mode: enter/exit debug mode with keybinding lifecycle

lua/tiny-debugger/init.lua

@@ -1,3 +1,18 @@
+local config = require("tiny-debugger.config")
+local mode = require("tiny-debugger.mode")
+
 local M = {}
 
+function M.setup(opts)
+  config.merge(opts)
+end
+
+function M.toggle()
+  mode.toggle()
+end
+
+function M.active()
+  return mode.is_active()
+end
+
 return M

lua/tiny-debugger/mode.lua

@@ -0,0 +1,129 @@
+local config = require("tiny-debugger.config")
+
+local M = {}
+
+local active = false
+local stashed_maps = {}
+
+local function stash_mapping(buf, lhs)
+  local maps = vim.api.nvim_buf_get_keymap(buf, "n")
+  for _, map in ipairs(maps) do
+    if map.lhs == lhs then
+      stashed_maps[lhs] = map
+      return
+    end
+  end
+  stashed_maps[lhs] = nil
+end
+
+local function restore_mapping(buf, lhs)
+  local map = stashed_maps[lhs]
+  if map then
+    local rhs = map.rhs or map.callback
+    if rhs then
+      vim.keymap.set("n", lhs, rhs, {
+        buffer = buf,
+        silent = map.silent == 1,
+        noremap = map.noremap == 1,
+        expr = map.expr == 1,
+        desc = map.desc,
+      })
+    end
+  else
+    pcall(vim.keymap.del, "n", lhs, { buffer = buf })
+  end
+end
+
+-- actions table: key name → function
+-- populated by other modules via M.register_action
+local actions = {}
+
+function M.register_action(name, fn)
+  actions[name] = fn
+end
+
+-- default actions that map directly to dap calls
+local function setup_default_actions()
+  local dap = require("dap")
+  actions.continue = function() dap.continue() end
+  actions.step_over = function() dap.step_over() end
+  actions.step_into = function() dap.step_into() end
+  actions.step_out = function() dap.step_out() end
+  actions.run_to_cursor = function() dap.run_to_cursor() end
+  actions.terminate = function()
+    dap.terminate()
+    M.exit()
+  end
+  actions.restart = function() dap.restart() end
+end
+
+local function set_keymaps(buf)
+  local keys = config.opts.keys
+  for name, key in pairs(keys) do
+    if key and actions[name] then
+      stash_mapping(buf, key)
+      vim.keymap.set("n", key, actions[name], { buffer = buf, silent = true, desc = "tiny-debugger: " .. name })
+    end
+  end
+end
+
+local function clear_keymaps(buf)
+  local keys = config.opts.keys
+  for name, key in pairs(keys) do
+    if key and actions[name] then
+      pcall(vim.keymap.del, "n", key, { buffer = buf })
+      restore_mapping(buf, key)
+    end
+  end
+  stashed_maps = {}
+end
+
+local saved_cursor_hl = nil
+
+local function set_cursor_highlight()
+  saved_cursor_hl = vim.api.nvim_get_hl(0, { name = "Cursor" })
+  vim.api.nvim_set_hl(0, "Cursor", { bg = "#ff6600", fg = "#000000" })
+end
+
+local function restore_cursor_highlight()
+  if saved_cursor_hl then
+    vim.api.nvim_set_hl(0, "Cursor", saved_cursor_hl)
+    saved_cursor_hl = nil
+  else
+    vim.api.nvim_set_hl(0, "Cursor", {})
+  end
+end
+
+function M.enter()
+  if active then return end
+  active = true
+
+  setup_default_actions()
+
+  local buf = vim.api.nvim_get_current_buf()
+  set_keymaps(buf)
+  set_cursor_highlight()
+end
+
+function M.exit()
+  if not active then return end
+  active = false
+
+  local buf = vim.api.nvim_get_current_buf()
+  clear_keymaps(buf)
+  restore_cursor_highlight()
+end
+
+function M.toggle()
+  if active then
+    M.exit()
+  else
+    M.enter()
+  end
+end
+
+function M.is_active()
+  return active
+end
+
+return M

plugin/tiny-debugger.lua

@@ -12,3 +12,8 @@ vim.pack.add({ "rcarriga/nvim-dap-ui" })
 vim.pack.add({ "nvim-neotest/nvim-nio" })
 vim.pack.add({ "theHamsta/nvim-dap-virtual-text" })
 vim.pack.add({ "Weissle/persistent-breakpoints.nvim" })
+
+-- toggle debug mode
+vim.keymap.set("n", "<leader>d", function()
+  require("tiny-debugger").toggle()
+end, { silent = true, desc = "tiny-debugger: toggle debug mode" })

tests/test_keys.lua

@@ -0,0 +1,28 @@
+-- tests for keybinding stash/restore
+local td = require("tiny-debugger")
+
+local function assert_eq(a, b, msg)
+  if a ~= b then
+    error(string.format("FAIL: %s — expected %s, got %s", msg, vim.inspect(b), vim.inspect(a)))
+  end
+end
+
+-- set a custom mapping for 'c'
+local custom_called = false
+vim.keymap.set("n", "c", function() custom_called = true end, { buffer = 0, desc = "custom c" })
+
+-- verify custom mapping exists
+local maparg = vim.fn.maparg("c", "n", false, true)
+assert_eq(maparg.desc, "custom c", "custom mapping exists before enter")
+
+-- enter debug mode — should override 'c'
+td.toggle()
+maparg = vim.fn.maparg("c", "n", false, true)
+assert_eq(maparg.desc, "tiny-debugger: continue", "c overridden in debug mode")
+
+-- exit debug mode — should restore custom 'c'
+td.toggle()
+maparg = vim.fn.maparg("c", "n", false, true)
+assert_eq(maparg.desc, "custom c", "custom mapping restored after exit")
+
+print("ALL KEY STASH/RESTORE TESTS PASSED")

tests/test_mode.lua

@@ -0,0 +1,42 @@
+-- tests for debug mode enter/exit
+local td = require("tiny-debugger")
+local mode = require("tiny-debugger.mode")
+
+local function assert_eq(a, b, msg)
+  if a ~= b then
+    error(string.format("FAIL: %s — expected %s, got %s", msg, vim.inspect(b), vim.inspect(a)))
+  end
+end
+
+local function has_buf_map(key)
+  local maps = vim.api.nvim_buf_get_keymap(0, "n")
+  for _, m in ipairs(maps) do
+    if m.lhs == key then return true end
+  end
+  return false
+end
+
+-- test 1: starts inactive
+assert_eq(td.active(), false, "starts inactive")
+
+-- test 2: toggle enters debug mode
+td.toggle()
+assert_eq(td.active(), true, "active after toggle")
+
+-- test 3: keymaps are set
+assert_eq(has_buf_map("c"), true, "continue key mapped")
+assert_eq(has_buf_map("s"), true, "step_over key mapped")
+assert_eq(has_buf_map("d"), true, "step_into key mapped")
+assert_eq(has_buf_map("r"), true, "step_out key mapped")
+assert_eq(has_buf_map("q"), true, "terminate key mapped")
+
+-- test 4: toggle exits debug mode
+td.toggle()
+assert_eq(td.active(), false, "inactive after second toggle")
+
+-- test 5: keymaps are removed
+assert_eq(has_buf_map("c"), false, "continue key removed")
+assert_eq(has_buf_map("s"), false, "step_over key removed")
+assert_eq(has_buf_map("q"), false, "terminate key removed")
+
+print("ALL MODE TESTS PASSED")