feat: add ability to set custom copilot binary

Fixes #407

Author: AntoineGS

README.md

@@ -129,6 +129,7 @@ require('copilot').setup({
 
     return true
   end,
+  lsp_binary = nil,
   server_opts_overrides = {},
 })
 ```
@@ -343,6 +344,18 @@ require("copilot").setup {
 }
 ```
 
+### lsp_binary
+
+This allows you to specify the path to the copilot lsp binary.
+This will disable the download of the binary and use the one specified.
+example:
+
+```lua
+require("copilot").setup {
+  lsp_binary = "/home/user/.local/bin/copilot-language-server",
+}
+```
+
 ## Commands
 
 `copilot.lua` defines the `:Copilot` command that can perform various actions. It has completion support, so try it out.

lua/copilot/config.lua

@@ -75,6 +75,8 @@ local default_config = {
 
     return true
   end,
+  ---@type string|nil
+  lsp_binary = nil,
 }
 
 local mod = {

lua/copilot/init.lua

@@ -4,6 +4,7 @@ local highlight = require("copilot.highlight")
 local logger = require("copilot.logger")
 local client = require("copilot.client")
 local auth = require("copilot.auth")
+local lsp_binary = require("copilot.lsp_binary")
 
 local create_cmds = function()
   vim.api.nvim_create_user_command("CopilotDetach", function()
@@ -41,6 +42,7 @@ M.setup = function(opts)
     create_cmds()
   end
 
+  lsp_binary.setup(conf.lsp_binary)
   require("copilot.command").enable()
   logger.setup(conf.logger)
 

lua/copilot/lsp_binary.lua

@@ -265,4 +265,27 @@ function M.get_copilot_server_info()
   return M.copilot_server_info
 end
 
+function M.setup(filepath)
+  if not filepath then
+    return M
+  end
+
+  if not vim.fn.filereadable(filepath) then
+    logger.error("copilot-language-server not found at " .. filepath)
+    return M
+  end
+
+  M.copilot_server_info = {
+    path = "",
+    filename = "",
+    absolute_path = "",
+    absolute_filepath = vim.fs.normalize(filepath),
+    extracted_filename = "",
+  }
+
+  logger.debug("using custom copilot-language-server binary:", M.copilot_server_info.absolute_filepath)
+
+  M.initialized = true
+end
+
 return M