configuration as given to |vim.lsp.start()|.
 --- @param config vim.lsp.ClientConfig
 local function validate_config(config)
   validate('config', config, 'table')
@@ -404,31 +363,6 @@ local function get_name(id, config)
   return tostring(id)
 end
 
---- @param workspace_folders string|lsp.WorkspaceFolder[]?
---- @return lsp.WorkspaceFolder[]?
-local function get_workspace_folders(workspace_folders)
-  if type(workspace_folders) == 'table' then
-    return workspace_folders
-  elseif type(workspace_folders) == 'string' then
-    return {
-      {
-        uri = vim.uri_from_fname(workspace_folders),
-        name = workspace_folders,
-      },
-    }
-  end
-end
-
---- @generic T
---- @param x elem_or_list<T>?
---- @return T[]
-local function ensure_list(x)
-  if type(x) == 'table' then
-    return x
-  end
-  return { x }
-end
-
 --- @nodoc
 --- @param config vim.lsp.ClientConfig
 --- @return vim.lsp.Client?
@@ -455,13 +389,13 @@ function Client.create(config)
     settings = config.settings or {},
     flags = config.flags or {},
     get_language_id = config.get_language_id or default_get_language_id,
-    capabilities = config.capabilities or lsp.protocol.make_client_capabilities(),
-    workspace_folders = get_workspace_folders(config.workspace_folders or config.root_dir),
+    capabilities = config.capabilities,
+    workspace_folders = lsp._get_workspace_folders(config.workspace_folders or config.root_dir),
     root_dir = config.root_dir,
     _before_init_cb = config.before_init,
-    _on_init_cbs = ensure_list(config.on_init),
-    _on_exit_cbs = ensure_list(config.on_exit),
-    _on_attach_cbs = ensure_list(config.on_attach),
+    _on_init_cbs = vim._ensure_list(config.on_init),
+    _on_exit_cbs = vim._ensure_list(config.on_exit),
+    _on_attach_cbs = vim._ensure_list(config.on_attach),
     _on_error_cb = config.on_error,
     _trace = get_trace(config.trace),
 
@@ -477,6 +411,9 @@ function Client.create(config)
     messages = { name = name, messages = {}, progress = {}, status = {} },
   }
 
+  self.capabilities =
+    vim.tbl_deep_extend('force', lsp.protocol.make_client_capabilities(), self.capabilities or {})
+
   --- @class lsp.DynamicCapabilities
   --- @nodoc
   self.dynamic_capabilities = {
@@ -499,24 +436,23 @@ function Client.create(config)
     end,
   }
 
-  self.request = method_wrapper(self, Client._request)
-  self.request_sync = method_wrapper(self, Client._request_sync)
-  self.notify = method_wrapper(self, Client._notify)
-  self.cancel_request = method_wrapper(self, Client._cancel_request)
-  self.stop = method_wrapper(self, Client._stop)
-  self.is_stopped = method_wrapper(self, Client._is_stopped)
-  self.on_attach = method_wrapper(self, Client._on_attach)
-  self.supports_method = method_wrapper(self, Client._supports_method)
-
   --- @type table<string|integer, string> title of unfinished progress sequences by token
   self.progress.pending = {}
 
   --- @type vim.lsp.rpc.Dispatchers
   local dispatchers = {
-    notification = method_wrapper(self, Client._notification),
-    server_request = method_wrapper(self, Client._server_request),
-    on_error = method_wrapper(self, Client._on_error),
-    on_exit = method_wrapper(self, Client._on_exit),
+    notification = function(...)
+      return self:_notification(...)
+    end,
+    server_request = function(...)
+      return self:_server_request(...)
+    end,
+    on_error = function(...)
+      return self:_on_error(...)
+    end,
+    on_exit = function(...)
+      return self:_on_exit(...)
+    end,
   }
 
   -- Start the RPC client.
@@ -533,6 +469,15 @@ function Client.create(config)
 
   setmetatable(self, Client)
 
+  method_wrapper(self, Client, 'request')
+  method_wrapper(self, Client, 'request_sync')
+  method_wrapper(self, Client, 'notify')
+  method_wrapper(self, Client, 'cancel_request')
+  method_wrapper(self, Client, 'stop')
+  method_wrapper(self, Client, 'is_stopped')
+  method_wrapper(self, Client, 'on_attach')
+  method_wrapper(self, Client, 'supports_method')
+
   return self
 end
 
@@ -615,8 +560,10 @@ function Client:initialize()
       self.offset_encoding = self.server_capabilities.positionEncoding
     end
 
+    self.server_info = result.serverInfo
+
     if next(self.settings) then
-      self:_notify(ms.workspace_didChangeConfiguration, { settings = self.settings })
+      self:notify(ms.workspace_didChangeConfiguration, { settings = self.settings })
     end
 
     -- If server is being restarted, make sure to re-attach to any previously attached buffers.
@@ -628,7 +575,7 @@ function Client:initialize()
     for buf in pairs(reattach_bufs) do
       -- The buffer may have been detached in the on_init callback.
       if self.attached_buffers[buf] then
-        self:_on_attach(buf)
+        self:on_attach(buf)
       end
     end
 
@@ -645,24 +592,62 @@ end
 --- Returns the default handler if the user hasn't set a custom one.
 ---
 --- @param method (string) LSP method name
---- @return lsp.Handler|nil handler for the given method, if defined, or the default from |vim.lsp.handlers|
+--- @return lsp.Handler? handler for the given method, if defined, or the default from |vim.lsp.handlers|
 function Client:_resolve_handler(method)
   return self.handlers[method] or lsp.handlers[method]
 end
 
---- Returns the buffer number for the given {bufnr}.
----
---- @param bufnr (integer|nil) Buffer number to resolve. Defaults to current buffer
---- @return integer bufnr
-local function resolve_bufnr(bufnr)
-  validate('bufnr', bufnr, 'number', true)
-  if bufnr == nil or bufnr == 0 then
-    return api.nvim_get_current_buf()
+--- @private
+--- @param id integer
+--- @param req_type 'pending'|'complete'|'cancel'|
+--- @param bufnr? integer (only required for req_type='pending')
+--- @param method? string (only required for req_type='pending')
+function Client:_process_request(id, req_type, bufnr, method)
+  local pending = req_type == 'pending'
+
+  validate('id', id, 'number')
+  if pending then
+    validate('bufnr', bufnr, 'number')
+    validate('method', method, 'string')
+  end
+
+  local cur_request = self.requests[id]
+
+  if pending and cur_request then
+    log.error(
+      self._log_prefix,
+      ('Cannot create request with id %d as one already exists'):format(id)
+    )
+    return
+  elseif not pending and not cur_request then
+    log.error(
+      self._log_prefix,
+      ('Cannot find request with id %d whilst attempting to %s'):format(id, req_type)
+    )
+    return
+  end
+
+  if cur_request then
+    bufnr = cur_request.bufnr
+    method = cur_request.method
   end
-  return bufnr
+
+  assert(bufnr and method)
+
+  local request = { type = req_type, bufnr = bufnr, method = method }
+
+  -- Clear 'complete' requests
+  -- Note 'pending' and 'cancelled' requests are cleared when the server sends a response
+  -- which is processed via the notify_reply_callback argument to rpc.request.
+  self.requests[id] = req_type ~= 'complete' and request or nil
+
+  api.nvim_exec_autocmds('LspRequest', {
+    buffer = api.nvim_buf_is_valid(bufnr) and bufnr or nil,
+    modeline = false,
+    data = { client_id = self.id, request_id = id, request = request },
+  })
 end
 
---- @private
 --- Sends a request to the server.
 ---
 --- This is a thin wrapper around {client.rpc.request} with some additional
@@ -671,15 +656,14 @@ end
 --- @param method string LSP method name.
 --- @param params? table LSP request params.
 --- @param handler? lsp.Handler Response |lsp-handler| for this method.
---- @param bufnr integer Buffer handle (0 for current).
---- @return boolean status, integer? request_id {status} is a bool indicating
---- whether the request was successful. If it is `false`, then it will
---- always be `false` (the client has shutdown). If it was
---- successful, then it will return {request_id} as the
---- second result. You can use this with `client.cancel_request(request_id)`
+--- @param bufnr? integer (default: 0) Buffer handle, or 0 for current.
+--- @return boolean status indicates whether the request was successful.
+---     If it is `false`, then it will always be `false` (the client has shutdown).
+--- @return integer? request_id Can be used with |Client:cancel_request()|.
+---                             `nil` is request failed.
 --- to cancel the-request.
 --- @see |vim.lsp.buf_request_all()|
-function Client:_request(method, params, handler, bufnr)
+function Client:request(method, params, handler, bufnr)
   if not handler then
     handler = assert(
       self:_resolve_handler(method),
@@ -688,37 +672,24 @@ function Client:_request(method, params, handler, bufnr)
   end
   -- Ensure pending didChange notifications are sent so that the server doesn't operate on a stale state
   changetracking.flush(self, bufnr)
+  bufnr = vim._resolve_bufnr(bufnr)
   local version = lsp.util.buf_versions[bufnr]
-  bufnr = resolve_bufnr(bufnr)
   log.debug(self._log_prefix, 'client.request', self.id, method, params, handler, bufnr)
   local success, request_id = self.rpc.request(method, params, function(err, result)
-    local context = {
+    handler(err, result, {
       method = method,
       client_id = self.id,
       bufnr = bufnr,
       params = params,
       version = version,
-    }
-    handler(err, result, context)
-  end, function(request_id)
-    local request = self.requests[request_id]
-    request.type = 'complete'
-    api.nvim_exec_autocmds('LspRequest', {
-      buffer = api.nvim_buf_is_valid(bufnr) and bufnr or nil,
-      modeline = false,
-      data = { client_id = self.id, request_id = request_id, request = request },
     })
-    self.requests[request_id] = nil
+  end, function(request_id)
+    -- Called when the server sends a response to the request (including cancelled acknowledgment).
+    self:_process_request(request_id, 'complete')
   end)
 
   if success and request_id then
-    local request = { type = 'pending', bufnr = bufnr, method = method }
-    self.requests[request_id] = request
-    api.nvim_exec_autocmds('LspRequest', {
-      buffer = api.nvim_buf_is_valid(bufnr) and bufnr or nil,
-      modeline = false,
-      data = { client_id = self.id, request_id = request_id, request = request },
-    })
+    self:_process_request(request_id, 'pending', bufnr, method)
   end
 
   return success, request_id
@@ -731,41 +702,39 @@ local wait_result_reason = { [-1] = 'timeout', [-2] = 'interrupted', [-3] = 'err
 ---
 --- @param ... string List to write to the buffer
 local function err_message(...)
-  local message = table.concat(vim.iter({ ... }):flatten():totable())
+  local chunks = { { table.concat(vim.iter({ ... }):flatten():totable()) } }
   if vim.in_fast_event() then
     vim.schedule(function()
-      api.nvim_err_writeln(message)
+      api.nvim_echo(chunks, true, { err = true })
       api.nvim_command('redraw')
     end)
   else
-    api.nvim_err_writeln(message)
+    api.nvim_echo(chunks, true, { err = true })
     api.nvim_command('redraw')
   end
 end
 
---- @private
 --- Sends a request to the server and synchronously waits for the response.
 ---
---- This is a wrapper around {client.request}
+--- This is a wrapper around |Client:request()|
 ---
---- @param method (string) LSP method name.
---- @param params (table) LSP request params.
---- @param timeout_ms (integer|nil) Maximum time in milliseconds to wait for
+--- @param method string LSP method name.
+--- @param params table LSP request params.
+--- @param timeout_ms integer? Maximum time in milliseconds to wait for
 ---                                a result. Defaults to 1000
---- @param bufnr (integer) Buffer handle (0 for current).
---- @return {err: lsp.ResponseError|nil, result:any}|nil, string|nil err # a dict, where
---- `err` and `result` come from the |lsp-handler|.
---- On timeout, cancel or error, returns `(nil, err)` where `err` is a
---- string describing the failure reason. If the request was unsuccessful
---- returns `nil`.
+--- @param bufnr? integer (default: 0) Buffer handle, or 0 for current.
+--- @return {err: lsp.ResponseError?, result:any}? `result` and `err` from the |lsp-handler|.
+---                 `nil` is the request was unsuccessful
+--- @return string? err On timeout, cancel or error, where `err` is a
+---                 string describing the failure reason.
 --- @see |vim.lsp.buf_request_sync()|
-function Client:_request_sync(method, params, timeout_ms, bufnr)
+function Client:request_sync(method, params, timeout_ms, bufnr)
   local request_result = nil
   local function _sync_handler(err, result)
     request_result = { err = err, result = result }
   end
 
-  local success, request_id = self:_request(method, params, _sync_handler, bufnr)
+  local success, request_id = self:request(method, params, _sync_handler, bufnr)
   if not success then
     return nil
   end
@@ -776,22 +745,20 @@ function Client:_request_sync(method, params, timeout_ms, bufnr)
 
   if not wait_result then
     if request_id then
-      self:_cancel_request(request_id)
+      self:cancel_request(request_id)
     end
     return nil, wait_result_reason[reason]
   end
   return request_result
 end
 
---- @package
 --- Sends a notification to an LSP server.
 ---
 --- @param method string LSP method name.
---- @param params table|nil LSP request params.
---- @return boolean status true if the notification was successful.
---- If it is false, then it will always be false
---- (the client has shutdown).
-function Client:_notify(method, params)
+--- @param params table? LSP request params.
+--- @return boolean status indicating if the notification was successful.
+---                        If it is false, then the client has shutdown.
+function Client:notify(method, params)
   if method ~= ms.textDocument_didChange then
     changetracking.flush(self)
   end
@@ -814,41 +781,32 @@ function Client:_notify(method, params)
   return client_active
 end
 
---- @private
 --- Cancels a request with a given request id.
 ---
---- @param id (integer) id of request to cancel
---- @return boolean status true if notification was successful. false otherwise
---- @see |vim.lsp.client.notify()|
-function Client:_cancel_request(id)
-  validate('id', id, 'number')
-  local request = self.requests[id]
-  if request and request.type == 'pending' then
-    request.type = 'cancel'
-    api.nvim_exec_autocmds('LspRequest', {
-      buffer = api.nvim_buf_is_valid(request.bufnr) and request.bufnr or nil,
-      modeline = false,
-      data = { client_id = self.id, request_id = id, request = request },
-    })
-  end
+--- @param id integer id of request to cancel
+--- @return boolean status indicating if the notification was successful.
+--- @see |Client:notify()|
+function Client:cancel_request(id)
+  self:_process_request(id, 'cancel')
   return self.rpc.notify(ms.dollar_cancelRequest, { id = id })
 end
 
---- @private
 --- Stops a client, optionally with force.
 ---
---- By default, it will just ask the - server to shutdown without force. If
+--- By default, it will just request the server to shutdown without force. If
 --- you request to stop a client which has previously been requested to
 --- shutdown, it will automatically escalate and force shutdown.
 ---
---- @param force boolean|nil
-function Client:_stop(force)
+--- @param force? boolean
+function Client:stop(force)
   local rpc = self.rpc
 
   if rpc.is_closing() then
     return
   end
 
+  vim.lsp._watchfiles.cancel(self.id)
+
   if force or not self.initialized or self._graceful_shutdown_failed then
     rpc.terminate()
     return
@@ -863,7 +821,6 @@ function Client:_stop(force)
       rpc.terminate()
       self._graceful_shutdown_failed = true
     end
-    vim.lsp._watchfiles.cancel(self.id)
   end)
 end
 
@@ -945,20 +902,22 @@ end
 --- @param bufnr? integer
 --- @return lsp.Registration?
 function Client:_get_registration(method, bufnr)
-  bufnr = bufnr or vim.api.nvim_get_current_buf()
+  bufnr = vim._resolve_bufnr(bufnr)
   for _, reg in ipairs(self.registrations[method] or {}) do
-    if not reg.registerOptions or not reg.registerOptions.documentSelector then
+    local regoptions = reg.registerOptions --[[@as {documentSelector:lsp.TextDocumentFilter[]}]]
+    if not regoptions or not regoptions.documentSelector then
       return reg
     end
-    local documentSelector = reg.registerOptions.documentSelector
+    local documentSelector = regoptions.documentSelector
     local language = self:_get_language_id(bufnr)
     local uri = vim.uri_from_bufnr(bufnr)
     local fname = vim.uri_to_fname(uri)
     for _, filter in ipairs(documentSelector) do
+      local flang, fscheme, fpat = filter.language, filter.scheme, filter.pattern
       if
-        not (filter.language and language ~= filter.language)
-        and not (filter.scheme and not vim.startswith(uri, filter.scheme .. ':'))
-        and not (filter.pattern and not vim.glob.to_lpeg(filter.pattern):match(fname))
+        not (flang and language ~= flang)
+        and not (fscheme and not vim.startswith(uri, fscheme .. ':'))
+        and not (type(fpat) == 'string' and not vim.glob.to_lpeg(fpat):match(fname))
       then
         return reg
       end
@@ -966,12 +925,11 @@ function Client:_get_registration(method, bufnr)
   end
 end
 
---- @private
 --- Checks whether a client is stopped.
 ---
 --- @return boolean # true if client is stopped or in the process of being
 --- stopped; false otherwise
-function Client:_is_stopped()
+function Client:is_stopped()
   return self.rpc.is_closing()
 end
 
@@ -983,7 +941,7 @@ end
 --- @param handler? lsp.Handler only called if a server command
 function Client:exec_cmd(command, context, handler)
   context = vim.deepcopy(context or {}, true) --[[@as lsp.HandlerContext]]
-  context.bufnr = context.bufnr or api.nvim_get_current_buf()
+  context.bufnr = vim._resolve_bufnr(context.bufnr)
   context.client_id = self.id
   local cmdname = command.command
   local fn = self.commands[cmdname] or lsp.commands[cmdname]
@@ -1013,7 +971,7 @@ function Client:exec_cmd(command, context, handler)
     command = cmdname,
     arguments = command.arguments,
   }
-  self.request(ms.workspace_executeCommand, params, handler, context.bufnr)
+  self:request(ms.workspace_executeCommand, params, handler, context.bufnr)
 end
 
 --- Default handler for the 'textDocument/didOpen' LSP notification.
@@ -1021,14 +979,14 @@ end
 --- @param bufnr integer Number of the buffer, or 0 for current
 function Client:_text_document_did_open_handler(bufnr)
   changetracking.init(self, bufnr)
-  if not self.supports_method(ms.textDocument_didOpen) then
+  if not self:supports_method(ms.textDocument_didOpen) then
     return
   end
   if not api.nvim_buf_is_loaded(bufnr) then
     return
   end
 
-  self.notify(ms.textDocument_didOpen, {
+  self:notify(ms.textDocument_didOpen, {
     textDocument = {
       version = lsp.util.buf_versions[bufnr],
       uri = vim.uri_from_bufnr(bufnr),
@@ -1049,8 +1007,9 @@ function Client:_text_document_did_open_handler(bufnr)
 end
 
 --- Runs the on_attach function from the client's config if it was defined.
+--- Useful for buffer-local setup.
 --- @param bufnr integer Buffer number
-function Client:_on_attach(bufnr)
+function Client:on_attach(bufnr)
   self:_text_document_did_open_handler(bufnr)
 
   lsp._set_defaults(self, bufnr)
@@ -1085,10 +1044,18 @@ function Client:write_error(code, err)
   err_message(self._log_prefix, ': Error ', client_error, ': ', vim.inspect(err))
 end
 
---- @private
+--- Checks if a client supports a given method.
+--- Always returns true for unknown off-spec methods.
+---
+--- Note: Some language server capabilities can be file specific.
 --- @param method string
---- @param opts? {bufnr: integer?}
-function Client:_supports_method(method, opts)
+--- @param bufnr? integer
+function Client:supports_method(method, bufnr)
+  -- Deprecated form
+  if type(bufnr) == 'table' then
+    --- @diagnostic disable-next-line:no-unknown
+    bufnr = bufnr.bufnr
+  end
   local required_capability = lsp._request_name_to_capability[method]
   -- if we don't know about the method, assume that the client supports it.
   if not required_capability then
@@ -1101,12 +1068,12 @@ function Client:_supports_method(method, opts)
   local rmethod = lsp._resolve_to_request[method]
   if rmethod then
     if self:_supports_registration(rmethod) then
-      local reg = self:_get_registration(rmethod, opts and opts.bufnr)
+      local reg = self:_get_registration(rmethod, bufnr)
       return vim.tbl_get(reg or {}, 'registerOptions', 'resolveProvider') or false
     end
   else
     if self:_supports_registration(method) then
-      return self:_get_registration(method, opts and opts.bufnr) ~= nil
+      return self:_get_registration(method, bufnr) ~= nil
     end
   end
   return false
@@ -1205,9 +1172,9 @@ function Client:_add_workspace_folder(dir)
     end
   end
 
-  local wf = assert(get_workspace_folders(dir))
+  local wf = assert(lsp._get_workspace_folders(dir))
 
-  self:_notify(ms.workspace_didChangeWorkspaceFolders, {
+  self:notify(ms.workspace_didChangeWorkspaceFolders, {
     event = { added = wf, removed = {} },
   })
 
@@ -1220,9 +1187,9 @@ end
 --- Remove a directory to the workspace folders.
 --- @param dir string?
 function Client:_remove_workspace_folder(dir)
-  local wf = assert(get_workspace_folders(dir))
+  local wf = assert(lsp._get_workspace_folders(dir))
 
-  self:_notify(ms.workspace_didChangeWorkspaceFolders, {
+  self:notify(ms.workspace_didChangeWorkspaceFolders, {
     event = { added = {}, removed = wf },
   })
 
diff --git a/runtime/lua/vim/lsp/codelens.lua b/runtime/lua/vim/lsp/codelens.lua
index fdbdda695a..e36d8fee27 100644
--- a/runtime/lua/vim/lsp/codelens.lua
+++ b/runtime/lua/vim/lsp/codelens.lua
@@ -21,7 +21,7 @@ local lens_cache_by_buf = setmetatable({}, {
 ---client_id -> namespace
 local namespaces = setmetatable({}, {
   __index = function(t, key)
-    local value = api.nvim_create_namespace('vim_lsp_codelens:' .. key)
+    local value = api.nvim_create_namespace('nvim.lsp.codelens:' .. key)
     rawset(t, key, value)
     return value
   end,
@@ -30,7 +30,7 @@ local namespaces = setmetatable({}, {
 ---@private
 M.__namespaces = namespaces
 
-local augroup = api.nvim_create_augroup('vim_lsp_codelens', {})
+local augroup = api.nvim_create_augroup('nvim.lsp.codelens', {})
 
 api.nvim_create_autocmd('LspDetach', {
   group = augroup,
@@ -104,16 +104,12 @@ function M.run()
   end
 end
 
-local function resolve_bufnr(bufnr)
-  return bufnr == 0 and api.nvim_get_current_buf() or bufnr
-end
-
 --- Clear the lenses
 ---
 ---@param client_id integer|nil filter by client_id. All clients if nil
 ---@param bufnr integer|nil filter by buffer. All buffers if nil, 0 for current buffer
 function M.clear(client_id, bufnr)
-  bufnr = bufnr and resolve_bufnr(bufnr)
+  bufnr = bufnr and vim._resolve_bufnr(bufnr)
   local buffers = bufnr and { bufnr }
     or vim.tbl_filter(api.nvim_buf_is_loaded, api.nvim_list_bufs())
   for _, iter_bufnr in pairs(buffers) do
@@ -231,7 +227,7 @@ local function resolve_lenses(lenses, bufnr, client_id, callback)
       countdown()
     else
       assert(client)
-      client.request(ms.codeLens_resolve, lens, function(_, result)
+      client:request(ms.codeLens_resolve, lens, function(_, result)
         if api.nvim_buf_is_loaded(bufnr) and result and result.command then
           lens.command = result.command
           -- Eager display to have some sort of incremental feedback
@@ -296,7 +292,7 @@ end
 --- @param opts? vim.lsp.codelens.refresh.Opts Optional fields
 function M.refresh(opts)
   opts = opts or {}
-  local bufnr = opts.bufnr and resolve_bufnr(opts.bufnr)
+  local bufnr = opts.bufnr and vim._resolve_bufnr(opts.bufnr)
   local buffers = bufnr and { bufnr }
     or vim.tbl_filter(api.nvim_buf_is_loaded, api.nvim_list_bufs())
 
diff --git a/runtime/lua/vim/lsp/completion.lua b/runtime/lua/vim/lsp/completion.lua
index 92bc110a97..cf6d07745f 100644
--- a/runtime/lua/vim/lsp/completion.lua
+++ b/runtime/lua/vim/lsp/completion.lua
@@ -127,8 +127,10 @@ end
 --- See https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion
 ---
 --- @param item lsp.CompletionItem
+--- @param prefix string
+--- @param match fun(text: string, prefix: string):boolean
 --- @return string
-local function get_completion_word(item)
+local function get_completion_word(item, prefix, match)
   if item.insertTextFormat == protocol.InsertTextFormat.Snippet then
     if item.textEdit then
       -- Use label instead of text if text has different starting characters.
@@ -146,7 +148,12 @@ local function get_completion_word(item)
       --
       -- Typing `i` would remove the candidate because newText starts with `t`.
       local text = parse_snippet(item.insertText or item.textEdit.newText)
-      return #text < #item.label and vim.fn.matchstr(text, '\\k*') or item.label
+      local word = #text < #item.label and vim.fn.matchstr(text, '\\k*') or item.label
+      if item.filterText and not match(word, prefix) then
+        return item.filterText
+      else
+        return word
+      end
     elseif item.insertText and item.insertText ~= '' then
       return parse_snippet(item.insertText)
     else
@@ -224,6 +231,9 @@ end
 ---@param prefix string
 ---@return boolean
 local function match_item_by_value(value, prefix)
+  if prefix == '' then
+    return true
+  end
   if vim.o.completeopt:find('fuzzy') ~= nil then
     return next(vim.fn.matchfuzzy({ value }, prefix)) ~= nil
   end
@@ -276,7 +286,7 @@ function M._lsp_to_complete_items(result, prefix, client_id)
   local user_convert = vim.tbl_get(buf_handles, bufnr, 'convert')
   for _, item in ipairs(items) do
     if matches(item) then
-      local word = get_completion_word(item)
+      local word = get_completion_word(item, prefix, match_item_by_value)
       local hl_group = ''
       if
         item.deprecated
@@ -404,7 +414,7 @@ local function request(clients, bufnr, win, callback)
   for _, client in pairs(clients) do
     local client_id = client.id
     local params = lsp.util.make_position_params(win, client.offset_encoding)
-    local ok, request_id = client.request(ms.textDocument_completion, params, function(err, result)
+    local ok, request_id = client:request(ms.textDocument_completion, params, function(err, result)
       responses[client_id] = { err = err, result = result }
       remaining_requests = remaining_requests - 1
       if remaining_requests == 0 then
@@ -421,7 +431,7 @@ local function request(clients, bufnr, win, callback)
     for client_id, request_id in pairs(request_ids) do
       local client = lsp.get_client_by_id(client_id)
       if client then
-        client.cancel_request(request_id)
+        client:cancel_request(request_id)
       end
     end
   end
@@ -460,7 +470,7 @@ local function trigger(bufnr, clients)
     local server_start_boundary --- @type integer?
     for client_id, response in pairs(responses) do
       if response.err then
-        vim.notify_once(response.err.message, vim.log.levels.warn)
+        vim.notify_once(response.err.message, vim.log.levels.WARN)
       end
 
       local result = response.result
@@ -550,7 +560,7 @@ local function on_complete_done()
     return
   end
 
-  local offset_encoding = client.offset_encoding or 'utf-16'
+  local position_encoding = client.offset_encoding or 'utf-16'
   local resolve_provider = (client.server_capabilities.completionProvider or {}).resolveProvider
 
   local function clear_word()
@@ -576,13 +586,13 @@ local function on_complete_done()
 
   if completion_item.additionalTextEdits and next(completion_item.additionalTextEdits) then
     clear_word()
-    lsp.util.apply_text_edits(completion_item.additionalTextEdits, bufnr, offset_encoding)
+    lsp.util.apply_text_edits(completion_item.additionalTextEdits, bufnr, position_encoding)
     apply_snippet_and_command()
   elseif resolve_provider and type(completion_item) == 'table' then
     local changedtick = vim.b[bufnr].changedtick
 
     --- @param result lsp.CompletionItem
-    client.request(ms.completionItem_resolve, completion_item, function(err, result)
+    client:request(ms.completionItem_resolve, completion_item, function(err, result)
       if changedtick ~= vim.b[bufnr].changedtick then
         return
       end
@@ -591,7 +601,7 @@ local function on_complete_done()
       if err then
         vim.notify_once(err.message, vim.log.levels.WARN)
       elseif result and result.additionalTextEdits then
-        lsp.util.apply_text_edits(result.additionalTextEdits, bufnr, offset_encoding)
+        lsp.util.apply_text_edits(result.additionalTextEdits, bufnr, position_encoding)
         if result.command then
           completion_item.command = result.command
         end
@@ -605,6 +615,12 @@ local function on_complete_done()
   end
 end
 
+---@param bufnr integer
+---@return string
+local function get_augroup(bufnr)
+  return string.format('nvim.lsp.completion_%d', bufnr)
+end
+
 --- @class vim.lsp.completion.BufferOpts
 --- @field autotrigger? boolean  Default: false When true, completion triggers automatically based on the server's `triggerCharacters`.
 --- @field convert? fun(item: lsp.CompletionItem): table Transforms an LSP CompletionItem to |complete-items|.
@@ -629,8 +645,7 @@ local function enable_completions(client_id, bufnr, opts)
     })
 
     -- Set up autocommands.
-    local group =
-      api.nvim_create_augroup(string.format('vim/lsp/completion-%d', bufnr), { clear = true })
+    local group = api.nvim_create_augroup(get_augroup(bufnr), { clear = true })
     api.nvim_create_autocmd('CompleteDone', {
       group = group,
       buffer = bufnr,
@@ -698,7 +713,7 @@ local function disable_completions(client_id, bufnr)
   handle.clients[client_id] = nil
   if not next(handle.clients) then
     buf_handles[bufnr] = nil
-    api.nvim_del_augroup_by_name(string.format('vim/lsp/completion-%d', bufnr))
+    api.nvim_del_augroup_by_name(get_augroup(bufnr))
   else
     for char, clients in pairs(handle.triggers) do
       --- @param c vim.lsp.Client
@@ -716,7 +731,7 @@ end
 --- @param bufnr integer Buffer handle, or 0 for the current buffer
 --- @param opts? vim.lsp.completion.BufferOpts
 function M.enable(enable, client_id, bufnr, opts)
-  bufnr = (bufnr == 0 and api.nvim_get_current_buf()) or bufnr
+  bufnr = vim._resolve_bufnr(bufnr)
 
   if enable then
     enable_completions(client_id, bufnr, opts or {})
diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index 8fd30c7668..fe24928a69 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -5,7 +5,7 @@ local api = vim.api
 
 local M = {}
 
-local augroup = api.nvim_create_augroup('vim_lsp_diagnostic', {})
+local augroup = api.nvim_create_augroup('nvim.lsp.diagnostic', {})
 
 local DEFAULT_CLIENT_ID = -1
 
@@ -20,7 +20,7 @@ end
 ---@return lsp.DiagnosticSeverity
 local function severity_vim_to_lsp(severity)
   if type(severity) == 'string' then
-    severity = vim.diagnostic.severity[severity]
+    severity = vim.diagnostic.severity[severity] --- @type integer
   end
   return severity
 end
@@ -77,7 +77,7 @@ end
 local function diagnostic_lsp_to_vim(diagnostics, bufnr, client_id)
   local buf_lines = get_buf_lines(bufnr)
   local client = vim.lsp.get_client_by_id(client_id)
-  local offset_encoding = client and client.offset_encoding or 'utf-16'
+  local position_encoding = client and client.offset_encoding or 'utf-16'
   --- @param diagnostic lsp.Diagnostic
   --- @return vim.Diagnostic
   return vim.tbl_map(function(diagnostic)
@@ -89,15 +89,16 @@ local function diagnostic_lsp_to_vim(diagnostics, bufnr, client_id)
         string.format('Unsupported Markup message from LSP client %d', client_id),
         vim.lsp.log_levels.ERROR
       )
+      --- @diagnostic disable-next-line: undefined-field,no-unknown
       message = diagnostic.message.value
     end
     local line = buf_lines and buf_lines[start.line + 1] or ''
     --- @type vim.Diagnostic
     return {
       lnum = start.line,
-      col = vim.str_byteindex(line, offset_encoding, start.character, false),
+      col = vim.str_byteindex(line, position_encoding, start.character, false),
       end_lnum = _end.line,
-      end_col = vim.str_byteindex(line, offset_encoding, _end.character, false),
+      end_col = vim.str_byteindex(line, position_encoding, _end.character, false),
       severity = severity_lsp_to_vim(diagnostic.severity),
       message = message,
       source = diagnostic.source,
@@ -208,7 +209,7 @@ end
 
 --- @param uri string
 --- @param client_id? integer
---- @param diagnostics vim.Diagnostic[]
+--- @param diagnostics lsp.Diagnostic[]
 --- @param is_pull boolean
 local function handle_diagnostics(uri, client_id, diagnostics, is_pull)
   local fname = vim.uri_to_fname(uri)
@@ -246,10 +247,18 @@ end
 ---
 --- See |vim.diagnostic.config()| for configuration options.
 ---
----@param _ lsp.ResponseError?
+---@param error lsp.ResponseError?
 ---@param result lsp.DocumentDiagnosticReport
 ---@param ctx lsp.HandlerContext
-function M.on_diagnostic(_, result, ctx)
+function M.on_diagnostic(error, result, ctx)
+  if error ~= nil and error.code == protocol.ErrorCodes.ServerCancelled then
+    if error.data == nil or error.data.retriggerRequest ~= false then
+      local client = assert(vim.lsp.get_client_by_id(ctx.client_id))
+      client:request(ctx.method, ctx.params)
+    end
+    return
+  end
+
   if result == nil or result.kind == 'unchanged' then
     return
   end
@@ -348,9 +357,7 @@ end
 ---@param bufnr (integer) Buffer handle, or 0 for current
 ---@private
 function M._enable(bufnr)
-  if bufnr == nil or bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
 
   if not bufstates[bufnr] then
     bufstates[bufnr] = { enabled = true }
diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index 5c28d88b38..b35140dfad 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -47,7 +47,7 @@ RSC[ms.dollar_progress] = function(_, params, ctx)
   local value = params.value
 
   if type(value) == 'table' then
-    kind = value.kind
+    kind = value.kind --- @type string
     -- Carry over title of `begin` messages to `report` and `end` messages
     -- So that consumers always have it available, even if they consume a
     -- subset of the full sequence
@@ -247,12 +247,12 @@ local function response_to_list(map_result, entity, title_fn)
     local items = map_result(result, ctx.bufnr)
 
     local list = { title = title, items = items, context = ctx }
-    if config.loclist then
-      vim.fn.setloclist(0, {}, ' ', list)
-      vim.cmd.lopen()
-    elseif config.on_list then
+    if config.on_list then
       assert(vim.is_callable(config.on_list), 'on_list is not a function')
       config.on_list(list)
+    elseif config.loclist then
+      vim.fn.setloclist(0, {}, ' ', list)
+      vim.cmd.lopen()
     else
       vim.fn.setqflist({}, ' ', list)
       vim.cmd('botright copen')
@@ -382,7 +382,7 @@ end
 --- @diagnostic disable-next-line: deprecated
 RCS[ms.textDocument_hover] = M.hover
 
-local sig_help_ns = api.nvim_create_namespace('vim_lsp_signature_help')
+local sig_help_ns = api.nvim_create_namespace('nvim.lsp.signature_help')
 
 --- @deprecated remove in 0.13
 --- |lsp-handler| for the method "textDocument/signatureHelp".
@@ -582,9 +582,8 @@ NSC['window/showMessage'] = function(_, params, ctx)
   if message_type == protocol.MessageType.Error then
     err_message('LSP[', client_name, '] ', message)
   else
-    --- @type string
-    local message_type_name = protocol.MessageType[message_type]
-    api.nvim_out_write(string.format('LSP[%s][%s] %s\n', client_name, message_type_name, message))
+    message = ('LSP[%s][%s] %s\n'):format(client_name, protocol.MessageType[message_type], message)
+    api.nvim_echo({ { message } }, true, {})
   end
   return params
 end
@@ -659,7 +658,8 @@ for k, fn in pairs(M) do
       })
     end
 
-    if err then
+    -- ServerCancelled errors should be propagated to the request handler
+    if err and err.code ~= protocol.ErrorCodes.ServerCancelled then
       -- LSP spec:
       -- interface ResponseError:
       --  code: integer;
diff --git a/runtime/lua/vim/lsp/health.lua b/runtime/lua/vim/lsp/health.lua
index 0d314108fe..8af9f2f791 100644
--- a/runtime/lua/vim/lsp/health.lua
+++ b/runtime/lua/vim/lsp/health.lua
@@ -28,42 +28,48 @@ local function check_log()
   report_fn(string.format('Log size: %d KB', log_size / 1000))
 end
 
+--- @param f function
+--- @return string
+local function func_tostring(f)
+  local info = debug.getinfo(f, 'S')
+  return ('<function %s:%s>'):format(info.source, info.linedefined)
+end
+
 local function check_active_clients()
   vim.health.start('vim.lsp: Active Clients')
   local clients = vim.lsp.get_clients()
   if next(clients) then
     for _, client in pairs(clients) do
+      local server_version = vim.tbl_get(client, 'server_info', 'version')
+        or '? (no serverInfo.version response)'
       local cmd ---@type string
-      if type(client.config.cmd) == 'table' then
-        cmd = table.concat(client.config.cmd --[[@as table]], ' ')
-      elseif type(client.config.cmd) == 'function' then
-        cmd = tostring(client.config.cmd)
+      local ccmd = client.config.cmd
+      if type(ccmd) == 'table' then
+        cmd = vim.inspect(ccmd)
+      elseif type(ccmd) == 'function' then
+        cmd = func_tostring(ccmd)
       end
       local dirs_info ---@type string
       if client.workspace_folders and #client.workspace_folders > 1 then
-        dirs_info = string.format(
-          '  Workspace folders:\n    %s',
-          vim
-            .iter(client.workspace_folders)
-            ---@param folder lsp.WorkspaceFolder
-            :map(function(folder)
-              return folder.name
-            end)
-            :join('\n    ')
-        )
+        local wfolders = {} --- @type string[]
+        for _, dir in ipairs(client.workspace_folders) do
+          wfolders[#wfolders + 1] = dir.name
+        end
+        dirs_info = ('- Workspace folders:\n    %s'):format(table.concat(wfolders, '\n    '))
       else
         dirs_info = string.format(
-          '  Root directory: %s',
+          '- Root directory: %s',
           client.root_dir and vim.fn.fnamemodify(client.root_dir, ':~')
         ) or nil
       end
       report_info(table.concat({
         string.format('%s (id: %d)', client.name, client.id),
+        string.format('- Version: %s', server_version),
         dirs_info,
-        string.format('  Command: %s', cmd),
-        string.format('  Settings: %s', vim.inspect(client.settings, { newline = '\n  ' })),
+        string.format('- Command: %s', cmd),
+        string.format('- Settings: %s', vim.inspect(client.settings, { newline = '\n  ' })),
         string.format(
-          '  Attached buffers: %s',
+          '- Attached buffers: %s',
           vim.iter(pairs(client.attached_buffers)):map(tostring):join(', ')
         ),
       }, '\n'))
@@ -174,10 +180,45 @@ local function check_position_encodings()
   end
 end
 
+local function check_enabled_configs()
+  vim.health.start('vim.lsp: Enabled Configurations')
+
+  for name in vim.spairs(vim.lsp._enabled_configs) do
+    local config = vim.lsp.config[name]
+    local text = {} --- @type string[]
+    text[#text + 1] = ('%s:'):format(name)
+    for k, v in
+      vim.spairs(config --[[@as table<string,any>]])
+    do
+      local v_str --- @type string?
+      if k == 'name' then
+        v_str = nil
+      elseif k == 'filetypes' or k == 'root_markers' then
+        v_str = table.concat(v, ', ')
+      elseif type(v) == 'function' then
+        v_str = func_tostring(v)
+      else
+        v_str = vim.inspect(v, { newline = '\n  ' })
+      end
+
+      if k == 'cmd' and type(v) == 'table' and vim.fn.executable(v[1]) == 0 then
+        report_warn(("'%s' is not executable. Configuration will not be used."):format(v[1]))
+      end
+
+      if v_str then
+        text[#text + 1] = ('- %s: %s'):format(k, v_str)
+      end
+    end
+    text[#text + 1] = ''
+    report_info(table.concat(text, '\n'))
+  end
+end
+
 --- Performs a healthcheck for LSP
 function M.check()
   check_log()
   check_active_clients()
+  check_enabled_configs()
   check_watcher()
   check_position_encodings()
 end
diff --git a/runtime/lua/vim/lsp/inlay_hint.lua b/runtime/lua/vim/lsp/inlay_hint.lua
index f1ae9a8e9e..37e1202d1d 100644
--- a/runtime/lua/vim/lsp/inlay_hint.lua
+++ b/runtime/lua/vim/lsp/inlay_hint.lua
@@ -29,8 +29,8 @@ local bufstates = vim.defaulttable(function(_)
   })
 end)
 
-local namespace = api.nvim_create_namespace('vim_lsp_inlayhint')
-local augroup = api.nvim_create_augroup('vim_lsp_inlayhint', {})
+local namespace = api.nvim_create_namespace('nvim.lsp.inlayhint')
+local augroup = api.nvim_create_augroup('nvim.lsp.inlayhint', {})
 
 --- |lsp-handler| for the method `textDocument/inlayHint`
 --- Store hints for a specific buffer and client
@@ -122,12 +122,12 @@ end
 --- local hint = vim.lsp.inlay_hint.get({ bufnr = 0 })[1] -- 0 for current buffer
 ---
 --- local client = vim.lsp.get_client_by_id(hint.client_id)
---- local resp = client.request_sync('inlayHint/resolve', hint.inlay_hint, 100, 0)
+--- local resp = client:request_sync('inlayHint/resolve', hint.inlay_hint, 100, 0)
 --- local resolved_hint = assert(resp and resp.result, resp.err)
 --- vim.lsp.util.apply_text_edits(resolved_hint.textEdits, 0, client.encoding)
 ---
 --- location = resolved_hint.label[1].location
---- client.request('textDocument/hover', {
+--- client:request('textDocument/hover', {
 ---   textDocument = { uri = location.uri },
 ---   position = location.range.start,
 --- })
@@ -149,8 +149,8 @@ function M.get(filter)
       vim.list_extend(hints, M.get(vim.tbl_extend('keep', { bufnr = buf }, filter)))
     end, vim.api.nvim_list_bufs())
     return hints
-  elseif bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
+  else
+    bufnr = vim._resolve_bufnr(bufnr)
   end
 
   local bufstate = bufstates[bufnr]
@@ -203,9 +203,7 @@ end
 --- Clear inlay hints
 ---@param bufnr (integer) Buffer handle, or 0 for current
 local function clear(bufnr)
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
   local bufstate = bufstates[bufnr]
   local client_lens = (bufstate or {}).client_hints or {}
   local client_ids = vim.tbl_keys(client_lens) --- @type integer[]
@@ -221,9 +219,7 @@ end
 --- Disable inlay hints for a buffer
 ---@param bufnr (integer) Buffer handle, or 0 for current
 local function _disable(bufnr)
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
   clear(bufnr)
   bufstates[bufnr] = nil
   bufstates[bufnr].enabled = false
@@ -242,9 +238,7 @@ end
 --- Enable inlay hints for a buffer
 ---@param bufnr (integer) Buffer handle, or 0 for current
 local function _enable(bufnr)
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
   bufstates[bufnr] = nil
   bufstates[bufnr].enabled = true
   _refresh(bufnr)
@@ -371,13 +365,10 @@ function M.is_enabled(filter)
   filter = filter or {}
   local bufnr = filter.bufnr
 
-  vim.validate('bufnr', bufnr, 'number', true)
   if bufnr == nil then
     return globalstate.enabled
-  elseif bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
   end
-  return bufstates[bufnr].enabled
+  return bufstates[vim._resolve_bufnr(bufnr)].enabled
 end
 
 --- Optional filters |kwargs|, or `nil` for all.
diff --git a/runtime/lua/vim/lsp/protocol.lua b/runtime/lua/vim/lsp/protocol.lua
index 7db48b0c06..fbfd0cd6b0 100644
--- a/runtime/lua/vim/lsp/protocol.lua
+++ b/runtime/lua/vim/lsp/protocol.lua
@@ -15,7 +15,6 @@ local sysname = vim.uv.os_uname().sysname
 --- @class vim.lsp.protocol.constants
 --- @nodoc
 local constants = {
-  --- @enum lsp.DiagnosticSeverity
   DiagnosticSeverity = {
     -- Reports an error.
     Error = 1,
@@ -27,7 +26,6 @@ local constants = {
     Hint = 4,
   },
 
-  --- @enum lsp.DiagnosticTag
   DiagnosticTag = {
     -- Unused or unnecessary code
     Unnecessary = 1,
@@ -35,7 +33,6 @@ local constants = {
     Deprecated = 2,
   },
 
-  ---@enum lsp.MessageType
   MessageType = {
     -- An error message.
     Error = 1,
@@ -50,7 +47,6 @@ local constants = {
   },
 
   -- The file event type.
-  ---@enum lsp.FileChangeType
   FileChangeType = {
     -- The file got created.
     Created = 1,
@@ -149,7 +145,6 @@ local constants = {
   },
 
   -- Represents reasons why a text document is saved.
-  ---@enum lsp.TextDocumentSaveReason
   TextDocumentSaveReason = {
     -- Manually triggered, e.g. by the user pressing save, by starting debugging,
     -- or by an API call.
@@ -174,6 +169,7 @@ local constants = {
     -- Defined by the protocol.
     RequestCancelled = -32800,
     ContentModified = -32801,
+    ServerCancelled = -32802,
   },
 
   -- Describes the content type that a client supports in various
@@ -245,7 +241,6 @@ local constants = {
 
   -- Defines whether the insert text in a completion item should be interpreted as
   -- plain text or a snippet.
-  --- @enum lsp.InsertTextFormat
   InsertTextFormat = {
     -- The primary text to be inserted is treated as a plain string.
     PlainText = 1,
@@ -304,7 +299,6 @@ local constants = {
     SourceOrganizeImports = 'source.organizeImports',
   },
   -- The reason why code actions were requested.
-  ---@enum lsp.CodeActionTriggerKind
   CodeActionTriggerKind = {
     -- Code actions were explicitly requested by the user or by an extension.
     Invoked = 1,
@@ -439,6 +433,13 @@ function protocol.make_client_capabilities()
           properties = { 'command' },
         },
       },
+      foldingRange = {
+        dynamicRegistration = false,
+        lineFoldingOnly = true,
+        foldingRange = {
+          collapsedText = true,
+        },
+      },
       formatting = {
         dynamicRegistration = true,
       },
diff --git a/runtime/lua/vim/lsp/rpc.lua b/runtime/lua/vim/lsp/rpc.lua
index 6c8564845f..a0d1fe776b 100644
--- a/runtime/lua/vim/lsp/rpc.lua
+++ b/runtime/lua/vim/lsp/rpc.lua
@@ -1,18 +1,8 @@
-local uv = vim.uv
 local log = require('vim.lsp.log')
 local protocol = require('vim.lsp.protocol')
+local lsp_transport = require('vim.lsp._transport')
 local validate, schedule_wrap = vim.validate, vim.schedule_wrap
 
-local is_win = vim.fn.has('win32') == 1
-
---- Checks whether a given path exists and is a directory.
----@param filename string path to check
----@return boolean
-local function is_dir(filename)
-  local stat = uv.fs_stat(filename)
-  return stat and stat.type == 'directory' or false
-end
-
 --- Embeds the given string into a table and correctly computes `Content-Length`.
 ---
 ---@param message string
@@ -242,8 +232,11 @@ local default_dispatchers = {
   end,
 }
 
----@private
-function M.create_read_loop(handle_body, on_no_chunk, on_error)
+--- @private
+--- @param handle_body fun(body: string)
+--- @param on_exit? fun()
+--- @param on_error fun(err: any)
+function M.create_read_loop(handle_body, on_exit, on_error)
   local parse_chunk = coroutine.wrap(request_parser_loop) --[[@as fun(chunk: string?): vim.lsp.rpc.Headers?, string?]]
   parse_chunk()
   return function(err, chunk)
@@ -253,8 +246,8 @@ function M.create_read_loop(handle_body, on_no_chunk, on_error)
     end
 
     if not chunk then
-      if on_no_chunk then
-        on_no_chunk()
+      if on_exit then
+        on_exit()
       end
       return
     end
@@ -262,7 +255,7 @@ function M.create_read_loop(handle_body, on_no_chunk, on_error)
     while true do
       local headers, body = parse_chunk(chunk)
       if headers then
-        handle_body(body)
+        handle_body(assert(body))
         chunk = ''
       else
         break
@@ -282,14 +275,14 @@ local Client = {}
 ---@private
 function Client:encode_and_send(payload)
   log.debug('rpc.send', payload)
-  if self.transport.is_closing() then
+  if self.transport:is_closing() then
     return false
   end
   local jsonstr = assert(
     vim.json.encode(payload),
     string.format("Couldn't encode payload '%s'", vim.inspect(payload))
   )
-  self.transport.write(format_message_with_content_length(jsonstr))
+  self.transport:write(format_message_with_content_length(jsonstr))
   return true
 end
 
@@ -323,7 +316,7 @@ end
 ---@param method string The invoked LSP method
 ---@param params table? Parameters for the invoked LSP method
 ---@param callback fun(err?: lsp.ResponseError, result: any) Callback to invoke
----@param notify_reply_callback fun(message_id: integer)|nil Callback to invoke as soon as a request is no longer pending
+---@param notify_reply_callback? fun(message_id: integer) Callback to invoke as soon as a request is no longer pending
 ---@return boolean success `true` if request could be sent, `false` if not
 ---@return integer? message_id if request could be sent, `nil` if not
 function Client:request(method, params, callback, notify_reply_callback)
@@ -337,21 +330,16 @@ function Client:request(method, params, callback, notify_reply_callback)
     method = method,
     params = params,
   })
-  local message_callbacks = self.message_callbacks
-  local notify_reply_callbacks = self.notify_reply_callbacks
-  if result then
-    if message_callbacks then
-      message_callbacks[message_id] = schedule_wrap(callback)
-    else
-      return false, nil
-    end
-    if notify_reply_callback and notify_reply_callbacks then
-      notify_reply_callbacks[message_id] = schedule_wrap(notify_reply_callback)
-    end
-    return result, message_id
-  else
-    return false, nil
+
+  if not result then
+    return false
+  end
+
+  self.message_callbacks[message_id] = schedule_wrap(callback)
+  if notify_reply_callback then
+    self.notify_reply_callbacks[message_id] = schedule_wrap(notify_reply_callback)
   end
+  return result, message_id
 end
 
 ---@package
@@ -370,7 +358,7 @@ end
 ---@param ... any
 ---@return boolean status
 ---@return any head
----@return any|nil ...
+---@return any? ...
 function Client:pcall_handler(errkind, status, head, ...)
   if not status then
     self:on_error(errkind, head, ...)
@@ -385,7 +373,7 @@ end
 ---@param ... any
 ---@return boolean status
 ---@return any head
----@return any|nil ...
+---@return any? ...
 function Client:try_call(errkind, fn, ...)
   return self:pcall_handler(errkind, pcall(fn, ...))
 end
@@ -394,7 +382,8 @@ end
 -- time and log them. This would require storing the timestamp. I could call
 -- them with an error then, perhaps.
 
----@package
+--- @package
+--- @param body string
 function Client:handle_body(body)
   local ok, decoded = pcall(vim.json.decode, body, { luanil = { object = true } })
   if not ok then
@@ -406,7 +395,7 @@ function Client:handle_body(body)
   if type(decoded) ~= 'table' then
     self:on_error(M.client_errors.INVALID_SERVER_MESSAGE, decoded)
   elseif type(decoded.method) == 'string' and decoded.id then
-    local err --- @type lsp.ResponseError|nil
+    local err --- @type lsp.ResponseError?
     -- Schedule here so that the users functions don't trigger an error and
     -- we can still use the result.
     vim.schedule(coroutine.wrap(function()
@@ -453,45 +442,36 @@ function Client:handle_body(body)
     local result_id = assert(tonumber(decoded.id), 'response id must be a number')
 
     -- Notify the user that a response was received for the request
-    local notify_reply_callbacks = self.notify_reply_callbacks
-    local notify_reply_callback = notify_reply_callbacks and notify_reply_callbacks[result_id]
+    local notify_reply_callback = self.notify_reply_callbacks[result_id]
     if notify_reply_callback then
       validate('notify_reply_callback', notify_reply_callback, 'function')
       notify_reply_callback(result_id)
-      notify_reply_callbacks[result_id] = nil
+      self.notify_reply_callbacks[result_id] = nil
     end
 
-    local message_callbacks = self.message_callbacks
-
     -- Do not surface RequestCancelled to users, it is RPC-internal.
     if decoded.error then
-      local mute_error = false
+      assert(type(decoded.error) == 'table')
       if decoded.error.code == protocol.ErrorCodes.RequestCancelled then
         log.debug('Received cancellation ack', decoded)
-        mute_error = true
-      end
-
-      if mute_error then
         -- Clear any callback since this is cancelled now.
         -- This is safe to do assuming that these conditions hold:
         -- - The server will not send a result callback after this cancellation.
         -- - If the server sent this cancellation ACK after sending the result, the user of this RPC
         -- client will ignore the result themselves.
-        if result_id and message_callbacks then
-          message_callbacks[result_id] = nil
+        if result_id then
+          self.message_callbacks[result_id] = nil
         end
         return
       end
     end
 
-    local callback = message_callbacks and message_callbacks[result_id]
+    local callback = self.message_callbacks[result_id]
     if callback then
-      message_callbacks[result_id] = nil
+      self.message_callbacks[result_id] = nil
       validate('callback', callback, 'function')
       if decoded.error then
-        decoded.error = setmetatable(decoded.error, {
-          __tostring = M.format_rpc_error,
-        })
+        setmetatable(decoded.error, { __tostring = M.format_rpc_error })
       end
       self:try_call(
         M.client_errors.SERVER_RESULT_CALLBACK_ERROR,
@@ -517,11 +497,6 @@ function Client:handle_body(body)
   end
 end
 
----@class (private) vim.lsp.rpc.Transport
----@field write fun(msg: string)
----@field is_closing fun(): boolean
----@field terminate fun()
-
 ---@param dispatchers vim.lsp.rpc.Dispatchers
 ---@param transport vim.lsp.rpc.Transport
 ---@return vim.lsp.rpc.Client
@@ -536,11 +511,20 @@ local function new_client(dispatchers, transport)
   return setmetatable(state, { __index = Client })
 end
 
----@class vim.lsp.rpc.PublicClient
----@field request fun(method: string, params: table?, callback: fun(err: lsp.ResponseError|nil, result: any), notify_reply_callback: fun(message_id: integer)|nil):boolean,integer? see |vim.lsp.rpc.request()|
----@field notify fun(method: string, params: any):boolean see |vim.lsp.rpc.notify()|
----@field is_closing fun(): boolean
----@field terminate fun()
+--- Client RPC object
+--- @class vim.lsp.rpc.PublicClient
+---
+--- See [vim.lsp.rpc.request()]
+--- @field request fun(method: string, params: table?, callback: fun(err?: lsp.ResponseError, result: any), notify_reply_callback?: fun(message_id: integer)):boolean,integer?
+---
+--- See [vim.lsp.rpc.notify()]
+--- @field notify fun(method: string, params: any): boolean
+---
+--- Indicates if the RPC is closing.
+--- @field is_closing fun(): boolean
+---
+--- Terminates the RPC client.
+--- @field terminate fun()
 
 ---@param client vim.lsp.rpc.Client
 ---@return vim.lsp.rpc.PublicClient
@@ -551,20 +535,20 @@ local function public_client(client)
 
   ---@private
   function result.is_closing()
-    return client.transport.is_closing()
+    return client.transport:is_closing()
   end
 
   ---@private
   function result.terminate()
-    client.transport.terminate()
+    client.transport:terminate()
   end
 
   --- Sends a request to the LSP server and runs {callback} upon response.
   ---
   ---@param method (string) The invoked LSP method
   ---@param params (table?) Parameters for the invoked LSP method
-  ---@param callback fun(err: lsp.ResponseError|nil, result: any) Callback to invoke
-  ---@param notify_reply_callback fun(message_id: integer)|nil Callback to invoke as soon as a request is no longer pending
+  ---@param callback fun(err: lsp.ResponseError?, result: any) Callback to invoke
+  ---@param notify_reply_callback? fun(message_id: integer) Callback to invoke as soon as a request is no longer pending
   ---@return boolean success `true` if request could be sent, `false` if not
   ---@return integer? message_id if request could be sent, `nil` if not
   function result.request(method, params, callback, notify_reply_callback)
@@ -610,6 +594,21 @@ local function merge_dispatchers(dispatchers)
   return merged
 end
 
+--- @param client vim.lsp.rpc.Client
+--- @param on_exit? fun()
+local function create_client_read_loop(client, on_exit)
+  --- @param body string
+  local function handle_body(body)
+    client:handle_body(body)
+  end
+
+  local function on_error(err)
+    client:on_error(M.client_errors.READ_ERROR, err)
+  end
+
+  return M.create_read_loop(handle_body, on_exit, on_error)
+end
+
 --- Create a LSP RPC client factory that connects to either:
 ---
 ---  - a named pipe (windows)
@@ -617,83 +616,26 @@ end
 ---  - a host and port via TCP
 ---
 --- Return a function that can be passed to the `cmd` field for
---- |vim.lsp.start_client()| or |vim.lsp.start()|.
+--- |vim.lsp.start()|.
 ---
 ---@param host_or_path string host to connect to or path to a pipe/domain socket
 ---@param port integer? TCP port to connect to. If absent the first argument must be a pipe
 ---@return fun(dispatchers: vim.lsp.rpc.Dispatchers): vim.lsp.rpc.PublicClient
 function M.connect(host_or_path, port)
+  validate('host_or_path', host_or_path, 'string')
+  validate('port', port, 'number', true)
+
   return function(dispatchers)
+    validate('dispatchers', dispatchers, 'table', true)
+
     dispatchers = merge_dispatchers(dispatchers)
-    local handle = (
-      port == nil
-        and assert(
-          uv.new_pipe(false),
-          string.format('Pipe with name %s could not be opened.', host_or_path)
-        )
-      or assert(uv.new_tcp(), 'Could not create new TCP socket')
-    )
-    local closing = false
-    -- Connect returns a PublicClient synchronously so the caller
-    -- can immediately send messages before the connection is established
-    -- -> Need to buffer them until that happens
-    local connected = false
-    -- size should be enough because the client can't really do anything until initialization is done
-    -- which required a response from the server - implying the connection got established
-    local msgbuf = vim.ringbuf(10)
-    local transport = {
-      write = function(msg)
-        if connected then
-          local _, err = handle:write(msg)
-          if err and not closing then
-            log.error('Error on handle:write: %q', err)
-          end
-        else
-          msgbuf:push(msg)
-        end
-      end,
-      is_closing = function()
-        return closing
-      end,
-      terminate = function()
-        if not closing then
-          closing = true
-          handle:shutdown()
-          handle:close()
-          dispatchers.on_exit(0, 0)
-        end
-      end,
-    }
+
+    local transport = lsp_transport.TransportConnect.new()
     local client = new_client(dispatchers, transport)
-    local function on_connect(err)
-      if err then
-        local address = port == nil and host_or_path or (host_or_path .. ':' .. port)
-        vim.schedule(function()
-          vim.notify(
-            string.format('Could not connect to %s, reason: %s', address, vim.inspect(err)),
-            vim.log.levels.WARN
-          )
-        end)
-        return
-      end
-      local handle_body = function(body)
-        client:handle_body(body)
-      end
-      handle:read_start(M.create_read_loop(handle_body, transport.terminate, function(read_err)
-        client:on_error(M.client_errors.READ_ERROR, read_err)
-      end))
-      connected = true
-      for msg in msgbuf do
-        handle:write(msg)
-      end
-    end
-    if port == nil then
-      handle:connect(host_or_path, on_connect)
-    else
-      local info = uv.getaddrinfo(host_or_path, nil)
-      local resolved_host = info and info[1] and info[1].addr or host_or_path
-      handle:connect(resolved_host, port, on_connect)
-    end
+    local on_read = create_client_read_loop(client, function()
+      transport:terminate()
+    end)
+    transport:connect(host_or_path, port, on_read, dispatchers.on_exit)
 
     return public_client(client)
   end
@@ -713,83 +655,19 @@ end
 --- @param cmd string[] Command to start the LSP server.
 --- @param dispatchers? vim.lsp.rpc.Dispatchers
 --- @param extra_spawn_params? vim.lsp.rpc.ExtraSpawnParams
---- @return vim.lsp.rpc.PublicClient : Client RPC object, with these methods:
----   - `notify()` |vim.lsp.rpc.notify()|
----   - `request()` |vim.lsp.rpc.request()|
----   - `is_closing()` returns a boolean indicating if the RPC is closing.
----   - `terminate()` terminates the RPC client.
+--- @return vim.lsp.rpc.PublicClient
 function M.start(cmd, dispatchers, extra_spawn_params)
   log.info('Starting RPC client', { cmd = cmd, extra = extra_spawn_params })
 
   validate('cmd', cmd, 'table')
   validate('dispatchers', dispatchers, 'table', true)
 
-  extra_spawn_params = extra_spawn_params or {}
-
-  if extra_spawn_params.cwd then
-    assert(is_dir(extra_spawn_params.cwd), 'cwd must be a directory')
-  end
-
   dispatchers = merge_dispatchers(dispatchers)
 
-  local sysobj ---@type vim.SystemObj
-
-  local client = new_client(dispatchers, {
-    write = function(msg)
-      sysobj:write(msg)
-    end,
-    is_closing = function()
-      return sysobj == nil or sysobj:is_closing()
-    end,
-    terminate = function()
-      sysobj:kill(15)
-    end,
-  })
-
-  local handle_body = function(body)
-    client:handle_body(body)
-  end
-
-  local stdout_handler = M.create_read_loop(handle_body, nil, function(err)
-    client:on_error(M.client_errors.READ_ERROR, err)
-  end)
-
-  local stderr_handler = function(_, chunk)
-    if chunk then
-      log.error('rpc', cmd[1], 'stderr', chunk)
-    end
-  end
-
-  local detached = not is_win
-  if extra_spawn_params.detached ~= nil then
-    detached = extra_spawn_params.detached
-  end
-
-  local ok, sysobj_or_err = pcall(vim.system, cmd, {
-    stdin = true,
-    stdout = stdout_handler,
-    stderr = stderr_handler,
-    cwd = extra_spawn_params.cwd,
-    env = extra_spawn_params.env,
-    detach = detached,
-  }, function(obj)
-    dispatchers.on_exit(obj.code, obj.signal)
-  end)
-
-  if not ok then
-    local err = sysobj_or_err --[[@as string]]
-    local sfx --- @type string
-    if string.match(err, 'ENOENT') then
-      sfx = '. The language server is either not installed, missing from PATH, or not executable.'
-    else
-      sfx = string.format(' with error message: %s', err)
-    end
-    local msg =
-      string.format('Spawning language server with cmd: `%s` failed%s', vim.inspect(cmd), sfx)
-    error(msg)
-  end
-
-  sysobj = sysobj_or_err --[[@as vim.SystemObj]]
+  local transport = lsp_transport.TransportRun.new()
+  local client = new_client(dispatchers, transport)
+  local on_read = create_client_read_loop(client)
+  transport:run(cmd, extra_spawn_params, on_read, dispatchers.on_exit)
 
   return public_client(client)
 end
diff --git a/runtime/lua/vim/lsp/semantic_tokens.lua b/runtime/lua/vim/lsp/semantic_tokens.lua
index 215e5f41aa..dd8b654856 100644
--- a/runtime/lua/vim/lsp/semantic_tokens.lua
+++ b/runtime/lua/vim/lsp/semantic_tokens.lua
@@ -139,7 +139,7 @@ local function tokens_to_ranges(data, bufnr, client, request)
 
     if token_type then
       local modifiers = modifiers_from_number(data[i + 4], token_modifiers)
-      local end_char = start_char + data[i + 2]
+      local end_char = start_char + data[i + 2] --- @type integer LuaLS bug
       local buf_line = lines and lines[line + 1] or ''
       local start_col = vim.str_byteindex(buf_line, encoding, start_char, false)
       local end_col = vim.str_byteindex(buf_line, encoding, end_char, false)
@@ -166,7 +166,7 @@ function STHighlighter.new(bufnr)
   local self = setmetatable({}, { __index = STHighlighter })
 
   self.bufnr = bufnr
-  self.augroup = api.nvim_create_augroup('vim_lsp_semantic_tokens:' .. bufnr, { clear = true })
+  self.augroup = api.nvim_create_augroup('nvim.lsp.semantic_tokens:' .. bufnr, { clear = true })
   self.client_state = {}
 
   STHighlighter.active[bufnr] = self
@@ -225,7 +225,7 @@ function STHighlighter:attach(client_id)
   local state = self.client_state[client_id]
   if not state then
     state = {
-      namespace = api.nvim_create_namespace('vim_lsp_semantic_tokens:' .. client_id),
+      namespace = api.nvim_create_namespace('nvim.lsp.semantic_tokens:' .. client_id),
       active_request = {},
       current_result = {},
     }
@@ -273,7 +273,7 @@ function STHighlighter:send_request()
     if client and current_result.version ~= version and active_request.version ~= version then
       -- cancel stale in-flight request
       if active_request.request_id then
-        client.cancel_request(active_request.request_id)
+        client:cancel_request(active_request.request_id)
         active_request = {}
         state.active_request = active_request
       end
@@ -288,7 +288,7 @@ function STHighlighter:send_request()
         method = method .. '/delta'
         params.previousResultId = current_result.result_id
       end
-      local success, request_id = client.request(method, params, function(err, response, ctx)
+      local success, request_id = client:request(method, params, function(err, response, ctx)
         -- look client up again using ctx.client_id instead of using a captured
         -- client object
         local c = vim.lsp.get_client_by_id(ctx.client_id)
@@ -519,7 +519,7 @@ function STHighlighter:reset()
     if state.active_request.request_id then
       local client = vim.lsp.get_client_by_id(client_id)
       assert(client)
-      client.cancel_request(state.active_request.request_id)
+      client:cancel_request(state.active_request.request_id)
       state.active_request = {}
     end
   end
@@ -547,7 +547,7 @@ function STHighlighter:mark_dirty(client_id)
   if state.active_request.request_id then
     local client = vim.lsp.get_client_by_id(client_id)
     assert(client)
-    client.cancel_request(state.active_request.request_id)
+    client:cancel_request(state.active_request.request_id)
     state.active_request = {}
   end
 end
@@ -600,9 +600,7 @@ function M.start(bufnr, client_id, opts)
   vim.validate('bufnr', bufnr, 'number')
   vim.validate('client_id', client_id, 'number')
 
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
 
   opts = opts or {}
   assert(
@@ -655,9 +653,7 @@ function M.stop(bufnr, client_id)
   vim.validate('bufnr', bufnr, 'number')
   vim.validate('client_id', client_id, 'number')
 
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
 
   local highlighter = STHighlighter.active[bufnr]
   if not highlighter then
@@ -691,9 +687,7 @@ end
 ---        - modifiers (table) token modifiers as a set. E.g., { static = true, readonly = true }
 ---        - client_id (integer)
 function M.get_at_pos(bufnr, row, col)
-  if bufnr == nil or bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
 
   local highlighter = STHighlighter.active[bufnr]
   if not highlighter then
@@ -739,8 +733,7 @@ function M.force_refresh(bufnr)
   vim.validate('bufnr', bufnr, 'number', true)
 
   local buffers = bufnr == nil and vim.tbl_keys(STHighlighter.active)
-    or bufnr == 0 and { api.nvim_get_current_buf() }
-    or { bufnr }
+    or { vim._resolve_bufnr(bufnr) }
 
   for _, buffer in ipairs(buffers) do
     local highlighter = STHighlighter.active[buffer]
@@ -770,9 +763,7 @@ end
 ---@param hl_group (string) Highlight group name
 ---@param opts? vim.lsp.semantic_tokens.highlight_token.Opts  Optional parameters:
 function M.highlight_token(token, bufnr, client_id, hl_group, opts)
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
   local highlighter = STHighlighter.active[bufnr]
   if not highlighter then
     return
@@ -814,7 +805,7 @@ function M._refresh(err, _, ctx)
   return vim.NIL
 end
 
-local namespace = api.nvim_create_namespace('vim_lsp_semantic_tokens')
+local namespace = api.nvim_create_namespace('nvim.lsp.semantic_tokens')
 api.nvim_set_decoration_provider(namespace, {
   on_win = function(_, _, bufnr, topline, botline)
     local highlighter = STHighlighter.active[bufnr]
diff --git a/runtime/lua/vim/lsp/sync.lua b/runtime/lua/vim/lsp/sync.lua
index 3df45ebff0..621f63b25f 100644
--- a/runtime/lua/vim/lsp/sync.lua
+++ b/runtime/lua/vim/lsp/sync.lua
@@ -48,21 +48,21 @@ local str_utfindex = vim.str_utfindex
 local str_utf_start = vim.str_utf_start
 local str_utf_end = vim.str_utf_end
 
--- Given a line, byte idx, alignment, and offset_encoding convert to the aligned
+-- Given a line, byte idx, alignment, and position_encoding convert to the aligned
 -- utf-8 index and either the utf-16, or utf-32 index.
 ---@param line string the line to index into
 ---@param byte integer the byte idx
----@param offset_encoding string utf-8|utf-16|utf-32|nil (default: utf-8)
+---@param position_encoding string utf-8|utf-16|utf-32|nil (default: utf-8)
 ---@return integer byte_idx of first change position
 ---@return integer char_idx of first change position
-local function align_end_position(line, byte, offset_encoding)
+local function align_end_position(line, byte, position_encoding)
   local char --- @type integer
   -- If on the first byte, or an empty string: the trivial case
   if byte == 1 or #line == 0 then
     char = byte
     -- Called in the case of extending an empty line "" -> "a"
   elseif byte == #line + 1 then
-    char = str_utfindex(line, offset_encoding) + 1
+    char = str_utfindex(line, position_encoding) + 1
   else
     -- Modifying line, find the nearest utf codepoint
     local offset = str_utf_start(line, byte)
@@ -73,9 +73,9 @@ local function align_end_position(line, byte, offset_encoding)
     end
     if byte <= #line then
       --- Convert to 0 based for input, and from 0 based for output
-      char = str_utfindex(line, offset_encoding, byte - 1) + 1
+      char = str_utfindex(line, position_encoding, byte - 1) + 1
     else
-      char = str_utfindex(line, offset_encoding) + 1
+      char = str_utfindex(line, position_encoding) + 1
     end
     -- Extending line, find the nearest utf codepoint for the last valid character
   end
@@ -93,7 +93,7 @@ end
 ---@param firstline integer firstline from on_lines, adjusted to 1-index
 ---@param lastline integer lastline from on_lines, adjusted to 1-index
 ---@param new_lastline integer new_lastline from on_lines, adjusted to 1-index
----@param offset_encoding string utf-8|utf-16|utf-32|nil (fallback to utf-8)
+---@param position_encoding string utf-8|utf-16|utf-32|nil (fallback to utf-8)
 ---@return vim.lsp.sync.Range result table include line_idx, byte_idx, and char_idx of first change position
 local function compute_start_range(
   prev_lines,
@@ -101,7 +101,7 @@ local function compute_start_range(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding
+  position_encoding
 )
   local char_idx --- @type integer?
   local byte_idx --- @type integer?
@@ -115,7 +115,7 @@ local function compute_start_range(
     if line then
       line_idx = firstline - 1
       byte_idx = #line + 1
-      char_idx = str_utfindex(line, offset_encoding) + 1
+      char_idx = str_utfindex(line, position_encoding) + 1
     else
       line_idx = firstline
       byte_idx = 1
@@ -152,11 +152,11 @@ local function compute_start_range(
     char_idx = 1
   elseif start_byte_idx == #prev_line + 1 then
     byte_idx = start_byte_idx
-    char_idx = str_utfindex(prev_line, offset_encoding) + 1
+    char_idx = str_utfindex(prev_line, position_encoding) + 1
   else
     byte_idx = start_byte_idx + str_utf_start(prev_line, start_byte_idx)
     --- Convert to 0 based for input, and from 0 based for output
-    char_idx = vim.str_utfindex(prev_line, offset_encoding, byte_idx - 1) + 1
+    char_idx = vim.str_utfindex(prev_line, position_encoding, byte_idx - 1) + 1
   end
 
   -- Return the start difference (shared for new and prev lines)
@@ -174,7 +174,7 @@ end
 ---@param firstline integer
 ---@param lastline integer
 ---@param new_lastline integer
----@param offset_encoding string
+---@param position_encoding string
 ---@return vim.lsp.sync.Range prev_end_range
 ---@return vim.lsp.sync.Range curr_end_range
 local function compute_end_range(
@@ -184,7 +184,7 @@ local function compute_end_range(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding
+  position_encoding
 )
   -- A special case for the following `firstline == new_lastline` case where lines are deleted.
   -- Even if the buffer has become empty, nvim behaves as if it has an empty line with eol.
@@ -193,7 +193,7 @@ local function compute_end_range(
     return {
       line_idx = lastline - 1,
       byte_idx = #prev_line + 1,
-      char_idx = str_utfindex(prev_line, offset_encoding) + 1,
+      char_idx = str_utfindex(prev_line, position_encoding) + 1,
     }, { line_idx = 1, byte_idx = 1, char_idx = 1 }
   end
   -- If firstline == new_lastline, the first change occurred on a line that was deleted.
@@ -259,7 +259,7 @@ local function compute_end_range(
     prev_end_byte_idx = 1
   end
   local prev_byte_idx, prev_char_idx =
-    align_end_position(prev_line, prev_end_byte_idx, offset_encoding)
+    align_end_position(prev_line, prev_end_byte_idx, position_encoding)
   local prev_end_range =
     { line_idx = prev_line_idx, byte_idx = prev_byte_idx, char_idx = prev_char_idx }
 
@@ -274,7 +274,7 @@ local function compute_end_range(
       curr_end_byte_idx = 1
     end
     local curr_byte_idx, curr_char_idx =
-      align_end_position(curr_line, curr_end_byte_idx, offset_encoding)
+      align_end_position(curr_line, curr_end_byte_idx, position_encoding)
     curr_end_range =
       { line_idx = curr_line_idx, byte_idx = curr_byte_idx, char_idx = curr_char_idx }
   end
@@ -317,7 +317,7 @@ local function extract_text(lines, start_range, end_range, line_ending)
   end
 end
 
--- rangelength depends on the offset encoding
+-- rangelength depends on the position encoding
 -- bytes for utf-8 (clangd with extension)
 -- codepoints for utf-16
 -- codeunits for utf-32
@@ -326,10 +326,10 @@ end
 ---@param lines string[]
 ---@param start_range vim.lsp.sync.Range
 ---@param end_range vim.lsp.sync.Range
----@param offset_encoding string
+---@param position_encoding string
 ---@param line_ending string
 ---@return integer
-local function compute_range_length(lines, start_range, end_range, offset_encoding, line_ending)
+local function compute_range_length(lines, start_range, end_range, position_encoding, line_ending)
   local line_ending_length = #line_ending
   -- Single line case
   if start_range.line_idx == end_range.line_idx then
@@ -339,7 +339,7 @@ local function compute_range_length(lines, start_range, end_range, offset_encodi
   local start_line = lines[start_range.line_idx]
   local range_length --- @type integer
   if start_line and #start_line > 0 then
-    range_length = str_utfindex(start_line, offset_encoding)
+    range_length = str_utfindex(start_line, position_encoding)
       - start_range.char_idx
       + 1
       + line_ending_length
@@ -352,7 +352,7 @@ local function compute_range_length(lines, start_range, end_range, offset_encodi
   for idx = start_range.line_idx + 1, end_range.line_idx - 1 do
     -- Length full line plus newline character
     if #lines[idx] > 0 then
-      range_length = range_length + str_utfindex(lines[idx], offset_encoding) + #line_ending
+      range_length = range_length + str_utfindex(lines[idx], position_encoding) + #line_ending
     else
       range_length = range_length + line_ending_length
     end
@@ -372,7 +372,7 @@ end
 ---@param firstline integer line to begin search for first difference
 ---@param lastline integer line to begin search in old_lines for last difference
 ---@param new_lastline integer line to begin search in new_lines for last difference
----@param offset_encoding string encoding requested by language server
+---@param position_encoding string encoding requested by language server
 ---@param line_ending string
 ---@return lsp.TextDocumentContentChangeEvent : see https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
 function M.compute_diff(
@@ -381,7 +381,7 @@ function M.compute_diff(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding,
+  position_encoding,
   line_ending
 )
   -- Find the start of changes between the previous and current buffer. Common between both.
@@ -393,7 +393,7 @@ function M.compute_diff(
     firstline + 1,
     lastline + 1,
     new_lastline + 1,
-    offset_encoding
+    position_encoding
   )
   -- Find the last position changed in the previous and current buffer.
   -- prev_end_range is sent to the server as as the end of the changed range.
@@ -405,7 +405,7 @@ function M.compute_diff(
     firstline + 1,
     lastline + 1,
     new_lastline + 1,
-    offset_encoding
+    position_encoding
   )
 
   -- Grab the changed text of from start_range to curr_end_range in the current buffer.
@@ -414,7 +414,7 @@ function M.compute_diff(
 
   -- Compute the range of the replaced text. Deprecated but still required for certain language servers
   local range_length =
-    compute_range_length(prev_lines, start_range, prev_end_range, offset_encoding, line_ending)
+    compute_range_length(prev_lines, start_range, prev_end_range, position_encoding, line_ending)
 
   -- convert to 0 based indexing
   local result = {
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 6eab0f3da4..e16a905c44 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -49,7 +49,8 @@ local function get_border_size(opts)
     if not border_size[border] then
       border_error(border)
     end
-    return unpack(border_size[border])
+    local r = border_size[border]
+    return r[1], r[2]
   end
 
   if 8 % #border ~= 0 then
@@ -192,9 +193,7 @@ local function get_lines(bufnr, rows)
   rows = type(rows) == 'table' and rows or { rows }
 
   -- This is needed for bufload and bufloaded
-  if bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  bufnr = vim._resolve_bufnr(bufnr)
 
   local function buf_lines()
     local lines = {} --- @type table<integer,string>
@@ -277,9 +276,9 @@ end
 
 --- Position is a https://microsoft.github.io/language-server-protocol/specifications/specification-current/#position
 ---@param position lsp.Position
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return integer
-local function get_line_byte_from_position(bufnr, position, offset_encoding)
+local function get_line_byte_from_position(bufnr, position, position_encoding)
   -- LSP's line and characters are 0-indexed
   -- Vim's line and columns are 1-indexed
   local col = position.character
@@ -287,7 +286,7 @@ local function get_line_byte_from_position(bufnr, position, offset_encoding)
   -- character
   if col > 0 then
     local line = get_line(bufnr, position.line) or ''
-    return vim.str_byteindex(line, offset_encoding, col, false)
+    return vim.str_byteindex(line, position_encoding, col, false)
   end
   return col
 end
@@ -295,12 +294,12 @@ end
 --- Applies a list of text edits to a buffer.
 ---@param text_edits lsp.TextEdit[]
 ---@param bufnr integer Buffer id
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textEdit
-function M.apply_text_edits(text_edits, bufnr, offset_encoding)
+function M.apply_text_edits(text_edits, bufnr, position_encoding)
   validate('text_edits', text_edits, 'table', false)
   validate('bufnr', bufnr, 'number', false)
-  validate('offset_encoding', offset_encoding, 'string', false)
+  validate('position_encoding', position_encoding, 'string', false)
 
   if not next(text_edits) then
     return
@@ -359,9 +358,9 @@ function M.apply_text_edits(text_edits, bufnr, offset_encoding)
 
     -- Convert from LSP style ranges to Neovim style ranges.
     local start_row = text_edit.range.start.line
-    local start_col = get_line_byte_from_position(bufnr, text_edit.range.start, offset_encoding)
+    local start_col = get_line_byte_from_position(bufnr, text_edit.range.start, position_encoding)
     local end_row = text_edit.range['end'].line
-    local end_col = get_line_byte_from_position(bufnr, text_edit.range['end'], offset_encoding)
+    local end_col = get_line_byte_from_position(bufnr, text_edit.range['end'], position_encoding)
     local text = vim.split(text_edit.newText, '\n', { plain = true })
 
     local max = api.nvim_buf_line_count(bufnr)
@@ -430,14 +429,14 @@ end
 ---
 ---@param text_document_edit lsp.TextDocumentEdit
 ---@param index? integer: Optional index of the edit, if from a list of edits (or nil, if not from a list)
----@param offset_encoding? 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentEdit
-function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
+function M.apply_text_document_edit(text_document_edit, index, position_encoding)
   local text_document = text_document_edit.textDocument
   local bufnr = vim.uri_to_bufnr(text_document.uri)
-  if offset_encoding == nil then
+  if position_encoding == nil then
     vim.notify_once(
-      'apply_text_document_edit must be called with valid offset encoding',
+      'apply_text_document_edit must be called with valid position encoding',
       vim.log.levels.WARN
     )
     return
@@ -459,7 +458,7 @@ function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
     return
   end
 
-  M.apply_text_edits(text_document_edit.edits, bufnr, offset_encoding)
+  M.apply_text_edits(text_document_edit.edits, bufnr, position_encoding)
 end
 
 local function path_components(path)
@@ -619,12 +618,12 @@ end
 --- Applies a `WorkspaceEdit`.
 ---
 ---@param workspace_edit lsp.WorkspaceEdit
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32' (required)
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32' (required)
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_applyEdit
-function M.apply_workspace_edit(workspace_edit, offset_encoding)
-  if offset_encoding == nil then
+function M.apply_workspace_edit(workspace_edit, position_encoding)
+  if position_encoding == nil then
     vim.notify_once(
-      'apply_workspace_edit must be called with valid offset encoding',
+      'apply_workspace_edit must be called with valid position encoding',
       vim.log.levels.WARN
     )
     return
@@ -641,7 +640,7 @@ function M.apply_workspace_edit(workspace_edit, offset_encoding)
       elseif change.kind then --- @diagnostic disable-line:undefined-field
         error(string.format('Unsupported change: %q', vim.inspect(change)))
       else
-        M.apply_text_document_edit(change, idx, offset_encoding)
+        M.apply_text_document_edit(change, idx, position_encoding)
       end
     end
     return
@@ -654,7 +653,7 @@ function M.apply_workspace_edit(workspace_edit, offset_encoding)
 
   for uri, changes in pairs(all_changes) do
     local bufnr = vim.uri_to_bufnr(uri)
-    M.apply_text_edits(changes, bufnr, offset_encoding)
+    M.apply_text_edits(changes, bufnr, position_encoding)
   end
 end
 
@@ -877,15 +876,16 @@ function M.make_floating_popup_options(width, height, opts)
 
   return {
     anchor = anchor,
+    row = row + (opts.offset_y or 0),
     col = col + (opts.offset_x or 0),
     height = height,
     focusable = opts.focusable,
-    relative = opts.relative == 'mouse' and 'mouse' or 'cursor',
-    row = row + (opts.offset_y or 0),
+    relative = (opts.relative == 'mouse' or opts.relative == 'editor') and opts.relative
+      or 'cursor',
     style = 'minimal',
     width = width,
     border = opts.border or default_border,
-    zindex = opts.zindex or 50,
+    zindex = opts.zindex or (api.nvim_win_get_config(0).zindex or 49) + 1,
     title = title,
     title_pos = title_pos,
   }
@@ -904,17 +904,20 @@ end
 --- Shows document and optionally jumps to the location.
 ---
 ---@param location lsp.Location|lsp.LocationLink
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'?
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'?
 ---@param opts? vim.lsp.util.show_document.Opts
 ---@return boolean `true` if succeeded
-function M.show_document(location, offset_encoding, opts)
+function M.show_document(location, position_encoding, opts)
   -- location may be Location or LocationLink
   local uri = location.uri or location.targetUri
   if uri == nil then
     return false
   end
-  if offset_encoding == nil then
-    vim.notify_once('show_document must be called with valid offset encoding', vim.log.levels.WARN)
+  if position_encoding == nil then
+    vim.notify_once(
+      'show_document must be called with valid position encoding',
+      vim.log.levels.WARN
+    )
     return false
   end
   local bufnr = vim.uri_to_bufnr(uri)
@@ -946,7 +949,7 @@ function M.show_document(location, offset_encoding, opts)
   if range then
     -- Jump to new location (adjusting for encoding of characters)
     local row = range.start.line
-    local col = get_line_byte_from_position(bufnr, range.start, offset_encoding)
+    local col = get_line_byte_from_position(bufnr, range.start, position_encoding)
     api.nvim_win_set_cursor(win, { row + 1, col })
     vim._with({ win = win }, function()
       -- Open folds under the cursor
@@ -961,12 +964,12 @@ end
 ---
 ---@deprecated use `vim.lsp.util.show_document` with `{focus=true}` instead
 ---@param location lsp.Location|lsp.LocationLink
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'?
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'?
 ---@param reuse_win boolean? Jump to existing window if buffer is already open.
 ---@return boolean `true` if the jump succeeded
-function M.jump_to_location(location, offset_encoding, reuse_win)
+function M.jump_to_location(location, position_encoding, reuse_win)
   vim.deprecate('vim.lsp.util.jump_to_location', nil, '0.12')
-  return M.show_document(location, offset_encoding, { reuse_win = reuse_win, focus = true })
+  return M.show_document(location, position_encoding, { reuse_win = reuse_win, focus = true })
 end
 
 --- Previews a location in a floating window
@@ -1355,7 +1358,7 @@ end
 ---@param bufnrs table list of buffers where the preview window will remain visible
 ---@see autocmd-events
 local function close_preview_autocmd(events, winnr, bufnrs)
-  local augroup = api.nvim_create_augroup('preview_window_' .. winnr, {
+  local augroup = api.nvim_create_augroup('nvim.preview_window_' .. winnr, {
     clear = true,
   })
 
@@ -1430,7 +1433,7 @@ function M._make_floating_popup_size(contents, opts)
       if vim.tbl_isempty(line_widths) then
         for _, line in ipairs(contents) do
           local line_width = vim.fn.strdisplaywidth(line:gsub('%z', '\n'))
-          height = height + math.ceil(line_width / wrap_at)
+          height = height + math.max(1, math.ceil(line_width / wrap_at))
         end
       else
         for i = 1, #contents do
@@ -1493,7 +1496,7 @@ end
 --- @field title_pos? 'left'|'center'|'right'
 ---
 --- (default: `'cursor'`)
---- @field relative? 'mouse'|'cursor'
+--- @field relative? 'mouse'|'cursor'|'editor'
 ---
 --- - "auto": place window based on which side of the cursor has more lines
 --- - "above": place the window above the cursor unless there are not enough lines
@@ -1566,8 +1569,6 @@ function M.open_floating_preview(contents, syntax, opts)
   if do_stylize then
     local width = M._make_floating_popup_size(contents, opts)
     contents = M._normalize_markdown(contents, { width = width })
-    vim.bo[floating_bufnr].filetype = 'markdown'
-    vim.treesitter.start(floating_bufnr)
   else
     -- Clean up input: trim empty lines
     contents = vim.split(table.concat(contents, '\n'), '\n', { trimempty = true })
@@ -1617,9 +1618,22 @@ function M.open_floating_preview(contents, syntax, opts)
     api.nvim_buf_set_var(bufnr, 'lsp_floating_preview', floating_winnr)
   end
 
-  if do_stylize then
-    vim.wo[floating_winnr].conceallevel = 2
+  local augroup_name = ('nvim.closing_floating_preview_%d'):format(floating_winnr)
+  local ok =
+    pcall(api.nvim_get_autocmds, { group = augroup_name, pattern = tostring(floating_winnr) })
+  if not ok then
+    api.nvim_create_autocmd('WinClosed', {
+      group = api.nvim_create_augroup(augroup_name, {}),
+      pattern = tostring(floating_winnr),
+      callback = function()
+        if api.nvim_buf_is_valid(bufnr) then
+          vim.b[bufnr].lsp_floating_preview = nil
+        end
+        api.nvim_del_augroup_by_name(augroup_name)
+      end,
+    })
   end
+
   vim.wo[floating_winnr].foldenable = false -- Disable folding.
   vim.wo[floating_winnr].wrap = opts.wrap -- Soft wrapping.
   vim.wo[floating_winnr].breakindent = true -- Slightly better list presentation.
@@ -1628,11 +1642,17 @@ function M.open_floating_preview(contents, syntax, opts)
   vim.bo[floating_bufnr].modifiable = false
   vim.bo[floating_bufnr].bufhidden = 'wipe'
 
+  if do_stylize then
+    vim.wo[floating_winnr].conceallevel = 2
+    vim.bo[floating_bufnr].filetype = 'markdown'
+    vim.treesitter.start(floating_bufnr)
+  end
+
   return floating_bufnr, floating_winnr
 end
 
 do --[[ References ]]
-  local reference_ns = api.nvim_create_namespace('vim_lsp_references')
+  local reference_ns = api.nvim_create_namespace('nvim.lsp.references')
 
   --- Removes document highlights from a buffer.
   ---
@@ -1645,18 +1665,18 @@ do --[[ References ]]
   ---
   ---@param bufnr integer Buffer id
   ---@param references lsp.DocumentHighlight[] objects to highlight
-  ---@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+  ---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
   ---@see https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
-  function M.buf_highlight_references(bufnr, references, offset_encoding)
+  function M.buf_highlight_references(bufnr, references, position_encoding)
     validate('bufnr', bufnr, 'number', true)
-    validate('offset_encoding', offset_encoding, 'string', false)
+    validate('position_encoding', position_encoding, 'string', false)
     for _, reference in ipairs(references) do
       local range = reference.range
       local start_line = range.start.line
       local end_line = range['end'].line
 
-      local start_idx = get_line_byte_from_position(bufnr, range.start, offset_encoding)
-      local end_idx = get_line_byte_from_position(bufnr, range['end'], offset_encoding)
+      local start_idx = get_line_byte_from_position(bufnr, range.start, position_encoding)
+      local end_idx = get_line_byte_from_position(bufnr, range['end'], position_encoding)
 
       local document_highlight_kind = {
         [protocol.DocumentHighlightKind.Text] = 'LspReferenceText',
@@ -1690,16 +1710,16 @@ end)
 --- |setloclist()|.
 ---
 ---@param locations lsp.Location[]|lsp.LocationLink[]
----@param offset_encoding? 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---                         default to first client of buffer
 ---@return vim.quickfix.entry[] # See |setqflist()| for the format
-function M.locations_to_items(locations, offset_encoding)
-  if offset_encoding == nil then
+function M.locations_to_items(locations, position_encoding)
+  if position_encoding == nil then
     vim.notify_once(
-      'locations_to_items must be called with valid offset encoding',
+      'locations_to_items must be called with valid position encoding',
       vim.log.levels.WARN
     )
-    offset_encoding = vim.lsp.get_clients({ bufnr = 0 })[1].offset_encoding
+    position_encoding = vim.lsp.get_clients({ bufnr = 0 })[1].offset_encoding
   end
 
   local items = {} --- @type vim.quickfix.entry[]
@@ -1736,8 +1756,8 @@ function M.locations_to_items(locations, offset_encoding)
       local end_row = end_pos.line
       local line = lines[row] or ''
       local end_line = lines[end_row] or ''
-      local col = vim.str_byteindex(line, offset_encoding, pos.character, false)
-      local end_col = vim.str_byteindex(end_line, offset_encoding, end_pos.character, false)
+      local col = vim.str_byteindex(line, position_encoding, pos.character, false)
+      local end_col = vim.str_byteindex(end_line, position_encoding, end_pos.character, false)
 
       items[#items + 1] = {
         filename = filename,
@@ -1848,19 +1868,18 @@ function M.try_trim_markdown_code_blocks(lines)
 end
 
 ---@param window integer?: window handle or 0 for current, defaults to current
----@param offset_encoding? 'utf-8'|'utf-16'|'utf-32'? defaults to `offset_encoding` of first client of buffer of `window`
-local function make_position_param(window, offset_encoding)
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
+local function make_position_param(window, position_encoding)
   window = window or 0
   local buf = api.nvim_win_get_buf(window)
   local row, col = unpack(api.nvim_win_get_cursor(window))
-  offset_encoding = offset_encoding or M._get_offset_encoding(buf)
   row = row - 1
   local line = api.nvim_buf_get_lines(buf, row, row + 1, true)[1]
   if not line then
     return { line = 0, character = 0 }
   end
 
-  col = vim.str_utfindex(line, offset_encoding, col, false)
+  col = vim.str_utfindex(line, position_encoding, col, false)
 
   return { line = row, character = col }
 end
@@ -1868,20 +1887,28 @@ end
 --- Creates a `TextDocumentPositionParams` object for the current buffer and cursor position.
 ---
 ---@param window integer?: window handle or 0 for current, defaults to current
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'? defaults to `offset_encoding` of first client of buffer of `window`
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return lsp.TextDocumentPositionParams
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentPositionParams
-function M.make_position_params(window, offset_encoding)
+function M.make_position_params(window, position_encoding)
   window = window or 0
   local buf = api.nvim_win_get_buf(window)
-  offset_encoding = offset_encoding or M._get_offset_encoding(buf)
+  if position_encoding == nil then
+    vim.notify_once(
+      'position_encoding param is required in vim.lsp.util.make_position_params. Defaulting to position encoding of the first client.',
+      vim.log.levels.WARN
+    )
+    --- @diagnostic disable-next-line: deprecated
+    position_encoding = M._get_offset_encoding(buf)
+  end
   return {
     textDocument = M.make_text_document_params(buf),
-    position = make_position_param(window, offset_encoding),
+    position = make_position_param(window, position_encoding),
   }
 end
 
 --- Utility function for getting the encoding of the first LSP client on the given buffer.
+---@deprecated
 ---@param bufnr integer buffer handle or 0 for current, defaults to current
 ---@return string encoding first client if there is one, nil otherwise
 function M._get_offset_encoding(bufnr)
@@ -1904,7 +1931,7 @@ function M._get_offset_encoding(bufnr)
       offset_encoding = this_offset_encoding
     elseif offset_encoding ~= this_offset_encoding then
       vim.notify_once(
-        'warning: multiple different client offset_encodings detected for buffer, this is not supported yet',
+        'warning: multiple different client offset_encodings detected for buffer, vim.lsp.util._get_offset_encoding() uses the offset_encoding from the first client',
         vim.log.levels.WARN
       )
     end
@@ -1919,13 +1946,19 @@ end
 --- `textDocument/rangeFormatting`.
 ---
 ---@param window integer? window handle or 0 for current, defaults to current
----@param offset_encoding "utf-8"|"utf-16"|"utf-32"? defaults to `offset_encoding` of first client of buffer of `window`
----@return table { textDocument = { uri = `current_file_uri` }, range = { start =
----`current_position`, end = `current_position` } }
-function M.make_range_params(window, offset_encoding)
+---@param position_encoding "utf-8"|"utf-16"|"utf-32"
+---@return { textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }
+function M.make_range_params(window, position_encoding)
   local buf = api.nvim_win_get_buf(window or 0)
-  offset_encoding = offset_encoding or M._get_offset_encoding(buf)
-  local position = make_position_param(window, offset_encoding)
+  if position_encoding == nil then
+    vim.notify_once(
+      'position_encoding param is required in vim.lsp.util.make_range_params. Defaulting to position encoding of the first client.',
+      vim.log.levels.WARN
+    )
+    --- @diagnostic disable-next-line: deprecated
+    position_encoding = M._get_offset_encoding(buf)
+  end
+  local position = make_position_param(window, position_encoding)
   return {
     textDocument = M.make_text_document_params(buf),
     range = { start = position, ['end'] = position },
@@ -1940,15 +1973,21 @@ end
 ---@param end_pos [integer,integer]? {row,col} mark-indexed position.
 --- Defaults to the end of the last visual selection.
 ---@param bufnr integer? buffer handle or 0 for current, defaults to current
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'? defaults to `offset_encoding` of first client of `bufnr`
----@return table { textDocument = { uri = `current_file_uri` }, range = { start =
----`start_position`, end = `end_position` } }
-function M.make_given_range_params(start_pos, end_pos, bufnr, offset_encoding)
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
+---@return { textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }
+function M.make_given_range_params(start_pos, end_pos, bufnr, position_encoding)
   validate('start_pos', start_pos, 'table', true)
   validate('end_pos', end_pos, 'table', true)
-  validate('offset_encoding', offset_encoding, 'string', true)
-  bufnr = bufnr or api.nvim_get_current_buf()
-  offset_encoding = offset_encoding or M._get_offset_encoding(bufnr)
+  validate('position_encoding', position_encoding, 'string', true)
+  bufnr = vim._resolve_bufnr(bufnr)
+  if position_encoding == nil then
+    vim.notify_once(
+      'position_encoding param is required in vim.lsp.util.make_given_range_params. Defaulting to position encoding of the first client.',
+      vim.log.levels.WARN
+    )
+    --- @diagnostic disable-next-line: deprecated
+    position_encoding = M._get_offset_encoding(bufnr)
+  end
   --- @type [integer, integer]
   local A = { unpack(start_pos or api.nvim_buf_get_mark(bufnr, '<')) }
   --- @type [integer, integer]
@@ -1956,12 +1995,12 @@ function M.make_given_range_params(start_pos, end_pos, bufnr, offset_encoding)
   -- convert to 0-index
   A[1] = A[1] - 1
   B[1] = B[1] - 1
-  -- account for offset_encoding.
+  -- account for position_encoding.
   if A[2] > 0 then
-    A[2] = M.character_offset(bufnr, A[1], A[2], offset_encoding)
+    A[2] = M.character_offset(bufnr, A[1], A[2], position_encoding)
   end
   if B[2] > 0 then
-    B[2] = M.character_offset(bufnr, B[1], B[2], offset_encoding)
+    B[2] = M.character_offset(bufnr, B[1], B[2], position_encoding)
   end
   -- we need to offset the end character position otherwise we loose the last
   -- character of the selection, as LSP end position is exclusive
@@ -2068,9 +2107,9 @@ end
 ---@param bufnr integer
 ---@param start_line integer
 ---@param end_line integer
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return lsp.Range
-local function make_line_range_params(bufnr, start_line, end_line, offset_encoding)
+local function make_line_range_params(bufnr, start_line, end_line, position_encoding)
   local last_line = api.nvim_buf_line_count(bufnr) - 1
 
   ---@type lsp.Position
@@ -2079,7 +2118,12 @@ local function make_line_range_params(bufnr, start_line, end_line, offset_encodi
   if end_line == last_line and not vim.bo[bufnr].endofline then
     end_pos = {
       line = end_line,
-      character = M.character_offset(bufnr, end_line, #get_line(bufnr, end_line), offset_encoding),
+      character = M.character_offset(
+        bufnr,
+        end_line,
+        #get_line(bufnr, end_line),
+        position_encoding
+      ),
     }
   else
     end_pos = { line = end_line + 1, character = 0 }
@@ -2103,10 +2147,7 @@ end
 ---@param opts? vim.lsp.util._refresh.Opts Options table
 function M._refresh(method, opts)
   opts = opts or {}
-  local bufnr = opts.bufnr
-  if bufnr == nil or bufnr == 0 then
-    bufnr = api.nvim_get_current_buf()
-  end
+  local bufnr = vim._resolve_bufnr(opts.bufnr)
 
   local clients = vim.lsp.get_clients({ bufnr = bufnr, method = method, id = opts.client_id })
 
@@ -2122,7 +2163,12 @@ function M._refresh(method, opts)
         local first = vim.fn.line('w0', window)
         local last = vim.fn.line('w$', window)
         for _, client in ipairs(clients) do
-          client.request(method, {
+          for rid, req in pairs(client.requests) do
+            if req.method == method and req.type == 'pending' and req.bufnr == bufnr then
+              client:cancel_request(rid)
+            end
+          end
+          client:request(method, {
             textDocument = textDocument,
             range = make_line_range_params(bufnr, first - 1, last - 1, client.offset_encoding),
           }, nil, bufnr)
@@ -2131,7 +2177,7 @@ function M._refresh(method, opts)
     end
   else
     for _, client in ipairs(clients) do
-      client.request(method, {
+      client:request(method, {
         textDocument = textDocument,
         range = make_line_range_params(
           bufnr,