fix(mcp): fix some issues found in CR

Author: cairijun

lua/codecompanion/interactions/chat/init.lua

@@ -523,7 +523,7 @@ function Chat.new(args)
 
   self:update_metadata()
 
-  require("codecompanion.mcp").start_all_if_not_started()
+  require("codecompanion.mcp").start_all()
 
   -- Likely this hasn't been set by the time the user opens the chat buffer
   if not _G.codecompanion_current_context then

lua/codecompanion/mcp/client.lua

@@ -204,9 +204,11 @@ Client.__index = Client
 
 Client.static = {}
 Client.static.methods = {
-  new_transport = { default = function(name, cfg, methods)
-    return StdioTransport:new(name, cfg, methods)
-  end },
+  new_transport = {
+    default = function(name, cfg, methods)
+      return StdioTransport:new(name, cfg, methods)
+    end,
+  },
   json_decode = { default = vim.json.decode },
   json_encode = { default = vim.json.encode },
   schedule_wrap = { default = vim.schedule_wrap },
@@ -234,7 +236,6 @@ function Client:new(name, cfg, methods)
   }, self)
 end
 
-
 ---Start the client.
 function Client:start()
   if self.transport:started() then
@@ -272,7 +273,6 @@ function Client:_start_initialization()
   }, function(resp)
     if resp.error then
       log:error("[MCP.%s] initialization failed: %s", self.name, resp)
-
       return
     end
     log:info("[MCP.%s] initialized successfully.", self.name)
@@ -302,6 +302,14 @@ function Client:_on_transport_close(err)
   else
     log:warn("[MCP.%s] exited with error: %s", self.name, err)
   end
+  for id, handler in pairs(self.resp_handlers) do
+    -- Notify all pending requests of the transport closure
+    pcall(handler, {
+      jsonrpc = "2.0",
+      id = id,
+      error = { code = JsonRpc.ERROR_INTERNAL, message = "MCP server connection closed" },
+    })
+  end
   utils.fire("MCPServerExit", { name = self.name, err = err })
 end
 
@@ -510,7 +518,7 @@ end
 
 ---Call a tool on the MCP server
 ---@param name string The name of the tool to call
----@param args table<string, any> The arguments to pass to the tool
+---@param args? table<string, any> The arguments to pass to the tool
 ---@param callback fun(ok: boolean, result_or_error: MCP.CallToolResult | string) Callback function that receives (ok, result_or_error)
 ---@param opts? table { timeout_ms? integer }
 ---@return integer req_id
@@ -555,8 +563,8 @@ function Client:refresh_tools()
 
       -- pagination handling
       local next_cursor = resp.result and resp.result.nextCursor
-      if next_cursor and #tools >= MAX_TOOLS_PER_SERVER then
-        log:warn("[MCP.%s] returned too many tools (%d), stop further loading", self.name, #tools)
+      if next_cursor and #all_tools >= MAX_TOOLS_PER_SERVER then
+        log:warn("[MCP.%s] returned too many tools (%d), stop further loading", self.name, #all_tools)
       elseif next_cursor then
         log:info("[MCP.%s] loading more tools with cursor: %s", self.name, next_cursor)
         return load_tools(next_cursor)

lua/codecompanion/mcp/init.lua

@@ -25,7 +25,7 @@ local M = {}
 local clients = {}
 
 ---Start all configured MCP servers if not already started
-function M.start_all_if_not_started()
+function M.start_all()
   local mcp_cfg = require("codecompanion.config").interactions.chat.mcp
   for name, cfg in pairs(mcp_cfg.servers or {}) do
     if not clients[name] then

lua/codecompanion/types.lua

@@ -55,7 +55,7 @@
 ---@alias MCP.ContentBlock MCP.TextContent|any
 
 ---@class MCP.CallToolResult
----@field isError boolean
+---@field isError? boolean
 ---@field content MCP.ContentBlock[]
 
 ---@meta Tree-sitter

tests/stubs/mcp/tools.jsonl

@@ -1,5 +1,5 @@
 {"name":"echo","description":"Echoes back the input","inputSchema":{"type":"object","properties":{"value":{"type":"string","description":"A string value to echo back"}},"required":["value"]}}
-{"name":"say_hi","description":"Say Hi to you","inputSchema":{"type":"object","properties":{"name":{"type":"string","description":"Who are you?"}},"required":[""]}}
+{"name":"say_hi","description":"Say Hi to you","inputSchema":{"type":"object","properties":{"name":{"type":"string","description":"Who are you?"}},"required":[]}}
 {"name":"make_list","description":"Creates a list of items","inputSchema":{"type":"object","properties":{"count":{"type":"number","description":"Number of items"},"item":{"oneOf":[{"type":"string"},{"type":"number"}],"description":"The item to repeat in the list"}},"required":["count","item"]}}
 {"name":"math_add","title":"Math/Add","description":"Adds two numbers","inputSchema":{"type":"object","properties":{"a":{"type":"number","description":"The first number to add"},"b":{"type":"number","description":"The second number to add"}},"required":["a","b"]}}
 {"name":"math_mul","title":"Math/Mul","description":"Multiply two numbers","inputSchema":{"type":"object","properties":{"a":{"type":"number","description":"The first number to multiply"},"b":{"type":"number","description":"The second number to multiply"}},"required":["a","b"]}}