diff --git a/lua/quicktest.lua b/lua/quicktest.lua
index ede3d8c..ed1f574 100644
--- a/lua/quicktest.lua
+++ b/lua/quicktest.lua
@@ -1,6 +1,7 @@
 -- main module file
 local module = require("quicktest.module")
 
+---@type QuicktestConfig
 local config = {
   adapters = {},
   default_win_mode = "split",
@@ -19,70 +20,84 @@ local config = {
   },
 }
 
----@class MyModule
+---@class Quicktest
 local M = {}
 
 --- @type QuicktestConfig
 M.config = config
 
----@param args QuicktestConfig?
-M.setup = function(args)
-  M.config = vim.tbl_deep_extend("force", M.config, args or {})
+---@param args? QuicktestConfig
+function M.setup(args)
+  args = args or {}
+  M.config = vim.tbl_deep_extend("force", M.config, args)
 end
 
-M.current_win_mode = function()
+function M.current_win_mode()
   return module.current_win_mode(M.config.default_win_mode)
 end
 
 --- @param mode WinModeWithoutAuto
-M.open_win = function(mode)
+function M.open_win(mode)
   return module.try_open_win(mode)
 end
 
 --- @param mode WinModeWithoutAuto
-M.close_win = function(mode)
+function M.close_win(mode)
   return module.try_close_win(mode)
 end
 
 --- @param mode WinModeWithoutAuto
-M.toggle_win = function(mode)
+function M.toggle_win(mode)
   return module.toggle_win(mode)
 end
 
---- @param mode WinMode?
-M.run_previous = function(mode)
-  return module.run_previous(M.config, mode or "auto")
+--- @param mode? WinMode
+function M.run_previous(mode)
+  mode = mode or "auto"
+  return module.run_previous(M.config, mode)
 end
 
---- @param mode WinMode?
---- @param adapter Adapter?
---- @param opts AdapterRunOpts?
-M.run_line = function(mode, adapter, opts)
-  return module.prepare_and_run(M.config, "line", mode or "auto", adapter or "auto", opts or {})
+--- @param mode? WinMode
+--- @param adapter? Adapter
+--- @param opts? AdapterRunOpts
+function M.run_line(mode, adapter, opts)
+  mode = mode or "auto"
+  adapter = adapter or "auto"
+  opts = opts or {}
+  return module.prepare_and_run(M.config, "line", mode, adapter, opts)
 end
 
---- @param mode WinMode?
---- @param adapter Adapter?
---- @param opts AdapterRunOpts?
-M.run_file = function(mode, adapter, opts)
-  return module.prepare_and_run(M.config, "file", mode or "auto", adapter or "auto", opts or {})
+--- @param mode? WinMode
+--- @param adapter? Adapter
+--- @param opts? AdapterRunOpts
+function M.run_file(mode, adapter, opts)
+  mode = mode or "auto"
+  adapter = adapter or "auto"
+  opts = opts or {}
+  return module.prepare_and_run(M.config, "file", mode, adapter, opts)
 end
 
---- @param mode WinMode?
---- @param adapter Adapter?
---- @param opts AdapterRunOpts?
-M.run_dir = function(mode, adapter, opts)
-  return module.prepare_and_run(M.config, "dir", mode or "auto", adapter or "auto", opts or {})
+--- @param mode? WinMode
+--- @param adapter? Adapter
+--- @param opts? AdapterRunOpts
+function M.run_dir(mode, adapter, opts)
+  mode = mode or "auto"
+  adapter = adapter or "auto"
+  opts = opts or {}
+  return module.prepare_and_run(M.config, "dir", mode, adapter, opts)
 end
 
---- @param mode WinMode?
---- @param adapter Adapter?
---- @param opts AdapterRunOpts?
-M.run_all = function(mode, adapter, opts)
-  return module.prepare_and_run(M.config, "all", mode or "auto", adapter or "auto", opts or {})
+--- @param mode? WinMode
+--- @param adapter? Adapter
+--- @param opts? AdapterRunOpts
+function M.run_all(mode, adapter, opts)
+  mode = mode or "auto"
+  adapter = adapter or "auto"
+  opts = opts or {}
+  return module.prepare_and_run(M.config, "all", mode, adapter, opts)
 end
 
-M.cancel_current_run = function()
+function M.cancel_current_run()
   module.kill_current_run()
 end
 
diff --git a/lua/quicktest/colored_printer.lua b/lua/quicktest/colored_printer.lua
index e252e26..0f86a5b 100644
--- a/lua/quicktest/colored_printer.lua
+++ b/lua/quicktest/colored_printer.lua
@@ -1,5 +1,11 @@
 local api = vim.api
 
+---@class ColoredPrinter
+---@field color_groups? table<string, string>
+---@field current_fg? string
+---@field current_bg? string
+---@field current_styles? string[]
+---@field bright_color_bold? boolean
 local ColoredPrinter = {}
 ColoredPrinter.__index = ColoredPrinter
 
@@ -14,6 +20,7 @@ function ColoredPrinter.new()
   return self
 end
 
+---@param index integer
 function ColoredPrinter:get_256_color(index)
   -- Standard 16 colors (0-15)
   if index <= 15 then
@@ -52,13 +59,13 @@ function ColoredPrinter:get_256_color(index)
       return 55 + c * 40
     end
 
-    return string.format("#%02x%02x%02x", color_value(r), color_value(g), color_value(b))
+    return ("#%02x%02x%02x"):format(color_value(r), color_value(g), color_value(b))
   end
 
   -- Grayscale (232-255)
   if index <= 255 then
     local gray = 8 + (index - 232) * 10
-    return string.format("#%02x%02x%02x", gray, gray, gray)
+    return ("#%02x%02x%02x"):format(gray, gray, gray)
   end
 
   return "#ffffff" -- fallback
@@ -86,7 +93,8 @@ function ColoredPrinter:setup_highlight_groups()
 
   for code, color in pairs(basic_colors) do
     local group_name = "QuicktestAnsiColor_" .. code
-    vim.cmd(string.format("highlight %s ctermfg=%s guifg=%s", group_name, color:lower(), color))
+    api.nvim_set_hl(0, group_name, { ctermfg = color:lower(), fg = color })
+    -- vim.cmd(("highlight %s ctermfg=%s guifg=%s"):format(group_name, color:lower(), color))
 
     self.color_groups[code] = group_name
   end
@@ -113,46 +121,56 @@ function ColoredPrinter:setup_highlight_groups()
 
   for code, color in pairs(bg_colors) do
     local group_name = "QuicktestAnsiBgColor_" .. code
-    vim.cmd(string.format("highlight %s ctermbg=%s guibg=%s", group_name, color:lower(), color))
+    api.nvim_set_hl(0, group_name, { ctermbg = color:lower(), bg = color })
+    -- vim.cmd(("highlight %s ctermbg=%s guibg=%s"):format(group_name, color:lower(), color))
 
     self.color_groups[code] = group_name
   end
 
   -- Use Normal highlight group directly to ensure proper default colors
-  vim.cmd("highlight default QuicktestAnsiColorDefault guifg=NONE guibg=NONE")
-  vim.cmd("highlight default link QuicktestAnsiColorDefault Normal")
+  api.nvim_set_hl(0, "QuicktestAnsiColorDefault", { default = true, fg = "NONE", bg = "NONE" })
+  api.nvim_set_hl(0, "QuicktestAnsiColorDefault", { default = true, link = "Normal" })
+  -- vim.cmd("highlight default QuicktestAnsiColorDefault guifg=NONE guibg=NONE")
+  -- vim.cmd("highlight default link QuicktestAnsiColorDefault Normal")
   self.color_groups["default"] = "QuicktestAnsiColorDefault"
 end
 
+---@param fg string
+---@param bg string
+---@param styles string[]
+---@return string
 function ColoredPrinter:get_or_create_color_group(fg, bg, styles)
   -- If no colors or styles are set, use the default group
-  if not fg and not bg and (#styles == 0) then
+  if not (fg or bg) and vim.tbl_isempty(styles) then
     return self.color_groups["default"]
   end
 
+  ---@param str string
   local function sanitize(str)
-    if str then
-      -- Replace # with "hex" and any non-alphanumeric characters with their hex code
-      return str:gsub("#", ""):gsub("[^%w]", function(c)
-        return string.format("%02x", string.byte(c))
-      end)
+    if not str then
+      return ""
     end
-    return ""
+
+    -- Replace # with "hex" and any non-alphanumeric characters with their hex code
+    return str:gsub("#", ""):gsub("[^%w]", function(c) ---@param c string
+      return ("%02x"):format(c:byte())
+    end)
   end
 
+  ---@type table<string, boolean>
   local unique_styles = {}
   for _, style in ipairs(styles) do
     unique_styles[style] = true
   end
-  unique_styles = vim.tbl_keys(unique_styles)
+
   -- sort and uniqize the styles
-  styles = vim.tbl_filter(function(s)
+  styles = vim.tbl_filter(function(s) ---@param s string
     return s ~= ""
-  end, unique_styles)
+  end, vim.tbl_keys(unique_styles))
   table.sort(styles)
 
   local color_key = table.concat(
-    vim.tbl_filter(function(s)
+    vim.tbl_filter(function(s) ---@param s string
       return s ~= ""
     end, { sanitize(fg), sanitize(bg), table.concat(styles, "_") }),
     "_"
@@ -161,7 +179,7 @@ function ColoredPrinter:get_or_create_color_group(fg, bg, styles)
   if not self.color_groups[color_key] then
     local group_name = "QuicktestAnsiColor"
 
-    if #color_key > 0 then
+    if color_key:len() > 0 then
       group_name = group_name .. "_" .. color_key
     end
 
@@ -170,33 +188,33 @@ function ColoredPrinter:get_or_create_color_group(fg, bg, styles)
 
     if fg then
       if fg:match("^#") then
-        cmd = cmd .. string.format(" guifg=%s", fg)
+        cmd = ("%s guifg=%s"):format(cmd, fg)
       elseif self.color_groups[fg] then
         local fg_color = vim.fn.synIDattr(vim.fn.synIDtrans(vim.fn.hlID(self.color_groups[fg])), "fg#")
         if fg_color and fg_color ~= "" then
-          cmd = cmd .. " guifg=" .. fg_color
+          cmd = ("%s guifg=%s"):format(cmd, fg_color)
         end
       end
     end
 
     if bg then
       if bg:match("^#") then
-        cmd = cmd .. string.format(" guibg=%s", bg)
+        cmd = ("%s guibg=%s"):format(cmd, bg)
       elseif self.color_groups[bg] then
         local bg_color = vim.fn.synIDattr(vim.fn.synIDtrans(vim.fn.hlID(self.color_groups[bg])), "bg#")
         if bg_color and bg_color ~= "" then
-          cmd = cmd .. " guibg=" .. bg_color
+          cmd = ("%s guibg=%s"):format(cmd, bg_color)
         end
       end
     end
 
-    if #styles > 0 then
+    if not vim.tbl_isempty(styles) then
       cmd = cmd .. " gui=" .. table.concat(styles, ",")
     end
 
     if start_cmd ~= cmd then
       ---@diagnostic disable-next-line: param-type-mismatch
-      local success, err = pcall(vim.cmd, cmd)
+      local success = pcall(vim.cmd, cmd)
       if not success then
         -- Fallback to basic highlight if command fails
         vim.cmd("highlight " .. group_name)
@@ -208,6 +226,7 @@ function ColoredPrinter:get_or_create_color_group(fg, bg, styles)
   return self.color_groups[color_key]
 end
 
+---@param line string
 function ColoredPrinter:parse_colors(line)
   local result = {}
   local highlights = {}
@@ -222,7 +241,7 @@ function ColoredPrinter:parse_colors(line)
     color_start = #result
   end
 
-  while i <= #line do
+  while i <= line:len() do
     if line:sub(i, i) == "\27" and line:sub(i + 1, i + 1) == "[" then
       local j = line:find("m", i + 2)
       if j then
@@ -321,17 +340,18 @@ function ColoredPrinter:parse_colors(line)
                 local g = tonumber(codes[index + 3])
                 local b = tonumber(codes[index + 4])
                 if r and g and b then
+                  local hex = ("#%02x%02x%02x"):format(r, g, b)
                   if code == 38 then
-                    self.current_fg = string.format("#%02x%02x%02x", r, g, b)
+                    self.current_fg = hex
                   else
-                    self.current_bg = string.format("#%02x%02x%02x", r, g, b)
+                    self.current_bg = hex
                   end
                   index = index + 4
                 end
               end
             elseif codes[index + 1] == "5" then
               if #codes >= index + 2 then
-                local color_index = tonumber(codes[index + 2])
+                local color_index = tonumber(codes[index + 2]) ---@cast color_index integer
                 if color_index and color_index >= 0 and color_index <= 255 then
                   local color_hex = self:get_256_color(color_index)
                   if code == 38 then
@@ -369,19 +389,19 @@ local function get_highlight_def(group)
     return "highlight AnsiColor"
   end
 
-  local hl = vim.api.nvim_get_hl_by_name(group, true)
-  local hl_string = string.format("highlight %s", group)
+  local hl = api.nvim_get_hl(0, { name = group })
+  local hl_string = ("highlight %s"):format(group)
 
-  if hl.foreground then
-    hl_string = hl_string .. string.format(" guifg=#%06x", hl.foreground)
+  if hl.fg then
+    hl_string = ("%s guifg=#%06x"):format(hl_string, hl.fg)
   end
 
-  if hl.background then
-    hl_string = hl_string .. string.format(" guibg=#%06x", hl.background)
+  if hl.bg then
+    hl_string = ("%s guibg=#%06x"):format(hl_string, hl.bg)
   end
 
-  if hl.special then
-    hl_string = hl_string .. string.format(" guisp=#%06x", hl.special)
+  if hl.sp then
+    hl_string = ("%s guisp=#%06x"):format(hl_string, hl.sp)
   end
 
   local gui_attrs = {}
@@ -391,13 +411,14 @@ local function get_highlight_def(group)
     end
   end
 
-  if #gui_attrs > 0 then
-    hl_string = hl_string .. " gui=" .. table.concat(gui_attrs, ",")
+  if not vim.tbl_isempty(gui_attrs) then
+    hl_string = ("%s gui=%s"):format(hl_string, table.concat(gui_attrs, ","))
   end
 
   return hl_string
 end
 
+---@param buf integer
 function ColoredPrinter:set_next_lines(lines, buf, lines_count)
   local parsed_lines = {}
   local parsed_highlights = {}
@@ -414,7 +435,8 @@ function ColoredPrinter:set_next_lines(lines, buf, lines_count)
     for _, h in ipairs(hl) do
       -- print("[" .. h.start .. "," .. h.end_ .. ")", get_highlight_def(h.group))
 
-      api.nvim_buf_add_highlight(buf, -1, h.group, lines_count - 1 + i, h.start, h.end_)
+      vim.hl.range(buf, -1, h.group, { lines_count - 1 + i, h.start }, { lines_count - 1 + i, h.end_ })
+      -- api.nvim_buf_add_highlight(buf, -1, h.group, lines_count - 1 + i, h.start, h.end_)
     end
   end
 
@@ -428,7 +450,7 @@ function ColoredPrinter:debug_print_colors(line)
   print("Original line:", line)
   print("Parsed line:", plain_line)
   for _, hl in ipairs(highlights) do
-    print("[" .. hl.start .. "," .. hl.end_ .. ")", get_highlight_def(hl.group))
+    print(("[%s,%s)"):format(hl.start, hl.end_), get_highlight_def(hl.group))
   end
 end
 
diff --git a/lua/quicktest/fs_utils.lua b/lua/quicktest/fs_utils.lua
index 2fe32ab..66d40d8 100644
--- a/lua/quicktest/fs_utils.lua
+++ b/lua/quicktest/fs_utils.lua
@@ -28,6 +28,7 @@ M.path = (function()
     return path
   end
 
+  ---@return string|false
   local function exists(filename)
     local stat = uv.fs_stat(filename)
     return stat and stat.type or false
diff --git a/lua/quicktest/module.lua b/lua/quicktest/module.lua
index 5415f83..86497a7 100644
--- a/lua/quicktest/module.lua
+++ b/lua/quicktest/module.lua
@@ -1,4 +1,5 @@
 local api = vim.api
+local uv = vim.uv or vim.loop
 local notify = require("quicktest.notify")
 local a = require("plenary.async")
 local u = require("plenary.async.util")
@@ -9,15 +10,20 @@ local p = require("plenary.path")
 local M = {}
 
 ---@alias Adapter string | "auto"
----@alias WinMode 'popup' | 'split' | 'auto'
----@alias WinModeWithoutAuto 'popup' | 'split
+---@alias WinMode "popup" | "split" | "auto"
+---@alias WinModeWithoutAuto "popup" | "split
 
 ---@class AdapterRunOpts
----@field additional_args string[]?
+---@field additional_args? string[]
 
----@alias CmdData {type: 'stdout', raw: string, output: string?, decoded: any} | {type: 'stderr', raw: string, output: string?, decoded: any} | {type: 'exit', code: number}
+---@class CmdData
+---@field type "stdout" | "stderr" | "exit"
+---@field raw string
+---@field output? string
+---@field decoded any
+---@field code? number
 
----@alias RunType 'line' | 'file' | 'dir' | 'all'
+---@alias RunType "line" | "file" | "dir" | "all"
 
 ---@class QuicktestAdapter
 ---@field name string
@@ -26,7 +32,7 @@ local M = {}
 ---@field build_dir_run_params fun(bufnr: integer, cursor_pos: integer[], opts: AdapterRunOpts): any
 ---@field build_all_run_params fun(bufnr: integer, cursor_pos: integer[], opts: AdapterRunOpts): any
 ---@field run fun(params: any, send: fun(data: CmdData)): number
----@field after_run fun(params: any, results: CmdData)?
+---@field after_run nil|fun(params: any, results: CmdData)
 ---@field title fun(params: any): string
 ---@field is_enabled fun(bufnr: number, type: RunType): boolean
 
@@ -35,13 +41,31 @@ local M = {}
 ---@field default_win_mode WinModeWithoutAuto
 ---@field use_builtin_colorizer boolean
 
----@alias JobStatus 'running' | 'finished' | 'canceled'
----@alias CmdJob {id: number, started_at: number, finished_at?: number, pid: number?, status: JobStatus, exit_code?: number}
+---@alias JobStatus "running" | "finished" | "canceled"
+
+---@class CmdJob
+---@field id number
+---@field started_at integer
+---@field finished_at? integer
+---@field pid? number
+---@field status JobStatus
+---@field exit_code? integer
+
+---@class PreviousRun
+---@field type string
+---@field adapter_name string
+---@field bufname string
+---@field cursor_pos integer[]
+
+---@alias PreviousRuns table<string, PreviousRun>
+
 ---@type CmdJob | nil
 local current_job = nil
---- @type {[string]: {type: string, adapter_name: string, bufname: string, cursor_pos: integer[]}} | nil
+
+---@type nil | PreviousRuns
 local previous_run = nil
 
+---@return PreviousRuns
 local function load_previous_run()
   local config_path = p:new(vim.fn.stdpath("data"), "quicktest_previous_runs.json")
 
@@ -59,7 +83,7 @@ end
 
 local function save_previous_run()
   if previous_run then
-    ---@diagnostic disable-next-line: missing-parameter
+    ---@diagnostic disable-next-line:missing-parameter
     a.run(function()
       local config_path = p:new(vim.fn.stdpath("data"), "quicktest_previous_runs.json")
       local current_data = load_previous_run()
@@ -131,23 +155,22 @@ local stderr_ns = vim.api.nvim_create_namespace("quicktest_stderr")
 --- @param opts AdapterRunOpts
 function M.run(adapter, params, config, opts)
   if current_job then
-    if current_job.pid then
-      vim.system({ "kill", tostring(current_job.pid) }):wait()
-      current_job = nil
-    else
+    if not current_job.pid then
       return notify.warn("Already running")
     end
+    vim.system({ "kill", tostring(current_job.pid) }):wait()
+    current_job = nil
   end
 
   --- @param buf integer
   --- @param start integer
-  --- @param finish number
+  --- @param finish integer
   --- @param strict_indexing boolean
   --- @param replacements string[]
   local set_ansi_lines = function(buf, start, finish, strict_indexing, replacements)
     local new_lines = {}
     for i, line in ipairs(replacements) do
-      new_lines[i] = string.gsub(line, "[\27\155][][()#;?%d]*[A-PRZcf-ntqry=><~]", "")
+      new_lines[i] = line:gsub("[\27\155][][()#;?%d]*[A-PRZcf-ntqry=><~]", "")
     end
     vim.api.nvim_buf_set_lines(buf, start, finish, strict_indexing, new_lines)
   end
@@ -155,7 +178,7 @@ function M.run(adapter, params, config, opts)
   local printer = colorized_printer.new()
 
   --- @type CmdJob
-  local job = { id = math.random(10000000000000000), started_at = vim.uv.now(), status = "running" }
+  local job = { id = math.random(10000000000000000), started_at = uv.now(), status = "running" }
   current_job = job
 
   local is_running = function()
@@ -163,12 +186,12 @@ function M.run(adapter, params, config, opts)
   end
 
   local print_buf_status = function(buf, line_count)
-    local passedTime = vim.loop.now() - job.started_at
+    local passedTime = uv.now() - job.started_at
     if job.finished_at then
       passedTime = job.finished_at - job.started_at
     end
 
-    local time_display = string.format("%.2f", passedTime / 1000) .. "s"
+    local time_display = ("%.2f"):format(passedTime / 1000) .. "s"
 
     vim.api.nvim_buf_clear_namespace(buf, status_ns, 0, -1)
 
@@ -179,15 +202,17 @@ function M.run(adapter, params, config, opts)
       hl_group = "DiagnosticInfo"
     else
       if job.status == "canceled" then
-        line = "Canceled " .. time_display
+        line = "Canceled "
         hl_group = "DiagnosticWarn"
       elseif job.exit_code ~= 0 then
-        line = "Failed " .. time_display
+        line = "Failed "
         hl_group = "DiagnosticError"
       else
-        line = "Passed " .. time_display
+        line = "Passed "
         hl_group = "DiagnosticOk"
       end
+
+      line = line .. time_display
     end
 
     vim.api.nvim_buf_set_lines(buf, line_count - 1, line_count, false, {
@@ -264,13 +289,7 @@ function M.run(adapter, params, config, opts)
             end
 
             for i, _ in ipairs(errored_lines) do
-              vim.highlight.range(
-                buf,
-                stderr_ns,
-                "DiagnosticError",
-                { i + lines_count - 2, 0 },
-                { i + lines_count - 2, -1 }
-              )
+              vim.hl.range(buf, stderr_ns, "DiagnosticError", { i + lines_count - 2, 0 }, { i + lines_count - 2, -1 })
             end
 
             print_buf_status(buf, lines_count + new_lines_count)
@@ -322,7 +341,7 @@ function M.run(adapter, params, config, opts)
 
       if result.type == "exit" then
         job.exit_code = result.code
-        job.finished_at = vim.uv.now()
+        job.finished_at = uv.now()
         job.status = "finished"
 
         if adapter.after_run then
@@ -386,7 +405,7 @@ local function get_adapter_and_params(config, type, adapter_name, current_buffer
 end
 
 --- @param config QuicktestConfig
---- @param type 'line' | 'file' | 'dir' | 'all'
+--- @param type "line" | "file" | "dir" | "all"
 --- @param mode WinMode
 --- @param adapter_name Adapter
 --- @param opts AdapterRunOpts
@@ -486,7 +505,7 @@ function M.kill_current_run()
     vim.system({ "kill", tostring(current_job.pid) }):wait()
 
     job.status = "canceled"
-    job.finished_at = vim.uv.now()
+    job.finished_at = uv.now()
   end
 end
 
diff --git a/lua/quicktest/notify.lua b/lua/quicktest/notify.lua
index 323269c..1c1a3c6 100644
--- a/lua/quicktest/notify.lua
+++ b/lua/quicktest/notify.lua
@@ -1,10 +1,10 @@
 local M = {}
 
 ---@param msg string
----@param level number
+---@param level vim.log.levels
 local function notify(msg, level)
   vim.schedule(function()
-    vim.api.nvim_notify(msg, level, { title = "Quicktest" })
+    vim.notify(msg, level, { title = "Quicktest" })
   end)
 end