Allow to use the current window without resizing it.

lua/codex/init.lua

@@ -17,6 +17,7 @@ local config = {
   autoinstall = true,
   panel     = false,   -- if true, open Codex in a side-panel instead of floating window
   use_buffer = false,  -- if true, capture Codex stdout into a normal buffer instead of a terminal
+  panel_cmd = 'vertical rightbelow vsplit', -- Command to use to create the panel or empty string to use the current window.
 }
 
 function M.setup(user_config)
@@ -88,18 +89,54 @@ local function open_window()
   })
 end
 
---- Open Codex in a side-panel (vertical split) instead of floating window
+--- Open Codex in a panel instead of floating window
 local function open_panel()
-  -- Create a vertical split on the right and show the buffer
-  vim.cmd('vertical rightbelow vsplit')
+  -- Create a window if needed and show the buffer
+  if config.panel_cmd ~= '' then
+    vim.cmd(config.panel_cmd)
+  end
   local win = vim.api.nvim_get_current_win()
   vim.api.nvim_win_set_buf(win, state.buf)
   -- Adjust width according to config (percentage of total columns)
-  local width = math.floor(vim.o.columns * config.width)
-  vim.api.nvim_win_set_width(win, width)
+  if config.width > 0 then
+    local width = math.floor(vim.o.columns * config.width)
+    vim.api.nvim_win_set_width(win, width)
+  end
   state.win = win
 end
 
+local function is_valid_buf(buf)
+  return type(buf) == 'number' and vim.api.nvim_buf_is_valid(buf)
+end
+
+local function win_get_buf(win)
+  if type(win) ~= 'number' or not vim.api.nvim_win_is_valid(win) then
+    return nil
+  end
+
+  local ok, buf = pcall(vim.api.nvim_win_get_buf, win)
+  if ok then
+    return buf
+  end
+end
+
+local function refresh_window_state()
+  if not is_valid_buf(state.buf) then
+    state.win = nil
+    return
+  end
+
+  local current_win = vim.api.nvim_get_current_win()
+  if win_get_buf(current_win) == state.buf then
+    state.win = current_win
+    return
+  end
+
+  if win_get_buf(state.win) ~= state.buf then
+    state.win = nil
+  end
+end
+
 function M.open()
   local function create_clean_buf()
     local buf = vim.api.nvim_create_buf(false, false)
@@ -164,11 +201,7 @@ function M.open()
     end
   end
 
-  local function is_buf_reusable(buf)
-    return type(buf) == 'number' and vim.api.nvim_buf_is_valid(buf)
-  end
-
-  if not is_buf_reusable(state.buf) then
+  if not is_valid_buf(state.buf) then
     state.buf = create_clean_buf()
   end
 
@@ -230,6 +263,8 @@ function M.close()
 end
 
 function M.toggle()
+  refresh_window_state()
+
   if state.win and vim.api.nvim_win_is_valid(state.win) then
     M.close()
   else

tests/specs/codex_spec.lua

@@ -8,6 +8,8 @@ describe('codex.nvim', function()
   before_each(function()
     vim.cmd 'set noswapfile' -- prevent side effects
     vim.cmd 'silent! bwipeout!' -- close any open codex windows
+    package.loaded['codex'] = nil
+    package.loaded['codex.state'] = nil
   end)
 
   it('loads the module', function()
@@ -56,6 +58,44 @@ describe('codex.nvim', function()
     assert(not ok, 'Codex window should be closed')
   end)
 
+  it('opens when the tracked window no longer shows the Codex buffer', function()
+    local codex = require 'codex'
+    local state = require 'codex.state'
+    codex.setup { cmd = { 'echo', 'test' } }
+
+    codex.open()
+    local original_win = vim.api.nvim_get_current_win()
+    local codex_buf = vim.api.nvim_win_get_buf(original_win)
+    local other_buf = vim.api.nvim_create_buf(false, true)
+
+    vim.api.nvim_win_set_buf(original_win, other_buf)
+    codex.toggle()
+
+    local current_win = vim.api.nvim_get_current_win()
+    eq(codex_buf, vim.api.nvim_win_get_buf(current_win))
+    eq(current_win, state.win)
+
+    codex.close()
+  end)
+
+  it('closes when the current window manually shows the Codex buffer', function()
+    local codex = require 'codex'
+    local state = require 'codex.state'
+    codex.setup { cmd = { 'echo', 'test' } }
+
+    codex.open()
+    local codex_win = vim.api.nvim_get_current_win()
+    local codex_buf = vim.api.nvim_win_get_buf(codex_win)
+
+    state.win = nil
+    vim.api.nvim_set_current_win(codex_win)
+    vim.api.nvim_win_set_buf(codex_win, codex_buf)
+    codex.toggle()
+
+    local ok, _ = pcall(vim.api.nvim_win_get_buf, codex_win)
+    assert(not ok, 'Codex window should be closed')
+  end)
+
   it('shows statusline only when job is active but window is not', function()
     require('codex').setup { cmd = { 'sleep', '1000' } }
     require('codex').open()