mlua-debugger.nvim

Standalone debugger for mLua/MSW in Neovim using MSW's binary protocol.

Features

• Direct communication with MSW debugger (binary protocol, not DAP JSON-RPC)
• Built-in UI with:
  • Stack trace panel
  • Variables panel
  • Console output panel
  • Stopped line highlighting with virtual text
• No external dependencies (no nvim-dap required)

Requirements

• Neovim 0.9+

Installation

lazy.nvim

{
  "seokgukim/mlua-debugger.nvim",
  config = function()
    require("mlua-debugger").setup()
  end,
}

Configuration

require("mlua-debugger").setup({
  port = 51300,       -- Default port to connect to
  host = "localhost", -- Host to connect to
  timeout = 300000,    -- Connection timeout in ms
  auto_ui = true,     -- Automatically open/close UI on attach/disconnect
  ui = {
    width = 40,       -- Width of side panels
    height = 10,      -- Height of console panel
    position = "right", -- Position of side panels: "left" or "right"
  },
  keymaps = {         -- Set to false to disable all keymaps
    continue = "<F5>",
    toggle_breakpoint = "<F9>",
    step_over = "<F10>",
    step_into = "<F11>",
    step_out = "<S-F11>",
    continue_leader = "<leader>dc",
    toggle_breakpoint_leader = "<leader>db",
    clear_breakpoints = "<leader>dB",
    step_over_leader = "<leader>ds",
    step_into_leader = "<leader>di",
    step_out_leader = "<leader>do",
    stack_trace = "<leader>dt",
    attach = "<leader>da",
    disconnect = "<leader>dd",
    toggle_ui = "<leader>du",
  },
  deprecated_commands = true, -- Set to false to hide deprecated command aliases from completion
})

Disabling Keymaps

To disable all default keymaps and define your own:

require("mlua-debugger").setup({
  keymaps = false,  -- Disable all default keymaps
})

To disable specific keymaps:

require("mlua-debugger").setup({
  keymaps = {
    continue = false,  -- Disable <F5>
    step_over = false, -- Disable <F10>
    -- Other keymaps remain default
  },
})

Commands

The plugin provides a unified :MluaDebug <subcommand> pattern:

New Command Style

Command	Description
:MluaDebug attach [port]	Attach to MSW debugger
:MluaDebug disconnect	Disconnect from debugger
:MluaDebug continue	Continue execution
:MluaDebug stepover	Step over
:MluaDebug stepinto	Step into
:MluaDebug stepout	Step out
:MluaDebug breakpoint	Toggle breakpoint at cursor
:MluaDebug clearbreakpoints	Clear all breakpoints
:MluaDebug stack	Show stack trace
:MluaDebug eval <expr>	Evaluate expression
:MluaDebug uiopen	Open debug UI panels
:MluaDebug uiclose	Close debug UI panels
:MluaDebug uitoggle	Toggle debug UI panels
:MluaDebug uiclear	Clear console output

Legacy Commands (Deprecated)

The old command style is still supported but deprecated. A warning will be shown when using them:

Old Command	New Command
:MluaDebugAttach [port]	:MluaDebug attach [port]
:MluaDebugDisconnect	:MluaDebug disconnect
:MluaDebugContinue	:MluaDebug continue
:MluaDebugStepOver	:MluaDebug stepover
:MluaDebugStepInto	:MluaDebug stepinto
:MluaDebugStepOut	:MluaDebug stepout
:MluaDebugToggleBreakpoint	:MluaDebug breakpoint
:MluaDebugClearBreakpoints	:MluaDebug clearbreakpoints
:MluaDebugStackTrace	:MluaDebug stack
:MluaDebugEval <expr>	:MluaDebug eval <expr>
:MluaDebugUIOpen	:MluaDebug uiopen
:MluaDebugUIClose	:MluaDebug uiclose
:MluaDebugUIToggle	:MluaDebug uitoggle
:MluaDebugUIClear	:MluaDebug uiclear

Keymaps (mlua filetype)

Key	Description
<F5>	Continue
<F9>	Toggle breakpoint
<F10>	Step over
<F11>	Step into
<S-F11>	Step out
<leader>dc	Continue
<leader>db	Toggle breakpoint
<leader>dB	Clear breakpoints
<leader>ds	Step over
<leader>di	Step into
<leader>do	Step out
<leader>dt	Stack trace
<leader>da	Attach
<leader>dd	Disconnect
<leader>du	Toggle UI

Highlight Groups

Highlight	Description
MluaDebuggerStoppedLine	Background color for stopped line
MluaDebuggerStackFrame	Stack frame text
MluaDebuggerStackCurrent	Current stack frame
MluaDebuggerVariableName	Variable names
MluaDebuggerVariableType	Variable types
MluaDebuggerVariableValue	Variable values
MluaDebuggerConsoleInfo	Console info messages
MluaDebuggerConsoleError	Console error messages
MluaDebuggerPanelTitle	Panel titles

License

MIT