feat(lsp)!: change handler signature #15504

11 files changed, 355 insertions, 273 deletions

diff --git a/runtime/doc/lsp.txt b/runtime/doc/lsp.txt
index d6ef761bcb..73e4cbe2ca 100644
--- a/runtime/doc/lsp.txt
+++ b/runtime/doc/lsp.txt
@@ -202,23 +202,28 @@ responses and notifications from LSP servers.
 
 For |lsp-request|, each |lsp-handler| has this signature: >
 
-  function(err, method, result, client_id, bufnr, config)
+  function(err, result, ctx, config)
 <
         Parameters: ~
             {err}       (table|nil)
                             When the language server is unable to complete a
                             request, a table with information about the error
                             is sent. Otherwise, it is `nil`. See |lsp-response|.
-            {method}    (string)
-                            The |lsp-method| name.
             {result}    (Result | Params | nil)
                             When the language server is able to succesfully
                             complete a request, this contains the `result` key
                             of the response. See |lsp-response|.
-            {client_id} (number)
-                            The ID of the |vim.lsp.client|.
-            {bufnr}     (Buffer)
-                            Buffer handle, or 0 for current.
+            {ctx}       (table)
+                            Context describes additional calling state
+                            associated with the handler. It consists of the
+                            following key, value pairs:
+
+                            {method}    (string)
+                                            The |lsp-method| name.
+                            {client_id} (number)
+                                            The ID of the |vim.lsp.client|.
+                            {bufnr}     (Buffer)
+                                           Buffer handle, or 0 for current.
             {config}    (table)
                             Configuration for the handler.
 
@@ -238,21 +243,24 @@ For |lsp-request|, each |lsp-handler| has this signature: >
 
 For |lsp-notification|, each |lsp-handler| has this signature: >
 
-  function(err, method, params, client_id, bufnr, config)
+  function(err, result, ctx, config)
 <
         Parameters: ~
             {err}       (nil)
                             This is always `nil`.
                             See |lsp-notification|
-            {method}    (string)
-                            The |lsp-method| name.
-            {params}    (Params)
+            {result}    (Result)
                             This contains the `params` key of the notification.
                             See |lsp-notification|
-            {client_id} (number)
-                            The ID of the |vim.lsp.client|
-            {bufnr}     (nil)
-                            `nil`, as the server doesn't have an associated buffer.
+            {ctx}       (table)
+                            Context describes additional calling state
+                            associated with the handler. It consists of the
+                            following key, value pairs:
+
+                            {method}    (string)
+                                            The |lsp-method| name.
+                            {client_id} (number)
+                                            The ID of the |vim.lsp.client|.
             {config}    (table)
                             Configuration for the handler.
 
@@ -1355,7 +1363,7 @@ goto_prev({opts})                             *vim.lsp.diagnostic.goto_prev()*
                     {opts}  table See |vim.lsp.diagnostic.goto_next()|
 
                                  *vim.lsp.diagnostic.on_publish_diagnostics()*
-on_publish_diagnostics({_}, {_}, {params}, {client_id}, {_}, {config})
+on_publish_diagnostics({_}, {result}, {ctx}, {config})
                 |lsp-handler| for the method "textDocument/publishDiagnostics"
 
                 Note:
@@ -1581,7 +1589,7 @@ get({bufnr})                                          *vim.lsp.codelens.get()*
                     table ( `CodeLens[]` )
 
                                               *vim.lsp.codelens.on_codelens()*
-on_codelens({err}, {_}, {result}, {client_id}, {bufnr})
+on_codelens({err}, {result}, {ctx}, {_})
                 |lsp-handler| for the method `textDocument/codeLens`
 
 refresh()                                         *vim.lsp.codelens.refresh()*
@@ -1614,17 +1622,25 @@ progress_handler({_}, {_}, {params}, {client_id})
                 See also: ~
                     https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_executeCommand
 
-                                           *vim.lsp.handlers.signature_help()*
-signature_help({_}, {method}, {result}, {_}, {bufnr}, {config})
-                Parameters: ~
-                    {config}  table Configuration table.
-                              • border: (default=nil)
-                                • Add borders to the floating window
-                                • See |vim.api.nvim_open_win()|
+hover({_}, {result}, {ctx}, {config})               *vim.lsp.handlers.hover()*
+                |lsp-handler| for the method "textDocument/hover" >
 
+                 vim.lsp.handlers["textDocument/hover"] = vim.lsp.with(
+                   vim.lsp.handlers.hover, {
+                     -- Use a sharp border with `FloatBorder` highlights
+                     border = "single"
+                   }
+                 )
+<
                 See also: ~
                     https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_declaration@seehttps://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_definition@seehttps://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_typeDefinition@seehttps://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_implementation|lsp-handler| for the method "textDocument/signatureHelp">
 
+                                           *vim.lsp.handlers.signature_help()*
+signature_help({_}, {result}, {ctx}, {config})
+                |lsp-handler| for the method "textDocument/signatureHelp". The
+                active parameter is highlighted with
+                |hl-LspSignatureActiveParameter|. >
+
                  vim.lsp.handlers["textDocument/signatureHelp"] = vim.lsp.with(
                    vim.lsp.handlers.signature_help, {
                      -- Use a sharp border with `FloatBorder` highlights
diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index 16d2fcd424..f29b7a1241 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -1474,14 +1474,12 @@ validate({opt})                                               *vim.validate()*
 
                   vim.validate{arg1={{'foo'}, 'table'}, arg2={'foo', 'string'}}
                      => NOP (success)
-<
->
-    vim.validate{arg1={1, 'table'}}
-       => error('arg1: expected table, got number')
-<
->
-    vim.validate{arg1={3, function(a) return (a % 2) == 0 end, 'even number'}}
-       => error('arg1: expected even number, got 3')
+
+                  vim.validate{arg1={1, 'table'}}
+                     => error('arg1: expected table, got number')
+
+                  vim.validate{arg1={3, function(a) return (a % 2) == 0 end, 'even number'}}
+                     => error('arg1: expected even number, got 3')
 <
 
                 Parameters: ~
diff --git a/runtime/doc/treesitter.txt b/runtime/doc/treesitter.txt
index 416ea3a08a..eccdc3df15 100644
--- a/runtime/doc/treesitter.txt
+++ b/runtime/doc/treesitter.txt
@@ -474,11 +474,9 @@ Query:iter_matches({self}, {node}, {source}, {start}, {stop})
       for id, node in pairs(match) do
         local name = query.captures[id]
         -- `node` was captured by the `name` capture in the match
-<
->
-    local node_data = metadata[id] -- Node level metadata
-<
->
+
+        local node_data = metadata[id] -- Node level metadata
+
         ... use the info here ...
       end
     end
diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index 6575e453da..6365091668 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/runtime/lua/vim/lsp.lua
@@ -681,7 +681,7 @@ function lsp.start_client(config)
     local handler = resolve_handler(method)
     if handler then
       -- Method name is provided here for convenience.
-      handler(nil, method, params, client_id)
+      handler(nil, params, {method=method, client_id=client_id})
     end
   end
 
@@ -695,7 +695,7 @@ function lsp.start_client(config)
     local handler = resolve_handler(method)
     if handler then
       local _ = log.debug() and log.debug("server_request: found handler for", method)
-      return handler(nil, method, params, client_id)
+      return handler(nil, params, {method=method, client_id=client_id})
     end
     local _ = log.debug() and log.debug("server_request: no handler found for", method)
     return nil, lsp.rpc_response_error(protocol.ErrorCodes.MethodNotFound)
@@ -894,7 +894,7 @@ function lsp.start_client(config)
 
     local _ = log.debug() and log.debug(log_prefix, "client.request", client_id, method, params, handler, bufnr)
     return rpc.request(method, params, function(err, result)
-      handler(err, method, result, client_id, bufnr)
+      handler(err, result, {method=method, client_id=client_id, bufnr=bufnr})
     end)
   end
 
@@ -915,7 +915,7 @@ function lsp.start_client(config)
   --@see |vim.lsp.buf_request_sync()|
   function client.request_sync(method, params, timeout_ms, bufnr)
     local request_result = nil
-    local function _sync_handler(err, _, result)
+    local function _sync_handler(err, result)
       request_result = { err = err, result = result }
     end
 
@@ -1274,7 +1274,7 @@ function lsp.buf_request(bufnr, method, params, handler)
     local unsupported_err = lsp._unsupported_method(method)
     handler = handler or lsp.handlers[method]
     if handler then
-      handler(unsupported_err, method, bufnr)
+      handler(unsupported_err, nil, {method=method, bufnr=bufnr})
     end
     return
   end
@@ -1314,8 +1314,8 @@ function lsp.buf_request_all(bufnr, method, params, callback)
     end
   end)
 
-  local function _sync_handler(err, _, result, client_id)
-    request_results[client_id] = { error = err, result = result }
+  local function _sync_handler(err, result, ctx)
+    request_results[ctx.client_id] = { error = err, result = result }
     result_count = result_count + 1
     set_expected_result_count()
 
@@ -1421,7 +1421,7 @@ function lsp.omnifunc(findstart, base)
   local params = util.make_position_params()
 
   local items = {}
-  lsp.buf_request(bufnr, 'textDocument/completion', params, function(err, _, result)
+  lsp.buf_request(bufnr, 'textDocument/completion', params, function(err, result)
     if err or not result or vim.fn.mode() ~= "i" then return end
     local matches = util.text_document_completion_list_to_complete_items(result, prefix)
     -- TODO(ashkan): is this the best way to do this?
@@ -1496,8 +1496,8 @@ end
 --@param handler (function) See |lsp-handler|
 --@param override_config (table) Table containing the keys to override behavior of the {handler}
 function lsp.with(handler, override_config)
-  return function(err, method, params, client_id, bufnr, config)
-    return handler(err, method, params, client_id, bufnr, vim.tbl_deep_extend("force", config or {}, override_config))
+  return function(err, result, ctx, config)
+    return handler(err, result, ctx, vim.tbl_deep_extend("force", config or {}, override_config))
   end
 end
 
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index b13d662ccb..8dfd5c9c5b 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -422,6 +422,21 @@ function M.clear_references()
   util.buf_clear_references()
 end
 
+--- Requests code actions from all clients and calls the handler exactly once
+--- with all aggregated results
+---@private
+local function code_action_request(params)
+  local bufnr = vim.api.nvim_get_current_buf()
+  local method = 'textDocument/codeAction'
+  vim.lsp.buf_request_all(bufnr, method, params, function(results)
+    local actions = {}
+    for _, r in pairs(results) do
+      vim.list_extend(actions, r.result or {})
+    end
+    vim.lsp.handlers[method](nil, actions, {bufnr=bufnr, method=method})
+  end)
+end
+
 --- Selects a code action from the input list that is available at the current
 --- cursor position.
 --
diff --git a/runtime/lua/vim/lsp/codelens.lua b/runtime/lua/vim/lsp/codelens.lua
index fbd37e3830..6655a0ada0 100644
--- a/runtime/lua/vim/lsp/codelens.lua
+++ b/runtime/lua/vim/lsp/codelens.lua
@@ -192,17 +192,17 @@ end
 
 --- |lsp-handler| for the method `textDocument/codeLens`
 ---
-function M.on_codelens(err, _, result, client_id, bufnr)
+function M.on_codelens(err, result, ctx, _)
   assert(not err, vim.inspect(err))
 
-  M.save(result, bufnr, client_id)
+  M.save(result, ctx.bufnr, ctx.client_id)
 
   -- Eager display for any resolved (and unresolved) lenses and refresh them
   -- once resolved.
-  M.display(result, bufnr, client_id)
-  resolve_lenses(result, bufnr, client_id, function()
-    M.display(result, bufnr, client_id)
-    active_refreshes[bufnr] = nil
+  M.display(result, ctx.bufnr, ctx.client_id)
+  resolve_lenses(result, ctx.bufnr, ctx.client_id, function()
+    M.display(result, ctx.bufnr, ctx.client_id)
+    active_refreshes[ctx.bufnr] = nil
   end)
 end
 
diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index c83e29aa64..01a75d4094 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -1008,15 +1008,16 @@ end
 ---         - Update diagnostics in InsertMode or wait until InsertLeave
 ---     - severity_sort:    (default=false)
 ---         - Sort diagnostics (and thus signs and virtual text)
-function M.on_publish_diagnostics(_, _, params, client_id, _, config)
-  local uri = params.uri
+function M.on_publish_diagnostics(_, result, ctx, config)
+  local client_id = ctx.client_id
+  local uri = result.uri
   local bufnr = vim.uri_to_bufnr(uri)
 
   if not bufnr then
     return
   end
 
-  local diagnostics = params.diagnostics
+  local diagnostics = result.diagnostics
 
   if config and if_nil(config.severity_sort, false) then
     table.sort(diagnostics, function(a, b) return a.severity > b.severity end)
@@ -1164,8 +1165,41 @@ function M.display(diagnostics, bufnr, client_id, config)
   save_extmarks(bufnr, client_id)
 end
 
--- }}}
--- Diagnostic User Functions {{{
+--- Redraw diagnostics for the given buffer and client
+---
+--- This calls the "textDocument/publishDiagnostics" handler manually using
+--- the cached diagnostics already received from the server. This can be useful
+--- for redrawing diagnostics after making changes in diagnostics
+--- configuration. |lsp-handler-configuration|
+---
+---@param bufnr (optional, number): Buffer handle, defaults to current
+---@param client_id (optional, number): Redraw diagnostics for the given
+---       client. The default is to redraw diagnostics for all attached
+---       clients.
+function M.redraw(bufnr, client_id)
+  bufnr = get_bufnr(bufnr)
+  if not client_id then
+    return vim.lsp.for_each_buffer_client(bufnr, function(client)
+      M.redraw(bufnr, client.id)
+    end)
+  end
+
+  -- We need to invoke the publishDiagnostics handler directly instead of just
+  -- calling M.display so that we can preserve any custom configuration options
+  -- the user may have set with vim.lsp.with.
+  vim.lsp.handlers["textDocument/publishDiagnostics"](
+    nil,
+    {
+      uri = vim.uri_from_bufnr(bufnr),
+      diagnostics = M.get(bufnr, client_id),
+    },
+    {
+      method = "textDocument/publishDiagnostics",
+      client_id = client_id,
+      bufnr = bufnr,
+    }
+    )
+  end
 
 --- Open a floating window with the diagnostics from {line_nr}
 ---
diff --git a/runtime/lua/vim/lsp/handlers.lua b/runtime/lua/vim/lsp/handlers.lua
index 0c0aa0ceb6..15a5665893 100644
--- a/runtime/lua/vim/lsp/handlers.lua
+++ b/runtime/lua/vim/lsp/handlers.lua
@@ -17,21 +17,21 @@ local function err_message(...)
   api.nvim_command("redraw")
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_executeCommand
-M['workspace/executeCommand'] = function()
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_executeCommand
+M['workspace/executeCommand'] = function(_, _, _, _)
   -- Error handling is done implicitly by wrapping all handlers; see end of this file
 end
 
--- @msg of type ProgressParams
--- Basically a token of type number/string
-local function progress_handler(_, _, params, client_id)
+---@private
+local function progress_handler(_, result, ctx, _)
+  local client_id = ctx.client_id
   local client = vim.lsp.get_client_by_id(client_id)
   local client_name = client and client.name or string.format("id=%d", client_id)
   if not client then
     err_message("LSP[", client_name, "] client has shut down after sending the message")
   end
-  local val = params.value    -- unspecified yet
-  local token = params.token  -- string or number
+  local val = result.value    -- unspecified yet
+  local token = result.token  -- string or number
 
 
   if val.kind then
@@ -62,10 +62,11 @@ end
 --@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#progress
 M['$/progress'] = progress_handler
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_workDoneProgress_create
-M['window/workDoneProgress/create'] =  function(_, _, params, client_id)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_workDoneProgress_create
+M['window/workDoneProgress/create'] =  function(_, result, ctx)
+  local client_id = ctx.client_id
   local client = vim.lsp.get_client_by_id(client_id)
-  local token = params.token  -- string or number
+  local token = result.token  -- string or number
   local client_name = client and client.name or string.format("id=%d", client_id)
   if not client then
     err_message("LSP[", client_name, "] client has shut down after sending the message")
@@ -74,12 +75,12 @@ M['window/workDoneProgress/create'] =  function(_, _, params, client_id)
   return vim.NIL
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_showMessageRequest
-M['window/showMessageRequest'] = function(_, _, params)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_showMessageRequest
+M['window/showMessageRequest'] = function(_, result)
 
-  local actions = params.actions
-  print(params.message)
-  local option_strings = {params.message, "\nRequest Actions:"}
+  local actions = result.actions
+  print(result.message)
+  local option_strings = {result.message, "\nRequest Actions:"}
   for i, action in ipairs(actions) do
     local title = action.title:gsub('\r\n', '\\r\\n')
     title = title:gsub('\n', '\\n')
@@ -95,8 +96,9 @@ M['window/showMessageRequest'] = function(_, _, params)
   end
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#client_registerCapability
-M['client/registerCapability'] = function(_, _, _, client_id)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#client_registerCapability
+M['client/registerCapability'] = function(_, _, ctx)
+  local client_id = ctx.client_id
   local warning_tpl = "The language server %s triggers a registerCapability "..
                       "handler despite dynamicRegistration set to false. "..
                       "Report upstream, this warning is harmless"
@@ -107,25 +109,25 @@ M['client/registerCapability'] = function(_, _, _, client_id)
   return vim.NIL
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_codeAction
-M['textDocument/codeAction'] = function(_, _, actions)
-  if actions == nil or vim.tbl_isempty(actions) then
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_codeAction
+M['textDocument/codeAction'] = function(_, result)
+  if result == nil or vim.tbl_isempty(result) then
     print("No code actions available")
     return
   end
 
-  local option_strings = {"Code Actions:"}
-  for i, action in ipairs(actions) do
+  local option_strings = {"Code actions:"}
+  for i, action in ipairs(result) do
     local title = action.title:gsub('\r\n', '\\r\\n')
     title = title:gsub('\n', '\\n')
     table.insert(option_strings, string.format("%d. %s", i, title))
   end
 
   local choice = vim.fn.inputlist(option_strings)
-  if choice < 1 or choice > #actions then
+  if choice < 1 or choice > #result then
     return
   end
-  local action_chosen = actions[choice]
+  local action_chosen = result[choice]
   -- textDocument/codeAction can return either Command[] or CodeAction[].
   -- If it is a CodeAction, it can have either an edit, a command or both.
   -- Edits should be executed first
@@ -155,29 +157,30 @@ M['workspace/applyEdit'] = function(_, _, workspace_edit)
   }
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_configuration
-M['workspace/configuration'] = function(_, _, params, client_id)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_configuration
+M['workspace/configuration'] = function(_, result, ctx)
+  local client_id = ctx.client_id
   local client = vim.lsp.get_client_by_id(client_id)
   if not client then
     err_message("LSP[id=", client_id, "] client has shut down after sending the message")
     return
   end
-  if not params.items then
+  if not result.items then
     return {}
   end
 
-  local result = {}
-  for _, item in ipairs(params.items) do
+  local response = {}
+  for _, item in ipairs(result.items) do
     if item.section then
       local value = util.lookup_section(client.config.settings, item.section) or vim.NIL
       -- For empty sections with no explicit '' key, return settings as is
       if value == vim.NIL and item.section == '' then
         value = client.config.settings or vim.NIL
       end
-      table.insert(result, value)
+      table.insert(response, value)
     end
   end
-  return result
+  return response
 end
 
 M['textDocument/publishDiagnostics'] = function(...)
@@ -190,52 +193,63 @@ end
 
 
 
---@private
---- Return a function that converts LSP responses to quickfix items and opens the qflist
---
---@param map_result function `((resp, bufnr) -> list)` to convert the response
---@param entity name of the resource used in a `not found` error message
-local function response_to_qflist(map_result, entity)
-  return function(_, _, result, _, bufnr)
+---@private
+--- Return a function that converts LSP responses to list items and opens the list
+---
+--- The returned function has an optional {config} parameter that accepts a table
+--- with the following keys:
+---
+---   loclist: (boolean) use the location list (default is to use the quickfix list)
+---
+---@param map_result function `((resp, bufnr) -> list)` to convert the response
+---@param entity name of the resource used in a `not found` error message
+local function response_to_list(map_result, entity)
+  return function(_,result, ctx, config)
     if not result or vim.tbl_isempty(result) then
       vim.notify('No ' .. entity .. ' found')
     else
-      util.set_qflist(map_result(result, bufnr))
-      api.nvim_command("copen")
+      config = config or {}
+      if config.loclist then
+        util.set_loclist(map_result(result, ctx.bufnr))
+        api.nvim_command("lopen")
+      else
+        util.set_qflist(map_result(result, ctx.bufnr))
+        api.nvim_command("copen")
+      end
     end
   end
 end
 
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_references
-M['textDocument/references'] = response_to_qflist(util.locations_to_items, 'references')
+ --see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_references
+M['textDocument/references'] = response_to_list(util.locations_to_items, 'references')
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentSymbol
-M['textDocument/documentSymbol'] = response_to_qflist(util.symbols_to_items, 'document symbols')
+ --see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentSymbol
+M['textDocument/documentSymbol'] = response_to_list(util.symbols_to_items, 'document symbols')
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_symbol
-M['workspace/symbol'] = response_to_qflist(util.symbols_to_items, 'symbols')
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_symbol
+M['workspace/symbol'] = response_to_list(util.symbols_to_items, 'symbols')
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rename
-M['textDocument/rename'] = function(_, _, result)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rename
+M['textDocument/rename'] = function(_, result, _)
   if not result then return end
   util.apply_workspace_edit(result)
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rangeFormatting
-M['textDocument/rangeFormatting'] = function(_, _, result)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_rangeFormatting
+M['textDocument/rangeFormatting'] = function(_, result, ctx, _)
   if not result then return end
-  util.apply_text_edits(result)
+  util.apply_text_edits(result, ctx.bufnr)
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_formatting
-M['textDocument/formatting'] = function(_, _, result)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_formatting
+M['textDocument/formatting'] = function(_, result, ctx, _)
   if not result then return end
-  util.apply_text_edits(result)
+  util.apply_text_edits(result, ctx.bufnr)
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion
-M['textDocument/completion'] = function(_, _, result)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion
+M['textDocument/completion'] = function(_, result, _, _)
   if vim.tbl_isempty(result or {}) then return end
   local row, col = unpack(api.nvim_win_get_cursor(0))
   local line = assert(api.nvim_buf_get_lines(0, row-1, row, false)[1])
@@ -260,9 +274,9 @@ end
 ---     - border:     (default=nil)
 ---         - Add borders to the floating window
 ---         - See |vim.api.nvim_open_win()|
-function M.hover(_, method, result, _, _, config)
+function M.hover(_, result, ctx, config)
   config = config or {}
-  config.focus_id = method
+  config.focus_id = ctx.method
   if not (result and result.contents) then
     -- return { 'No information available' }
     return
@@ -281,13 +295,13 @@ M['textDocument/hover'] = M.hover
 
 --@private
 --- Jumps to a location. Used as a handler for multiple LSP methods.
---@param _ (not used)
---@param method (string) LSP method name
---@param result (table) result of LSP method; a location or a list of locations.
+---@param _ (not used)
+---@param result (table) result of LSP method; a location or a list of locations.
+---@param ctx (table) table containing the context of the request, including the method
 ---(`textDocument/definition` can return `Location` or `Location[]`
-local function location_handler(_, method, result)
+local function location_handler(_, result, ctx, _)
   if result == nil or vim.tbl_isempty(result) then
-    local _ = log.info() and log.info(method, 'No location found')
+    local _ = log.info() and log.info(ctx.method, 'No location found')
     return nil
   end
 
@@ -328,17 +342,19 @@ M['textDocument/implementation'] = location_handler
 ---     - border:     (default=nil)
 ---         - Add borders to the floating window
 ---         - See |vim.api.nvim_open_win()|
-function M.signature_help(_, method, result, _, bufnr, config)
+function M.signature_help(_, result, ctx, config)
   config = config or {}
-  config.focus_id = method
+  config.focus_id = ctx.method
   -- When use `autocmd CompleteDone <silent><buffer> lua vim.lsp.buf.signature_help()` to call signatureHelp handler
   -- If the completion item doesn't have signatures It will make noise. Change to use `print` that can use `<silent>` to ignore
   if not (result and result.signatures and result.signatures[1]) then
     print('No signature help available')
     return
   end
-  local ft = api.nvim_buf_get_option(bufnr, 'filetype')
-  local lines = util.convert_signature_help_to_markdown_lines(result, ft)
+  local client = vim.lsp.get_client_by_id(ctx.client_id)
+  local triggers = client.resolved_capabilities.signature_help_trigger_characters
+  local ft = api.nvim_buf_get_option(ctx.bufnr, 'filetype')
+  local lines, hl = util.convert_signature_help_to_markdown_lines(result, ft, triggers)
   lines = util.trim_empty_lines(lines)
   if vim.tbl_isempty(lines) then
     print('No signature help available')
@@ -350,10 +366,10 @@ end
 --@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_signatureHelp
 M['textDocument/signatureHelp'] = M.signature_help
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentHighlight
-M['textDocument/documentHighlight'] = function(_, _, result, _, bufnr, _)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentHighlight
+M['textDocument/documentHighlight'] = function(_, result, ctx, _)
   if not result then return end
-  util.buf_highlight_references(bufnr, result)
+  util.buf_highlight_references(ctx.bufnr, result)
 end
 
 --@private
@@ -364,7 +380,7 @@ end
 --@returns `CallHierarchyIncomingCall[]` if {direction} is `"from"`,
 --@returns `CallHierarchyOutgoingCall[]` if {direction} is `"to"`,
 local make_call_hierarchy_handler = function(direction)
-  return function(_, _, result)
+  return function(_, result)
     if not result then return end
     local items = {}
     for _, call_hierarchy_call in pairs(result) do
@@ -389,10 +405,11 @@ M['callHierarchy/incomingCalls'] = make_call_hierarchy_handler('from')
 --@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#callHierarchy/outgoingCalls
 M['callHierarchy/outgoingCalls'] = make_call_hierarchy_handler('to')
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window/logMessage
-M['window/logMessage'] = function(_, _, result, client_id)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_logMessage
+M['window/logMessage'] = function(_, result, ctx, _)
   local message_type = result.type
   local message = result.message
+  local client_id = ctx.client_id
   local client = vim.lsp.get_client_by_id(client_id)
   local client_name = client and client.name or string.format("id=%d", client_id)
   if not client then
@@ -410,10 +427,11 @@ M['window/logMessage'] = function(_, _, result, client_id)
   return result
 end
 
---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window/showMessage
-M['window/showMessage'] = function(_, _, result, client_id)
+--see: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#window_showMessage
+M['window/showMessage'] = function(_, result, ctx, _)
   local message_type = result.type
   local message = result.message
+  local client_id = ctx.client_id
   local client = vim.lsp.get_client_by_id(client_id)
   local client_name = client and client.name or string.format("id=%d", client_id)
   if not client then
@@ -430,12 +448,14 @@ end
 
 -- Add boilerplate error validation and logging for all of these.
 for k, fn in pairs(M) do
-  M[k] = function(err, method, params, client_id, bufnr, config)
-    local _ = log.debug() and log.debug('default_handler', method, {
-      params = params, client_id = client_id, err = err, bufnr = bufnr, config = config
+  M[k] = function(err, result, ctx, config)
+    local _ = log.debug() and log.debug('default_handler', ctx.method, {
+      err = err, result = result, ctx=vim.inspect(ctx), config = config
     })
 
     if err then
+      local client = vim.lsp.get_client_by_id(ctx.client_id)
+      local client_name = client and client.name or string.format("client_id=%d", ctx.client_id)
       -- LSP spec:
       -- interface ResponseError:
       --  code: integer;
@@ -444,7 +464,7 @@ for k, fn in pairs(M) do
       return err_message(tostring(err.code) .. ': ' .. err.message)
     end
 
-    return fn(err, method, params, client_id, bufnr, config)
+    return fn(err, result, ctx, config)
   end
 end
 
diff --git a/test/functional/plugin/lsp/codelens_spec.lua b/test/functional/plugin/lsp/codelens_spec.lua
index e09d93f7cc..ac201e574c 100644
--- a/test/functional/plugin/lsp/codelens_spec.lua
+++ b/test/functional/plugin/lsp/codelens_spec.lua
@@ -32,7 +32,7 @@ describe('vim.lsp.codelens', function()
           command = { title = 'Lens1', command = 'Dummy' }
         },
       }
-      vim.lsp.codelens.on_codelens(nil, 'textDocument/codeLens', lenses, 1, bufnr)
+      vim.lsp.codelens.on_codelens(nil, lenses, {method='textDocument/codeLens', client_id=1, bufnr=bufnr})
     ]], bufnr)
 
     local stored_lenses = exec_lua('return vim.lsp.codelens.get(...)', bufnr)
diff --git a/test/functional/plugin/lsp/diagnostic_spec.lua b/test/functional/plugin/lsp/diagnostic_spec.lua
index 962028e7e1..1814ce8ec1 100644
--- a/test/functional/plugin/lsp/diagnostic_spec.lua
+++ b/test/functional/plugin/lsp/diagnostic_spec.lua
@@ -205,8 +205,8 @@ describe('vim.lsp.diagnostic', function()
             make_warning("Warning 1", 2, 1, 2, 5),
           }
 
-          vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, { uri = fake_uri, diagnostics = server_1_diags }, 1)
-          vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, { uri = fake_uri, diagnostics = server_2_diags }, 2)
+          vim.lsp.diagnostic.on_publish_diagnostics(nil, { uri = fake_uri, diagnostics = server_1_diags }, {client_id=1})
+          vim.lsp.diagnostic.on_publish_diagnostics(nil, { uri = fake_uri, diagnostics = server_2_diags }, {client_id=2})
           return {
             vim.lsp.diagnostic.get_count(diagnostic_bufnr, "Error", 1),
             vim.lsp.diagnostic.get_count(diagnostic_bufnr, "Warning", 2),
@@ -258,8 +258,8 @@ describe('vim.lsp.diagnostic', function()
               make_warning("Warning 1", 2, 1, 2, 5),
             }
 
-            vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, { uri = fake_uri, diagnostics = server_1_diags }, 1)
-            vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, { uri = fake_uri, diagnostics = server_2_diags }, 2)
+            vim.lsp.diagnostic.on_publish_diagnostics(nil, { uri = fake_uri, diagnostics = server_1_diags }, {client_id=1})
+            vim.lsp.diagnostic.on_publish_diagnostics(nil, { uri = fake_uri, diagnostics = server_2_diags }, {client_id=2})
             return {
               vim.lsp.diagnostic.get_count(diagnostic_bufnr, "Error", 1),
               vim.lsp.diagnostic.get_count(diagnostic_bufnr, "Warning", 2),
@@ -435,14 +435,14 @@ describe('vim.lsp.diagnostic', function()
 
     it('should return all diagnostics when no severity is supplied', function()
       eq(2, exec_lua [[
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
           uri = fake_uri,
           diagnostics = {
             make_error("Error 1", 1, 1, 1, 5),
             make_warning("Warning on Server 1", 1, 1, 2, 5),
             make_error("Error On Other Line", 2, 1, 1, 5),
           }
-        }, 1)
+        }, {client_id=1})
 
         return #vim.lsp.diagnostic.get_line_diagnostics(diagnostic_bufnr, 1)
       ]])
@@ -450,7 +450,7 @@ describe('vim.lsp.diagnostic', function()
 
     it('should return only requested diagnostics when severity_limit is supplied', function()
       eq(2, exec_lua [[
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
           uri = fake_uri,
           diagnostics = {
             make_error("Error 1", 1, 1, 1, 5),
@@ -458,7 +458,7 @@ describe('vim.lsp.diagnostic', function()
             make_information("Ignored information", 1, 1, 2, 5),
             make_error("Error On Other Line", 2, 1, 1, 5),
           }
-        }, 1)
+        }, {client_id=1})
 
         return #vim.lsp.diagnostic.get_line_diagnostics(diagnostic_bufnr, 1, { severity_limit = "Warning" })
       ]])
@@ -470,12 +470,12 @@ describe('vim.lsp.diagnostic', function()
       exec_lua [[
         vim.lsp.with(vim.lsp.diagnostic.on_publish_diagnostics, {
           virtual_text = function() return true end,
-        })(nil, nil, {
+        })(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -487,12 +487,12 @@ describe('vim.lsp.diagnostic', function()
       exec_lua [[
         vim.lsp.with(vim.lsp.diagnostic.on_publish_diagnostics, {
           virtual_text = function() return false end,
-        })(nil, nil, {
+        })(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -509,12 +509,12 @@ describe('vim.lsp.diagnostic', function()
       exec_lua [[
         vim.lsp.with(vim.lsp.diagnostic.on_publish_diagnostics, {
           update_in_insert = false,
-        })(nil, nil, {
+        })(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -551,12 +551,12 @@ describe('vim.lsp.diagnostic', function()
           return SetVirtualTextOriginal(...)
         end
 
-        PublishDiagnostics(nil, nil, {
+        PublishDiagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -605,12 +605,12 @@ describe('vim.lsp.diagnostic', function()
           return SetVirtualTextOriginal(...)
         end
 
-        PublishDiagnostics(nil, nil, {
+        PublishDiagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -647,12 +647,12 @@ describe('vim.lsp.diagnostic', function()
       exec_lua [[
         vim.lsp.with(vim.lsp.diagnostic.on_publish_diagnostics, {
           update_in_insert = true,
-        })(nil, nil, {
+        })(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
       ]]
 
@@ -677,12 +677,12 @@ describe('vim.lsp.diagnostic', function()
           },
         })
 
-        PublishDiagnostics(nil, nil, {
+        PublishDiagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
 
         return vim.api.nvim_buf_get_extmarks(
@@ -714,12 +714,12 @@ describe('vim.lsp.diagnostic', function()
           end,
         })
 
-        PublishDiagnostics(nil, nil, {
+        PublishDiagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Delayed Diagnostic', 4, 4, 4, 4),
             }
-          }, 1
+          }, {client_id=1}
         )
 
         return vim.api.nvim_buf_get_extmarks(
@@ -747,12 +747,12 @@ describe('vim.lsp.diagnostic', function()
             },
           })
 
-          PublishDiagnostics(nil, nil, {
+          PublishDiagnostics(nil, {
               uri = fake_uri,
               diagnostics = {
                 make_warning('Delayed Diagnostic', 4, 4, 4, 4),
               }
-            }, 1
+            }, {client_id=1}
           )
 
           return count_of_extmarks_for_client(diagnostic_bufnr, 1)
@@ -838,10 +838,10 @@ describe('vim.lsp.diagnostic', function()
         }
 
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
             uri = fake_uri,
             diagnostics = diagnostics
-          }, 1
+          }, {client_id=1}
         )
 
         vim.lsp.diagnostic.set_signs(diagnostics, diagnostic_bufnr, 1)
@@ -863,13 +863,13 @@ describe('vim.lsp.diagnostic', function()
       local loc_list = exec_lua [[
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
 
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Farther Diagnostic', 4, 4, 4, 4),
               make_error('Lower Diagnostic', 1, 1, 1, 1),
             }
-          }, 1
+          }, {client_id=1}
         )
 
         vim.lsp.diagnostic.set_loclist()
@@ -884,20 +884,20 @@ describe('vim.lsp.diagnostic', function()
       local loc_list = exec_lua [[
         vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
 
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_error('Lower Diagnostic', 1, 1, 1, 1),
             }
-          }, 1
+          }, {client_id=1}
         )
 
-        vim.lsp.diagnostic.on_publish_diagnostics(nil, nil, {
+        vim.lsp.diagnostic.on_publish_diagnostics(nil, {
             uri = fake_uri,
             diagnostics = {
               make_warning('Farther Diagnostic', 4, 4, 4, 4),
             }
-          }, 2
+          }, {client_id=2}
         )
 
         vim.lsp.diagnostic.set_loclist()
diff --git a/test/functional/plugin/lsp_spec.lua b/test/functional/plugin/lsp_spec.lua
index d1a34e8d9b..da96ff6a5f 100644
--- a/test/functional/plugin/lsp_spec.lua
+++ b/test/functional/plugin/lsp_spec.lua
@@ -216,7 +216,7 @@ describe('LSP', function()
 
     it('should run correctly', function()
       local expected_handlers = {
-        {NIL, "test", {}, 1};
+        {NIL, {}, {method="test", client_id=1}};
       }
       test_rpc_server {
         test_name = "basic_init";
@@ -241,7 +241,7 @@ describe('LSP', function()
 
     it('should fail', function()
       local expected_handlers = {
-        {NIL, "test", {}, 1};
+        {NIL, {}, {method="test", client_id=1}};
       }
       test_rpc_server {
         test_name = "basic_init";
@@ -269,8 +269,8 @@ describe('LSP', function()
         return
       end
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1, NIL};
-        {NIL, "test", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="test", client_id=1}};
       }
       test_rpc_server {
         test_name = "basic_init";
@@ -292,12 +292,12 @@ describe('LSP', function()
 
     it('client should return settings via workspace/configuration handler', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "workspace/configuration", { items = {
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, { items = {
               { section = "testSetting1" };
               { section = "testSetting2" };
-          }}, 1};
-        {NIL, "start", {}, 1};
+          }}, { method="workspace/configuration", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -309,9 +309,9 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'start' then
             exec_lua([=[
               local client = vim.lsp.get_client_by_id(TEST_RPC_CLIENT_ID)
               client.config.settings = {
@@ -319,13 +319,13 @@ describe('LSP', function()
                 testSetting2 = false;
             }]=])
           end
-          if method == 'workspace/configuration' then
-            local result = exec_lua([=[
+          if ctx.method == 'workspace/configuration' then
+            local server_result = exec_lua([=[
               local method, params = ...
-              return require'vim.lsp.handlers'['workspace/configuration'](err, method, params, TEST_RPC_CLIENT_ID)]=], method, params)
-            client.notify('workspace/configuration', result)
+              return require'vim.lsp.handlers'['workspace/configuration'](err, params, {method=method, client_id=TEST_RPC_CLIENT_ID})]=], ctx.method, result)
+            client.notify('workspace/configuration', server_result)
           end
-          if method == 'shutdown' then
+          if ctx.method == 'shutdown' then
             client.stop()
           end
         end;
@@ -335,19 +335,19 @@ describe('LSP', function()
       clear_notrace()
       fake_lsp_server_setup('workspace/configuration no settings')
       eq({ NIL, NIL, }, exec_lua [[
-        local params = {
+        local result = {
           items = {
             {section = 'foo'},
             {section = 'bar'},
           }
         }
-        return vim.lsp.handlers['workspace/configuration'](nil, nil, params, TEST_RPC_CLIENT_ID)
+        return vim.lsp.handlers['workspace/configuration'](nil, result, {client_id=TEST_RPC_CLIENT_ID})
       ]])
     end)
 
     it('should verify capabilities sent', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
       }
       test_rpc_server {
         test_name = "basic_check_capabilities";
@@ -371,7 +371,7 @@ describe('LSP', function()
 
     it('client.supports_methods() should validate capabilities', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
       }
       test_rpc_server {
         test_name = "capabilities_for_client_supports_method";
@@ -405,7 +405,7 @@ describe('LSP', function()
 
     it('should call unsupported_method when trying to call an unsupported method', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
       }
       test_rpc_server {
         test_name = "capabilities_for_client_supports_method";
@@ -413,7 +413,8 @@ describe('LSP', function()
             exec_lua([=[
               BUFFER = vim.api.nvim_get_current_buf()
               lsp.buf_attach_client(BUFFER, TEST_RPC_CLIENT_ID)
-              vim.lsp.handlers['textDocument/typeDefinition'] = function(err, method)
+              vim.lsp.handlers['textDocument/typeDefinition'] = function(err, result, ctx)
+                local method = ctx.method
                 vim.lsp._last_lsp_handler = { err = err; method = method }
               end
               vim.lsp._unsupported_method = function(method)
@@ -446,7 +447,7 @@ describe('LSP', function()
 
     it('shouldn\'t call unsupported_method when no client and trying to call an unsupported method', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
       }
       test_rpc_server {
         test_name = "capabilities_for_client_supports_method";
@@ -479,8 +480,8 @@ describe('LSP', function()
 
     it('should not send didOpen if the buffer closes before init', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -511,9 +512,9 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+        on_handler = function(err, result, ctx)
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -522,9 +523,9 @@ describe('LSP', function()
 
     it('should check the body sent attaching before init', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -554,12 +555,12 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -568,9 +569,9 @@ describe('LSP', function()
 
     it('should check the body sent attaching after init', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -597,12 +598,12 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -611,9 +612,9 @@ describe('LSP', function()
 
     it('should check the body and didChange full', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -640,8 +641,8 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             exec_lua [[
               vim.api.nvim_buf_set_lines(BUFFER, 1, 2, false, {
                 "boop";
@@ -649,8 +650,8 @@ describe('LSP', function()
             ]]
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -659,9 +660,9 @@ describe('LSP', function()
 
     it('should check the body and didChange full with noeol', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -689,8 +690,8 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             exec_lua [[
               vim.api.nvim_buf_set_lines(BUFFER, 1, 2, false, {
                 "boop";
@@ -698,8 +699,8 @@ describe('LSP', function()
             ]]
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -708,9 +709,9 @@ describe('LSP', function()
 
     it('should check the body and didChange incremental', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -738,8 +739,8 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             exec_lua [[
               vim.api.nvim_buf_set_lines(BUFFER, 1, 2, false, {
                 "123boop";
@@ -747,8 +748,8 @@ describe('LSP', function()
             ]]
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -758,9 +759,9 @@ describe('LSP', function()
     -- TODO(askhan) we don't support full for now, so we can disable these tests.
     pending('should check the body and didChange incremental normal mode editing', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -787,13 +788,13 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             helpers.command("normal! 1Go")
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -802,9 +803,9 @@ describe('LSP', function()
 
     it('should check the body and didChange full with 2 changes', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -831,8 +832,8 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result, ctx)
+          if ctx.method == 'start' then
             exec_lua [[
               vim.api.nvim_buf_set_lines(BUFFER, 1, 2, false, {
                 "321";
@@ -843,8 +844,8 @@ describe('LSP', function()
             ]]
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -853,9 +854,9 @@ describe('LSP', function()
 
     it('should check the body and didChange full lifecycle', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -882,8 +883,8 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          if method == 'start' then
+        on_handler = function(err, result,ctx)
+          if ctx.method == 'start' then
             exec_lua [[
               vim.api.nvim_buf_set_lines(BUFFER, 1, 2, false, {
                 "321";
@@ -895,8 +896,8 @@ describe('LSP', function()
             ]]
             client.notify('finish')
           end
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -907,9 +908,9 @@ describe('LSP', function()
   describe("parsing tests", function()
     it('should handle invalid content-length correctly', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "start", {}, 1};
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -924,22 +925,22 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
+        on_handler = function(err, result, ctx)
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
         end;
       }
     end)
 
     it('should not trim vim.NIL from the end of a list', function()
       local expected_handlers = {
-        {NIL, "shutdown", {}, 1};
-        {NIL, "finish", {}, 1};
-        {NIL, "workspace/executeCommand", {
+        {NIL, {}, {method="shutdown", client_id=1}};
+        {NIL, {}, {method="finish", client_id=1}};
+        {NIL,{
           arguments = { "EXTRACT_METHOD", {metadata = {}}, 3, 0, 6123, NIL },
           command = "refactor.perform",
           title = "EXTRACT_METHOD"
-        }, 1};
-        {NIL, "start", {}, 1};
+        },  {method="workspace/executeCommand", client_id=1}};
+        {NIL, {}, {method="start", client_id=1}};
       }
       local client
       test_rpc_server {
@@ -963,9 +964,9 @@ describe('LSP', function()
           eq(0, code, "exit code", fake_lsp_logfile)
           eq(0, signal, "exit signal", fake_lsp_logfile)
         end;
-        on_handler = function(err, method, params, client_id)
-          eq(table.remove(expected_handlers), {err, method, params, client_id}, "expected handler")
-          if method == 'finish' then
+        on_handler = function(err, result, ctx)
+          eq(table.remove(expected_handlers), {err, result, ctx}, "expected handler")
+          if ctx.method == 'finish' then
             client.stop()
           end
         end;
@@ -1976,7 +1977,7 @@ describe('LSP', function()
   describe('vim.lsp.buf.outgoing_calls', function()
     it('does nothing for an empty response', function()
       local qflist_count = exec_lua([=[
-        require'vim.lsp.handlers'['callHierarchy/outgoingCalls']()
+        require'vim.lsp.handlers'['callHierarchy/outgoingCalls'](nil, nil, {}, nil)
         return #vim.fn.getqflist()
       ]=])
       eq(0, qflist_count)
@@ -2023,7 +2024,7 @@ describe('LSP', function()
           }
         } }
         local handler = require'vim.lsp.handlers'['callHierarchy/outgoingCalls']
-        handler(nil, nil, rust_analyzer_response)
+        handler(nil, rust_analyzer_response, {})
         return vim.fn.getqflist()
       ]=])
 
@@ -2047,7 +2048,7 @@ describe('LSP', function()
   describe('vim.lsp.buf.incoming_calls', function()
     it('does nothing for an empty response', function()
       local qflist_count = exec_lua([=[
-        require'vim.lsp.handlers'['callHierarchy/incomingCalls']()
+        require'vim.lsp.handlers'['callHierarchy/incomingCalls'](nil, nil, {})
         return #vim.fn.getqflist()
       ]=])
       eq(0, qflist_count)
@@ -2095,7 +2096,7 @@ describe('LSP', function()
         } }
 
         local handler = require'vim.lsp.handlers'['callHierarchy/incomingCalls']
-        handler(nil, nil, rust_analyzer_response)
+        handler(nil, rust_analyzer_response, {})
         return vim.fn.getqflist()
       ]=])