# turbo-debug.nvim

A zero-config debugging experience for Neovim 0.12+. One plugin install, full
IDE-class debugging: inline variable values, hover inspection, persistent
breakpoints, watch expressions, and modal keybindings that just work.

Inspired by Turbo Pascal — the first IDE where you could just hit a key
and start debugging.

![turbo-debug screenshot](assets/screenshot.png)

## Install

```lua
vim.pack.add("swaits/turbo-debug")
```

That's it. No other config needed. See `:help turbo-debug` for customization.

## How It Works

turbo-debug is **modal**. Press `<leader>dd` and you enter debug mode — the
dap-ui layout opens, keybindings activate, virtual text lights up, and
you're debugging. Press `<leader>dd` again (or `q`) and everything
disappears: the session terminates, the UI closes, and every keybinding is
restored to exactly what it was.

This modal approach is inspired by
[debugmaster.nvim](https://github.com/MironPascalCaseFan/debugmaster.nvim).
During a debug session you **navigate** code and **inspect** state; you
don't **edit**. So debug mode shadows editing keys (`c`, `d`, `s`, `r`,
`x`) with debug actions and leaves all navigation keys untouched (`h`,
`j`, `k`, `l`, `w`, `b`, `e`, `f`, `/`, `n`, etc.).

### A nice text *and* GUI debugger

The modal keymap is deliberately **left-hand optimized** so the right hand
stays on the mouse for interacting with the dap-ui panes:

- **Left hand on keyboard**: `c s d r C x X D W E q R` fire the twelve
  rapid-use debug actions without leaving home row.
- **Right hand on mouse**: click into Watches/Scopes/Stacks/Breakpoints
  panes to expand trees, jump to frames, add watch expressions, or toggle
  breakpoints from the GUI.

Only two modal keys live on the right hand, both by universal convention:
`K` for hover (matches the LSP hover key) and `?` for help.

Inside dap-ui panes, the native dap-ui mappings still work — `d` removes a
watch, `r` sends to REPL, `e` edits. The modal `d` (step-into) and `r`
(step-out) yield to dap-ui in those buffers so you can manage the GUI
without exiting debug mode.

## Keybindings

Everything lives under `<leader>d` (with
[which-key](https://github.com/folke/which-key.nvim) support if installed):

| Key | Action |
|-----|--------|
| `<leader>dd` | Toggle debug mode |
| `<leader>dx` | Toggle breakpoint |
| `<leader>dX` | Conditional breakpoint |
| `<leader>dD` | Clear all breakpoints |

During debug mode, single-key controls:

| Key | Action | Key | Action |
|-----|--------|-----|--------|
| `c` | Continue | `x` | Toggle breakpoint |
| `s` | Step over | `X` | Conditional breakpoint |
| `d` | Step into | `D` | Clear all breakpoints |
| `r` | Step out | `W` | Watch expression |
| `C` | Run to cursor | `K` | Hover / inspect |
| `q` | Smart quit (terminate → exit) | `E` | Eval in REPL |
| `R` | Restart session | `?` | Help popup |

`q` is context-aware: if a session is running, it terminates the session
and leaves you in debug mode (so you can read the console and inspect
the exit state). If no session is running, `q` exits debug mode entirely.

Press `?` during debug mode for a quick reference that also lists dap-ui's
native in-pane bindings (`<CR>`, `e`, `o`, `d`, `r`, `t`).

### Extending keymaps

Every key is user-overridable. Remap, disable, or add bindings via
`setup()`:

```lua
require("turbo-debug").setup({
  keys = {
    step_over = "n",       -- remap a modal key
    watch = false,         -- disable a modal key
  },
  global_keys = {
    toggle = "<leader>D",  -- change the toggle chord
  },
  sidebar = "right",       -- "left" (default) or "right"
  help_on_enter = true,    -- show help popup on debug mode entry (default false)

  -- Optional theme swap for debug sessions. `nil` (default) keeps the
  -- current colorscheme; any string is passed to `:colorscheme` on enter
  -- and the original is restored on exit.
  colorscheme = nil,

  -- Auto stop-on-entry when no breakpoints are set (Turbo Pascal model):
  -- press `c` on an empty-BP project and the debugger pauses at main().
  -- Set false to always run until a breakpoint instead.
  stop_on_entry_when_no_breakpoints = true,

  -- Cap per-line value length in Scopes/Watches. Values longer than this
  -- get truncated with `…`. Default 2000 only catches pathological register
  -- dumps. Set 0 to disable truncation entirely.
  max_value_width = 2000,

  -- Console repaint throttle (ms). Max 1000/console_refresh_ms redraws per
  -- second when the debugged program spams stdout. Prevents editor DOS.
  console_refresh_ms = 50,

  -- Clear the Console pane on session start/restart (preserves the
  -- terminal channel — only wipes scrollback).
  clear_console_on_start = true,

  -- Scope names to default-collapse in Scopes. dapui auto-collapses any
  -- scope the adapter marks `expensive`, but codelldb doesn't flag
  -- Registers as expensive even though it's a huge dump.
  collapsed_scopes = { "Registers" },

  -- Dim inactive dapui pane borders so the focused pane is obvious.
  active_window_highlight = true,
})
```

### Chrome bars

When debug mode is active, two 2-row floating bars appear, completely
independent of lualine, heirline, or any other statusline plugin:

**Status bar (top)** shows:
- The `turbo-debug` brand
- Live `dap.status()` progress text
- Session state chip: ` DEBUG · READY ` / ` · RUNNING ` / ` · PAUSED `
  (color-coded via `DiagnosticHint` / `DiagnosticInfo` / `DiagnosticError`)

**Control bar (bottom, above your statusline)** shows:
- Clickable buttons: `(c)ontinue` / `(s)tep` *over* / `(d)escend` *into* /
  `(r)eturn` *out* / `(R)estart` (during session) / `(q) terminate`
- `(?) help` right-anchored
- Italic qualifiers (`over`, `into`, `out`) are inline when width allows;
  auto-dropped on narrow terminals

Both bars:
- Recreate themselves if killed by layout changes (bufferline tabline
  toggles, `wincmd =`, etc.)
- Re-render on every DAP state change (|User DapProgressUpdate|)
- Close cleanly on exit

### Design notes

- **Rounded borders** are on every *floating* window this plugin opens:
  the help popup (`?`), the hover popup (`K`), and the debug-eval popup
  (`E`). Floating windows are the only windows Neovim draws borders around
  in the terminal grid. Splits (the Scopes/Watches/Stacks/Breakpoints/
  Console panes) use the user's `WinSeparator` character — that's a
  terminal-rendering limit, not a plugin choice.

- **No hardcoded colors.** Every highlight links to a standard group
  (`DiagnosticError`, `Function`, `Comment`, `CursorLine`, `Visual`,
  `Search`, `Title`, `Special`, `WinBar`, etc.) so the plugin
  automatically inherits your colorscheme on the fly. Switch themes
  mid-session (or set `colorscheme = "high-contrast"` in `setup()` for
  a dedicated debug theme) and everything re-paints.

- **Emoji** (supplementary-plane, not VS16-dependent) for iconography:
  🔴 🟡 ⭕ 👉 📝 for gutter signs; 🟢 🚀 👣 🔽 🔼 🔄 🛑 for control
  buttons; 🔎 👀 📚 🔴 💻 for pane titles. Colored emoji render
  consistently in modern terminals (Ghostty, Kitty, WezTerm, iTerm)
  without font-dependent rendering quirks.

## Supported Languages

turbo-debug ships adapter configs for 22 languages. You install the adapter
binary (via [mason.nvim](https://github.com/williamboman/mason.nvim), your
package manager, or manually) — turbo-debug handles all the configuration.

| Language | Adapter | Language | Adapter |
|----------|---------|----------|---------|
| Python | debugpy | C# | netcoredbg |
| JavaScript / TS | js-debug | F# | netcoredbg |
| Go | delve | Java | java-debug-adapter |
| C / C++ | codelldb | Kotlin | kotlin-debug |
| Rust | codelldb | PHP | php-debug |
| Swift | codelldb | Ruby | rdbg |
| Zig | codelldb | Elixir | elixir-ls |
| Nim | codelldb | Haskell | haskell-debug-adapter |
| Crystal | codelldb | OCaml | ocamlearlybird |
| Dart / Flutter | dart-debug | R | vscDebugger |
| Bash / Sh | bash-debug-adapter | Lua (Neovim) | osv |

Special treatment:
- **Rust**: pressing `c` runs `cargo build` automatically and picks the
  binary via `vim.ui.select`.
- **Python**: auto-detects virtualenvs (`VIRTUAL_ENV`, `CONDA_PREFIX`,
  `.venv`, `venv`, `env`, `.env`).
- **Dart**: if `flutter` is on PATH, a "Launch Flutter app" configuration
  is added alongside the plain Dart file launch.
- **R**: preflights that the `vscDebugger` R package is installed; silently
  skips registration if missing.

## What This Plugin Actually Does

turbo-debug is **glue**. It does not implement a debugger, a UI framework,
virtual text rendering, or breakpoint persistence. It configures and wires
together these excellent plugins into a single cohesive experience:

| Plugin | What it provides |
|--------|-----------------|
| [nvim-dap](https://github.com/mfussenegger/nvim-dap) | DAP client — the core debug engine |
| [nvim-dap-ui](https://github.com/rcarriga/nvim-dap-ui) | Scopes, stacks, watches, REPL, console UI |
| [nvim-nio](https://github.com/nvim-neotest/nvim-nio) | Async IO (required by nvim-dap-ui) |
| [nvim-dap-virtual-text](https://github.com/theHamsta/nvim-dap-virtual-text) | Inline variable values in source code |
| [persistent-breakpoints.nvim](https://github.com/Weissle/persistent-breakpoints.nvim) | Breakpoints that survive restarts |

All five are loaded automatically via `vim.pack.add`. You never declare them.

Adapter configurations are inlined from the work of these projects (no
runtime dependency, we just studied their configs and wrote plain Lua tables):

- [nvim-dap-python](https://github.com/mfussenegger/nvim-dap-python)
- [nvim-dap-go](https://github.com/leoluz/nvim-dap-go)
- [nvim-dap-vscode-js](https://github.com/mxsdev/nvim-dap-vscode-js)
- [nvim-dap-lldb](https://github.com/julianolf/nvim-dap-lldb)
- [nvim-dap-cs](https://github.com/NicholasMata/nvim-dap-cs)
- [nvim-dap-ruby](https://github.com/suketa/nvim-dap-ruby)
- [nvim-dap-kotlin](https://github.com/Mgenuit/nvim-dap-kotlin)

## License

MIT