feat(nvim): opt-in autoreload of buffers changed outside Neovim

2 files changed, 58 insertions, 1 deletions

diff --git a/plugin/50-autoreload.lua b/plugin/50-autoreload.lua
new file mode 100644
index 0000000..765c137
--- /dev/null
+++ b/plugin/50-autoreload.lua
@@ -0,0 +1,56 @@
+--[[ 50-autoreload.lua — opt-in reloading of buffers changed outside Neovim.
+
+When enabled, buffers whose file changed on disk are reloaded silently, in one batch, on focus / idle /
+buffer-enter — no per-file change prompt. Conflicts (the buffer was also edited in Neovim) and
+deletions still defer to Neovim's usual prompt. Off by default; the state lives in
+`vim.g.autoreload` and shows as the `+R` flag in the statusline (see 50-color.lua).
+
+User commands:
+  `AutoreloadToggle`:  toggle disk-change autoreload for this Neovim instance
+]]
+
+vim.g.autoreload = false
+
+-- Re-stat every loaded buffer in one pass; the FileChangedShell handler below decides per buffer.
+local function check_all_buffers()
+	if vim.g.autoreload then
+		vim.cmd.checktime() -- no argument → all loaded buffers at once
+	end
+end
+
+vim.api.nvim_create_autocmd(
+	{ "FocusGained", "BufEnter", "CursorHold", "CursorHoldI", "TermLeave" },
+	{
+		group = vim.g.dotfiles.augroup,
+		callback = check_all_buffers,
+	}
+)
+
+--[[ Decide what happens when Neovim notices a file changed under it. While autoreload is on, a plain
+on-disk change reloads the buffer with no prompt (batched, since `checktime` fires this for each
+changed buffer in a single pass); conflicts and deletions fall back to `ask`. While off, everything
+falls back to `ask`, i.e. Neovim's default handling. See <nvim-help://v:fcs_choice>. ]]
+vim.api.nvim_create_autocmd("FileChangedShell", {
+	group = vim.g.dotfiles.augroup,
+	callback = function()
+		if vim.g.autoreload and vim.v.fcs_reason == "changed" then
+			vim.v.fcs_choice = "reload"
+		else
+			vim.v.fcs_choice = "ask"
+		end
+	end,
+})
+
+-- Flip autoreload for this instance; check immediately when turning it on so pending changes catch up.
+local function toggle_autoreload()
+	vim.g.autoreload = not vim.g.autoreload
+	vim.notify("Buffer autoreload " .. (vim.g.autoreload and "enabled" or "disabled"))
+	check_all_buffers()
+	vim.cmd.redrawstatus()
+end
+
+vim.api.nvim_create_user_command(
+	"AutoreloadToggle",
+	toggle_autoreload,
+	{ desc = "Toggle buffer autoreload" }
+)
diff --git a/plugin/50-color.lua b/plugin/50-color.lua
index 5eb03b3..ede41ee 100644
--- a/plugin/50-color.lua
+++ b/plugin/50-color.lua
@@ -84,10 +84,11 @@ local function spell_status()
 end
 
 -- Custom status flags: "+F" when formatting is on for the buffer, "+H" when LSP inlay hints are on,
--- followed by the spell flag.
+-- "+R" when disk-change autoreload is enabled (see 50-autoreload.lua), followed by the spell flag.
 local function statuses()
 	return (vim.b.format and "+F" or "")
 		.. (vim.lsp.inlay_hint.is_enabled({ bufnr = 0 }) and "+H" or "")
+		.. (vim.g.autoreload and "+R" or "")
 		.. (vim.o.spell and spell_status() or "")
 end