feat: add logger and redirect existing prints/notifies through it (#383)

Fixes #356

Author: AntoineGS

README.md

@@ -87,6 +87,15 @@ require('copilot').setup({
     cvs = false,
     ["."] = false,
   },
+  logger = {
+    log_to_file = false,
+    file = vim.fn.stdpath("log") .. "/copilot-lua.log",
+    file_log_level = vim.log.levels.WARN,
+    print_log = true,
+    print_log_level = vim.log.levels.WARN,
+    trace_lsp = "off", -- "off" | "messages" | "verbose"
+    trace_lsp_progress = false,
+  },
   copilot_node_command = 'node', -- Node.js version must be > 18.x
   workspace_folders = {},
   copilot_model = "",  -- Current LSP default is gpt-35-turbo, supports gpt-4o-copilot
@@ -183,6 +192,32 @@ require("copilot").setup {
 }
 ```
 
+### logger
+
+When `log_to_file` is true, logs will be written to the `file` for anything of `file_log_level` or higher.
+When `print_log` is true, logs will be printed to NeoVim (using `notify`) for anything of `print_log_level` or higher.
+File logging is done asynchronously to minimize performance impacts, however there is still some overhead.
+
+Log levels used are the ones defined in `vim.log`:
+
+```lua
+vim.log = {
+  levels = {
+    TRACE = 0,
+    DEBUG = 1,
+    INFO = 2,
+    WARN = 3,
+    ERROR = 4,
+    OFF = 5,
+  },
+}
+```
+
+`trace_lsp` can either be `off`, `messages` which will output the LSP messages, or `verbose` which adds additonal information to the message.
+When `trace_lsp_progress` is true, LSP progress messages will also be logged.
+
+Careful turning on all logging features as the log files may get very large over time, and are not pruned by the application.
+
 ### copilot_node_command
 
 Use this field to provide the path to a specific node version such as one installed by nvm. Node.js version must be 18.x or newer.

lua/copilot/auth.lua

@@ -1,5 +1,6 @@
 local api = require("copilot.api")
 local c = require("copilot.client")
+local logger = require("copilot.logger")
 
 local M = {}
 
@@ -145,7 +146,7 @@ local function find_config_path()
     if vim.fn.isdirectory(config) > 0 then
       return config
     else
-      print("Error: could not find config path")
+      logger.error("could not find config path")
     end
   end
 end

lua/copilot/client.lua

@@ -1,6 +1,7 @@
 local api = require("copilot.api")
 local config = require("copilot.config")
 local util = require("copilot.util")
+local logger = require("copilot.logger")
 
 local is_disabled = false
 
@@ -9,6 +10,7 @@ local M = {
   id = nil,
   --- @class copilot_capabilities:lsp.ClientCapabilities
   --- @field copilot table<'openURL', boolean>
+  --- @field workspace table<'workspaceFolders', boolean>
   capabilities = nil,
   config = nil,
   node_version = nil,
@@ -21,7 +23,8 @@ local M = {
 local function store_client_id(id)
   if M.id and M.id ~= id then
     if vim.lsp.get_client_by_id(M.id) then
-      error("unexpectedly started multiple copilot servers")
+      logger.error("unexpectedly started multiple copilot servers")
+      return
     end
   end
 
@@ -92,7 +95,7 @@ end
 ---@param force? boolean
 function M.buf_attach(force)
   if is_disabled then
-    print("[Copilot] Offline")
+    logger.warn("copilot is disabled")
     return
   end
 
@@ -101,7 +104,7 @@ function M.buf_attach(force)
   end
 
   if not M.config then
-    vim.notify("[Copilot] Cannot attach: configuration not initialized", vim.log.levels.ERROR)
+    logger.error("cannot attach: configuration not initialized")
     return
   end
 
@@ -110,14 +113,14 @@ function M.buf_attach(force)
 
   local ok, client_id_or_err = pcall(lsp_start, M.config)
   if not ok then
-    vim.notify(string.format("[Copilot] Failed to start LSP client: %s", client_id_or_err), vim.log.levels.ERROR)
+    logger.error(string.format("failed to start LSP client: %s", client_id_or_err))
     return
   end
 
   if client_id_or_err then
     store_client_id(client_id_or_err)
   else
-    vim.notify("[Copilot] LSP client failed to start (no client ID returned)", vim.log.levels.ERROR)
+    logger.error("LSP client failed to start (no client ID returned)")
   end
 end
 
@@ -138,21 +141,22 @@ end
 ---@param callback fun(client:table):nil
 function M.use_client(callback)
   if is_disabled then
-    print("[Copilot] Offline")
+    logger.warn("copilot is offline")
     return
   end
 
   local client = M.get() --[[@as table]]
 
   if not client then
     if not M.config then
-      error("copilot.setup is not called yet")
+      logger.error("copilot.setup is not called yet")
+      return
     end
 
     local client_id, err = vim.lsp.start_client(M.config)
 
     if not client_id then
-      error(string.format("[Copilot] Error starting LSP Client: %s", err))
+      logger.error(string.format("error starting LSP client: %s", err))
       return
     end
 
@@ -169,7 +173,7 @@ function M.use_client(callback)
   local timer, err, _ = vim.loop.new_timer()
 
   if not timer then
-    error(string.format("[Copilot] Error creating timer: %s", err))
+    logger.error(string.format("error creating timer: %s", err))
     return
   end
 
@@ -191,15 +195,15 @@ local function prepare_client_config(overrides)
 
   if vim.fn.executable(node) ~= 1 then
     local err = string.format("copilot_node_command(%s) is not executable", node)
-    vim.notify("[Copilot] " .. err, vim.log.levels.ERROR)
+    logger.error(err)
     M.startup_error = err
     return
   end
 
   local agent_path = vim.api.nvim_get_runtime_file("copilot/dist/language-server.js", false)[1]
   if not agent_path or vim.fn.filereadable(agent_path) == 0 then
     local err = string.format("Could not find language-server.js (bad install?) : %s", tostring(agent_path))
-    vim.notify("[Copilot] " .. err, vim.log.levels.ERROR)
+    logger.error(err)
     M.startup_error = err
     return
   end
@@ -272,11 +276,14 @@ local function prepare_client_config(overrides)
         set_editor_info_params.authProvider = provider_url and {
           url = provider_url,
         } or nil
+
+        logger.debug("data for setEditorInfo LSP call", set_editor_info_params)
         api.set_editor_info(client, set_editor_info_params, function(err)
           if err then
-            vim.notify(string.format("[copilot] setEditorInfo failure: %s", err), vim.log.levels.ERROR)
+            logger.error(string.format("setEditorInfo failure: %s", err))
           end
         end)
+        logger.trace("setEditorInfo has been called")
         M.initialized = true
       end)
     end,
@@ -299,6 +306,7 @@ local function prepare_client_config(overrides)
       copilotIntegrationId = "vscode-chat",
     },
     workspace_folders = workspace_folders,
+    trace = config.get("trace") or "off",
   }, overrides)
 end
 
@@ -339,12 +347,12 @@ end
 
 function M.add_workspace_folder(folder_path)
   if type(folder_path) ~= "string" then
-    vim.notify("[Copilot] Workspace folder path must be a string", vim.log.levels.ERROR)
+    logger.error("workspace folder path must be a string")
     return false
   end
 
   if vim.fn.isdirectory(folder_path) ~= 1 then
-    vim.notify("[Copilot] Invalid workspace folder: " .. folder_path, vim.log.levels.ERROR)
+    logger.error("invalid workspace folder: " .. folder_path)
     return false
   end
 
@@ -379,9 +387,9 @@ function M.add_workspace_folder(folder_path)
         removed = {},
       },
     })
-    vim.notify("[Copilot] Added workspace folder: " .. folder_path, vim.log.levels.INFO)
+    logger.notify("added workspace folder: " .. folder_path)
   else
-    vim.notify("[Copilot] Workspace folder added for next session: " .. folder_path, vim.log.levels.INFO)
+    logger.notify("workspace folder will be added on next session: " .. folder_path)
   end
 
   return true

lua/copilot/config.lua

@@ -1,3 +1,5 @@
+local logger = require("copilot.logger")
+
 ---@class copilot_config
 local default_config = {
   ---@class copilot_config_panel
@@ -33,6 +35,17 @@ local default_config = {
       dismiss = "<C-]>",
     },
   },
+  ---@class copilot_config_logging
+  logger = {
+    log_to_file = false,
+    file = vim.fn.stdpath("log") .. "/copilot-lua.log",
+    file_log_level = vim.log.levels.WARN,
+    print_log = true,
+    print_log_level = vim.log.levels.WARN,
+    ---@type string<'off'|'messages'|'verbose'>
+    trace_lsp = "off",
+    trace_lsp_progress = false,
+  },
   ---@deprecated
   ft_disable = nil,
   ---@type table<string, boolean>
@@ -52,12 +65,13 @@ local default_config = {
 }
 
 local mod = {
+  ---@type copilot_config
   config = nil,
 }
 
 function mod.setup(opts)
   if mod.config then
-    vim.notify("[Copilot] config is already set", vim.log.levels.WARN)
+    logger.warn("config is already set")
     return mod.config
   end
 
@@ -80,7 +94,8 @@ end
 ---@param key? string
 function mod.get(key)
   if not mod.config then
-    error("[Copilot] not initialized")
+    logger.error("not initialized")
+    return
   end
 
   if key then
@@ -94,7 +109,8 @@ end
 ---@param value any
 function mod.set(key, value)
   if not mod.config then
-    error("[Copilot] not initialized")
+    logger.error("not initialized")
+    return
   end
 
   mod.config[key] = value

lua/copilot/init.lua

@@ -1,6 +1,8 @@
 local M = { setup_done = false }
 local config = require("copilot.config")
 local highlight = require("copilot.highlight")
+local logger = require("copilot.logger")
+local client = require("copilot.client")
 
 local create_cmds = function()
   vim.api.nvim_create_user_command("CopilotDetach", function()
@@ -39,6 +41,11 @@ M.setup = function(opts)
   end
 
   require("copilot.command").enable()
+  logger.setup(conf.logger)
+
+  logger.debug("active plugin config:", config)
+  -- logged here to ensure the logger is setup
+  logger.debug("active LSP config (may change runtime):", client.config)
 
   M.setup_done = true
 end