feat: add LvimUpdate command (#1634)

* feat: add prelimenary LvimUpdate command

* feat: use native process management

* feat: add a telescope change-log utility

* fix: update readme to include the new command

lua/bootstrap.lua

@@ -1,5 +1,7 @@
 local M = {}
--- It's not safe to require 'utils' without adjusting the runtimepath
+
+---Join path segments that were passed as input
+---@return string
 function _G.join_paths(...)
   local uv = vim.loop
   local path_sep = uv.os_uname().version:match "Windows" and "\\" or "/"
@@ -7,6 +9,8 @@ function _G.join_paths(...)
   return result
 end
 
+---Get the full path to `$LUNARVIM_RUNTIME_DIR`
+---@return string
 function _G.get_runtime_dir()
   local lvim_runtime_dir = os.getenv "LUNARVIM_RUNTIME_DIR"
   if not lvim_runtime_dir then
@@ -16,6 +20,8 @@ function _G.get_runtime_dir()
   return lvim_runtime_dir
 end
 
+---Get the full path to `$LUNARVIM_CONFIG_DIR`
+---@return string
 function _G.get_config_dir()
   local lvim_config_dir = os.getenv "LUNARVIM_CONFIG_DIR"
   if not lvim_config_dir then
@@ -24,6 +30,8 @@ function _G.get_config_dir()
   return lvim_config_dir
 end
 
+---Get the full path to `$LUNARVIM_CACHE_DIR`
+---@return string
 function _G.get_cache_dir()
   local lvim_cache_dir = os.getenv "LUNARVIM_CACHE_DIR"
   if not lvim_cache_dir then
@@ -32,7 +40,11 @@ function _G.get_cache_dir()
   return lvim_cache_dir
 end
 
+---Get currently installed version of LunarVim
+---@param type string can be "short"
+---@return string
 function _G.get_version(type)
+  type = type or ""
   local lvim_full_ver = vim.fn.system("git -C " .. get_runtime_dir() .. "/lvim describe --tags")
 
   if string.match(lvim_full_ver, "%d") == nil then
@@ -45,10 +57,13 @@ function _G.get_version(type)
   end
 end
 
+---Initialize the `&runtimepath` variables and prepare for startup
+---@return table
 function M:init()
   self.runtime_dir = get_runtime_dir()
   self.config_dir = get_config_dir()
   self.cache_path = get_cache_dir()
+  self.repo_dir = join_paths(self.runtime_dir, "lvim")
 
   self.pack_dir = join_paths(self.runtime_dir, "site", "pack")
   self.packer_install_dir = join_paths(self.runtime_dir, "site", "pack", "packer", "start", "packer.nvim")
@@ -92,4 +107,83 @@ function M:init()
   return self
 end
 
+---Update LunarVim
+---pulls the latest changes from github and, resets the startup cache
+function M:update()
+  M:update_repo()
+  M:reset_cache()
+  vim.schedule(function()
+    -- TODO: add a changelog
+    vim.notify("Update complete", vim.log.levels.INFO)
+  end)
+end
+
+local function git_cmd(subcmd)
+  local Job = require "plenary.job"
+  local Log = require "core.log"
+  local repo_dir = join_paths(get_runtime_dir(), "lvim")
+  local args = { "-C", repo_dir }
+  vim.list_extend(args, subcmd)
+
+  local stderr = {}
+  local stdout, ret = Job
+    :new({
+      command = "git",
+      args = args,
+      cwd = repo_dir,
+      on_stderr = function(_, data)
+        table.insert(stderr, data)
+      end,
+    })
+    :sync()
+
+  if not vim.tbl_isempty(stderr) then
+    Log:debug(stderr)
+  end
+
+  if not vim.tbl_isempty(stdout) then
+    Log:debug(stdout)
+  end
+
+  return ret
+end
+
+---pulls the latest changes from github
+function M:update_repo()
+  local Log = require "core.log"
+  local sub_commands = {
+    fetch = { "fetch" },
+    diff = { "diff", "--quiet", "@{upstream}" },
+    merge = { "merge", "--ff-only", "--progress" },
+  }
+  Log:info "Checking for updates"
+
+  local ret = git_cmd(sub_commands.fetch)
+  if ret ~= 0 then
+    error "Update failed! Check the log for further information"
+  end
+
+  ret = git_cmd(sub_commands.diff)
+
+  if ret == 0 then
+    Log:info "LunarVim is already up-to-date"
+    return
+  end
+
+  ret = git_cmd(sub_commands.merge)
+
+  if ret ~= 0 then
+    error "Error: unable to guarantee data integrity while updating your branch"
+    error "Please pull the changes manually instead."
+  end
+end
+
+---Reset any startup cache files used by Packer and Impatient
+---Tip: Useful for clearing any outdated settings
+function M:reset_cache()
+  _G.__luacache.clear_cache()
+  _G.__luacache.save_cache()
+  require("plugin-loader"):cache_reset()
+end
+
 return M