lua/config/git-worktree.lua

@@ -1,9 +1,17 @@
 -- Worktree-aware git project switching.
 --
--- Turns a plain single-worktree checkout into a worktree-style layout where
--- every local branch is checked out in its own linked worktree, and provides a
--- Telescope picker to switch between branches (creating / fetching worktrees
--- on demand).
+-- Two layouts are supported, detected automatically from `git worktree list`:
+--
+--   • Bare-home layout (created by `convert`): the repo's main directory IS a
+--     bare repo (no working tree) and every local branch is checked out in a
+--     linked worktree under `<home>/.worktrees/<branch>`. nvim can be opened
+--     in the bare home itself to switch branches / create worktrees.
+--   • Plain layout: the usual single-checkout repo, where switching between
+--     branches materialises linked worktrees in `<parent>/.worktrees/…`.
+--
+-- The Telescope picker switches between branches (creating / fetching
+-- worktrees on demand) and offers creating a new branch from the worktree
+-- that is currently open.
 --
 -- Loaded lazily: the module is only required when a keymap, command or the
 -- explorer title calls into it (see lua/plugins/worktree.lua and
@@ -17,9 +25,12 @@ local M = {}
 
 ---@class git-worktree.Opts
 M.config = {
-  -- Where linked worktrees are created. Defaults to `<parent>/.worktrees/<project>/<branch>`
-  -- (e.g. `~/src/.worktrees/desi_explorer/feat-api_connection`). Branch names
-  -- are sanitised so `/` maps to `-`: any valid branch becomes a valid path.
+  -- Where linked worktrees are created for a non-bare (plain) checkout.
+  -- Defaults to `<parent>/.worktrees/<project>/<branch>` (e.g.
+  -- `~/src/.worktrees/desi_explorer/feat-api_connection`). For the bare-home
+  -- layout the worktrees always live under `<home>/.worktrees/<branch>` instead
+  -- (see git-worktree.worktree_dir). Branch names are sanitised so `/` maps to
+  -- `-`: any valid branch becomes a valid path.
   worktree_dir = function(branch, repo)
     local parent = vim.fs.dirname(repo)
     local project = vim.fs.basename(repo)
@@ -76,20 +87,56 @@ local function git_async(args, cb)
   end)
 end
 
----Absolute path to the git root of the cwd, or nil when not in a repo.
+---Normalise a path: make it absolute and drop trailing slashes.
+---@param p string
+---@return string
+local function norm(p)
+  return vim.fn.fnamemodify(p, ":p"):gsub("/+$", "")
+end
+
+---Absolute path to the git root of `cwd`: the top-level of the worktree being
+---worked in. Returns nil when `cwd` is not inside a working tree (which is
+---normally the case when nvim sits in a bare repo home).
+---@param cwd? string
 ---@return string?
-function M.git_root()
-  local res = git({ "rev-parse", "--show-toplevel" })
+function M.git_root(cwd)
+  local res = git({ "rev-parse", "--show-toplevel" }, { cwd = cwd })
   if res.code ~= 0 or res.stdout == "" then
     return nil
   end
   return res.stdout -- already absolute; drop any trailing slash
 end
 
----Name of the branch checked out in the current worktree (nil when detached).
+---Root of the whole worktree layout for `cwd`: the bare home directory when the
+---repo uses the bare-home layout, or the main (plain) checkout otherwise.
+---Both are the first `worktree` entry of `git worktree list --porcelain`.
+---@param cwd? string
 ---@return string?
-function M.current_branch()
-  local res = git({ "symbolic-ref", "-q", "--short", "HEAD" })
+function M.home(cwd)
+  local res = git({ "worktree", "list", "--porcelain" }, { cwd = cwd })
+  if res.code ~= 0 then
+    return nil
+  end
+  local path = res.stdout:match("^worktree ([^\n]+)")
+  if not path then
+    return nil
+  end
+  return norm(path)
+end
+
+---Whether the repo at `cwd` is bare (i.e. it has no working tree).
+---@param cwd? string
+---@return boolean
+function M.is_bare(cwd)
+  local res = git({ "rev-parse", "--is-bare-repository" }, { cwd = cwd })
+  return res.code == 0 and res.stdout == "true"
+end
+
+---Name of the branch checked out in the current worktree (nil when detached).
+---@param cwd? string
+---@return string?
+function M.current_branch(cwd)
+  local res = git({ "symbolic-ref", "-q", "--short", "HEAD" }, { cwd = cwd })
   if res.code ~= 0 then
     return nil
   end
@@ -104,9 +151,10 @@ end
 ---@field locked? boolean
 
 ---Parse `git worktree list --porcelain` into records.
+---@param cwd? string
 ---@return git-worktree.Worktree[]
-function M.worktrees()
-  local res = git({ "worktree", "list", "--porcelain" })
+function M.worktrees(cwd)
+  local res = git({ "worktree", "list", "--porcelain" }, { cwd = cwd })
   if res.code ~= 0 then
     return {}
   end
@@ -116,7 +164,7 @@ function M.worktrees()
     if line == "" then
       cur = nil
     elseif line:sub(1, 8) == "worktree" then
-      cur = { path = vim.fn.fnamemodify(line:sub(10), ":p"):gsub("/+$", "") }
+      cur = { path = norm(line:sub(10)) }
       table.insert(wts, cur)
     elseif line:sub(1, 6) == "branch" and cur then
       cur.branch = line:sub(8):gsub("^refs/heads/", "")
@@ -132,9 +180,10 @@ function M.worktrees()
 end
 
 ---Names of all local branches.
+---@param cwd? string
 ---@return string[]
-function M.local_branches()
-  local res = git({ "for-each-ref", "--format=%(refname:short)", "refs/heads" })
+function M.local_branches(cwd)
+  local res = git({ "for-each-ref", "--format=%(refname:short)", "refs/heads" }, { cwd = cwd })
   if res.code ~= 0 then
     return {}
   end
@@ -183,7 +232,10 @@ function M.branches()
     end
   end
 
-  local current = M.current_branch()
+  -- Current branch = the one checked out in the worktree we are sitting in. A
+  -- bare home has no working tree, so nothing is "current" there (symbolic-ref
+  -- would just report the bare repo's default HEAD).
+  local current = M.git_root() and M.current_branch() or nil
 
   -- Preserve for-each-ref's date ordering (newest first) across both namespaces
   local ordered = {} ---@type {name: string, info: string[], remote: boolean}[]
@@ -247,16 +299,23 @@ end
 -- Worktree operations
 -- ─────────────────────────────────────────────────────────────────────────────
 
----Target directory for a branch's linked worktree.
+---Target directory for a branch's linked worktree, rooted at the layout home.
+---For a bare home the linked worktrees live inside it, under `.worktrees/`; for
+---a plain checkout they stay next to it (`.worktrees/` beside the repo).
 ---@param branch string
----@param repo string git root
+---@param home string worktree-layout home directory (see M.home())
 ---@return string
-function M.worktree_dir(branch, repo)
-  return (M.config.worktree_dir or function(b, r)
+function M.worktree_dir(branch, home)
+  if M.is_bare(home) then
+    return vim.fs.joinpath(home, ".worktrees", (branch:gsub("/", "-")))
+  end
+  local fn = M.config.worktree_dir
+    or function(b, r)
       local parent = vim.fs.dirname(r)
       local project = vim.fs.basename(r)
       return parent .. "/.worktrees/" .. project .. "/" .. b:gsub("/", "-")
-  end)(branch, repo)
+    end
+  return fn(branch, home)
 end
 
 ---Materialise `entry` as a linked worktree (creating a tracking local branch
@@ -267,11 +326,11 @@ function M.ensure_worktree(entry)
   if entry.worktree then
     return { ok = true, path = entry.worktree, err = nil }
   end
-  local repo = M.git_root()
-  if not repo then
+  local home = M.home()
+  if not home then
     return { ok = false, path = nil, err = "Not inside a git repo" }
   end
-  local dir = M.worktree_dir(entry.name, repo)
+  local dir = M.worktree_dir(entry.name, home)
   if vim.fn.isdirectory(dir) == 1 then
     return { ok = false, path = nil, err = "Target exists and is not a registered worktree: " .. dir }
   end
@@ -301,8 +360,8 @@ function M.remove_entry(entry)
     return
   end
   if entry.worktree then
-    if entry.worktree == M.git_root() then
-      vim.notify("Cannot remove the main worktree (" .. entry.worktree .. ")", vim.log.levels.WARN)
+    if entry.worktree == M.home() then
+      vim.notify("Cannot remove the home worktree (" .. entry.worktree .. ")", vim.log.levels.WARN)
       return
     end
     local choice = vim.fn.confirm(("Remove worktree for %s?\n%s"):format(entry.name, entry.worktree), "&Yes\n&No", 2)
@@ -369,11 +428,11 @@ function M.new_worktree(entry)
       if base_name ~= nil and (base_name == "" or base_name:sub(1, 1) == ":") then
         base_name = nil -- empty input → default
       end
-      local repo = M.git_root()
-      if not repo then
+      local home = M.home()
+      if not home then
         return
       end
-      local dir = M.worktree_dir(name, repo)
+      local dir = M.worktree_dir(name, home)
       if vim.fn.isdirectory(dir) == 1 then
         vim.notify("Target already exists: " .. dir, vim.log.levels.ERROR)
         return
@@ -458,65 +517,81 @@ function M.switch(entry)
   M.open_worktree(res.path, entry.name)
 end
 
----Convert the current repo from a single-worktree checkout into a worktree
----layout: every local branch gets its own linked worktree, so no branch that
----was on the machine is lost. The branch in `keep` (default: the current one)
----stays checked out in the main worktree.
----@param opts? {keep?: string}
+---Convert the current repo into a bare-home worktree layout:
+---
+---  1. The whole directory (working tree + `.git`) is copied to a temp backup.
+---  2. The current directory (which must hold the repo's `.git`) is turned into
+---     a bare repo — it becomes the layout's home with no working tree.
+---  3. Every local branch is materialised as a linked worktree under
+---     `<home>/.worktrees/<branch>`, so nvim can be opened in the bare home and
+---     switch branches / create worktrees from there.
+---
+---Any linked worktrees that already exist (e.g. from an earlier, legacy
+---conversion in a sibling `.worktrees/` dir) are re-anchored and kept.
+---
+---Must be run from the repo's main checkout (the directory holding `.git`),
+---on a repo that is not already bare.
+---@param opts? {keep?: string} `keep` (default: the previously checked-out
+---branch) is re-opened after conversion
 function M.convert(opts)
   opts = opts or {}
-  local repo = M.git_root()
-  if not repo then
+  local cwd = norm(vim.uv.cwd())
+  if M.is_bare(cwd) then
+    vim.notify("Already a bare repo — nothing to convert", vim.log.levels.INFO)
+    return
+  end
+  local root = M.git_root()
+  if not root then
     vim.notify("Not inside a git repo", vim.log.levels.ERROR)
     return
   end
-  local project = vim.fs.basename(repo)
-  local cur = M.current_branch()
-  local keep = opts.keep or cur
-  if not keep then
+  if norm(root) ~= cwd then
     vim.notify(
-      ("Detached HEAD — pass --keep=<branch> to choose which branch stays at %s"):format(repo),
+      ("Convert must run from the repo's main directory (where `.git` lives).\nCurrent dir: %s\nRepo root: %s"):format(
+        cwd,
+        root
+      ),
       vim.log.levels.WARN
     )
     return
   end
-  if keep ~= cur then
-    local res = git({ "switch", "--", keep })
-    if res.code ~= 0 then
-      vim.notify(("Could not switch to --keep branch %s:\n%s"):format(keep, res.stderr), vim.log.levels.ERROR)
-      return
-    end
-    cur = keep
-  end
-
-  local branches = M.local_branches()
-  local todo = {}
-  for _, b in ipairs(branches) do
-    if b ~= keep then
-      todo[#todo + 1] = b
-    end
-  end
-  if #todo == 0 then
+  local git_entry = cwd .. "/.git"
+  if vim.fn.isdirectory(git_entry) ~= 1 then
+    if vim.fn.filereadable(git_entry) == 1 then
       vim.notify(
-      ("%s only has local branch %s — nothing else to materialise"):format(project, keep),
-      vim.log.levels.INFO
+        "You are inside a linked worktree of an already-converted repo.\n"
+          .. "Open nvim in its bare home ("
+          .. (M.home() or "?")
+          .. ") instead",
+        vim.log.levels.WARN
       )
+    else
+      vim.notify("Expected a `.git` directory in " .. cwd .. " — nothing to convert", vim.log.levels.ERROR)
+    end
     return
   end
 
-  -- Branches already checked out somewhere (idempotent re-runs)
-  local existing = {} ---@type table<string, string>
-  for _, wt in ipairs(M.worktrees()) do
-    if wt.branch then
-      existing[wt.branch] = wt.path
-    end
+  local project = vim.fs.basename(cwd)
+  local branches = M.local_branches()
+  if #branches == 0 then
+    vim.notify(("%s has no local branches to materialise"):format(project), vim.log.levels.WARN)
+    return
   end
+  local cur = M.current_branch()
 
-  -- Confirm if the main worktree is dirty (only affects `--keep` switching)
-  local dirty = git({ "status", "--porcelain", "--untracked-files=no" })
-  if dirty.code == 0 and dirty.stdout ~= "" then
+  local dirty = git({ "status", "--porcelain" })
+  local dirty_msg = dirty.code == 0
+      and dirty.stdout ~= ""
+      and "\nUncommitted / untracked files are only preserved in the backup.\n"
+    or ""
   local choice = vim.fn.confirm(
-      ("Uncommitted changes in %s.\nConvert anyway? (they stay in the %s worktree)"):format(project, keep),
+    ("Turn %s into a bare home repo?\n"):format(project)
+      .. "\n"
+      .. ("  %s  becomes a bare repo (no working tree)\n"):format(cwd)
+      .. ("  %s/.worktrees/<branch>  keeps one worktree per local branch\n"):format(cwd)
+      .. "  the whole repo is copied to a temp backup first\n"
+      .. dirty_msg
+      .. "\nProceed?",
     "&Yes\n&No",
     2
   )
@@ -524,18 +599,70 @@ function M.convert(opts)
     vim.notify("Convert aborted", vim.log.levels.INFO)
     return
   end
+
+  -- 1. Full backup (working tree + .git). nvim's own temp dir is wiped on exit,
+  -- so use the OS tmp dir instead so the backup survives the session.
+  local tmp = vim.env.TMPDIR ~= nil and vim.env.TMPDIR ~= "" and vim.env.TMPDIR or "/tmp"
+  local backup = vim.fs.joinpath(tmp, project .. "-worktree-backup-" .. os.time())
+  local bump = 1
+  while vim.fn.isdirectory(backup) == 1 or vim.fn.filereadable(backup) == 1 do
+    bump = bump + 1
+    backup = vim.fs.joinpath(tmp, project .. "-worktree-backup-" .. os.time() .. "-" .. bump)
+  end
+  vim.fn.mkdir(backup, "p")
+  vim.notify(("Backing up %s to %s …"):format(project, backup), vim.log.levels.INFO)
+  local cp = vim.system({ "cp", "-a", cwd .. "/.", backup .. "/" }, { text = true, timeout = 300000 }):wait()
+  if cp.code ~= 0 then
+    vim.notify(("Backup failed:\n%s\nConversion aborted"):format(cp.stderr), vim.log.levels.ERROR)
+    return
   end
 
-  local created, skipped, errors = {}, {}, {}
-  for _, b in ipairs(todo) do
+  -- 2. Mark the repo bare while `.git` is still discoverable. Drop any stale
+  -- `core.worktree` so git-dir discovery keys off the directory itself.
+  local bare = git({ "config", "core.bare", "true" })
+  if bare.code ~= 0 then
+    vim.notify("Could not mark the repo as bare:\n" .. bare.stderr, vim.log.levels.ERROR)
+    return
+  end
+  git({ "config", "--unset-all", "core.worktree" })
+
+  -- 3. Drop the old working tree, then hoist `.git/*` so the directory itself
+  -- becomes the bare git dir (backed up above, so nothing is lost).
+  local entries = {}
+  for e in vim.fs.dir(cwd) do
+    entries[#entries + 1] = e
+  end
+  for _, e in ipairs(entries) do
+    if e ~= ".git" then
+      vim.fn.delete(cwd .. "/" .. e, "rf")
+    end
+  end
+  for e in vim.fs.dir(cwd .. "/.git") do
+    vim.fn.rename(cwd .. "/.git/" .. e, cwd .. "/" .. e)
+  end
+  vim.fn.delete(cwd .. "/.git", "rf")
+
+  -- 4. Re-anchor any linked worktrees (from a previous layout) whose paths may
+  -- no longer point at the moved admin dirs.
+  git({ "worktree", "repair" })
+
+  -- 5. Materialise every local branch as a linked worktree under the bare home.
+  local existing = {} ---@type table<string, string>
+  for _, wt in ipairs(M.worktrees()) do
+    if wt.branch then
+      existing[wt.branch] = wt.path
+    end
+  end
+  vim.fn.mkdir(cwd .. "/.worktrees", "p")
+  local created, kept, errors = {}, {}, {}
+  for _, b in ipairs(branches) do
     if existing[b] then
-      skipped[#skipped + 1] = { b, existing[b] }
+      kept[#kept + 1] = { b, existing[b] }
     else
-      local dir = M.worktree_dir(b, repo)
+      local dir = M.worktree_dir(b, cwd)
       if vim.fn.isdirectory(dir) == 1 then
         errors[#errors + 1] = { b, "target exists and is not a worktree: " .. dir }
       else
-        vim.fn.mkdir(vim.fn.fnamemodify(dir, ":h"), "p")
         local res = git({ "worktree", "add", dir, "--", b })
         if res.code == 0 then
           created[#created + 1] = { b, dir }
@@ -546,19 +673,21 @@ function M.convert(opts)
     end
   end
 
-  local lines = { ("%s now uses a worktree layout (%s stays at the main worktree)"):format(project, keep) }
+  -- 6. Report; then move into the branch that was checked out before the
+  -- conversion.
+  local lines = { ("%s is now a bare home at %s (%d branch worktrees)"):format(project, cwd, #branches) }
   if #created > 0 then
     lines[#lines + 1] = "Created " .. #created .. " worktree(s):"
     for _, c in ipairs(created) do
       lines[#lines + 1] = "  " .. c[1] .. " → " .. c[2]
     end
   end
-  if #skipped > 0 then
-    lines[#lines + 1] = "Already materialised: "
+  if #kept > 0 then
+    lines[#lines + 1] = "Already checked out: "
       .. table.concat(
         vim.tbl_map(function(e)
           return e[1]
-        end, skipped),
+        end, kept),
         ", "
       )
   end
@@ -570,7 +699,25 @@ function M.convert(opts)
       "\n"
     ), vim.log.levels.WARN)
   end
-  vim.notify(table.concat(lines, "\n") .. "\nSwitch branches anytime with <leader>gw", vim.log.levels.INFO)
+  lines[#lines + 1] = "Backup: " .. backup
+  lines[#lines + 1] = "Open nvim in " .. cwd .. " and switch branches with <leader>gw"
+  vim.notify(table.concat(lines, "\n"), vim.log.levels.INFO)
+
+  local open = opts.keep or cur
+  if open then
+    local dir = existing[open]
+    if not dir then
+      for _, c in ipairs(created) do
+        if c[1] == open then
+          dir = c[2]
+          break
+        end
+      end
+    end
+    if dir then
+      M.open_worktree(dir, open)
+    end
+  end
 end
 
 ---Parse `GitWorktreeConvert` command args (--keep=<branch>).
@@ -586,18 +733,25 @@ function M.convert_prompt(fargs)
   M.convert({ keep = keep })
 end
 
----Title for the explorer window: current project + checked-out branch.
+---Title for the explorer window: project + layout home + current branch.
 ---@param path? string dir to label (defaults to cwd)
 ---@return string?
 function M.explorer_title(path)
   local cwd = path or vim.uv.cwd()
-  local repo = git({ "rev-parse", "--show-toplevel" }, { cwd = cwd })
-  if repo.code ~= 0 or repo.stdout == "" then
-    return nil -- not a git dir; let the explorer use its default title
+  local home = M.home(cwd)
+  if not home then
+    return nil -- not a git repo; let the explorer use its default title
   end
-  local project = vim.fs.basename(repo.stdout:gsub("/+$", ""))
+  local project = vim.fs.basename(home)
+  local branch_label
+  if M.git_root(cwd) then
     local branch = git({ "symbolic-ref", "-q", "--short", "HEAD" }, { cwd = cwd })
-  local branch_label = branch.code == 0 and branch.stdout or "detached"
+    branch_label = branch.code == 0 and branch.stdout or "detached"
+  elseif M.is_bare(cwd) then
+    branch_label = "bare home"
+  else
+    return nil
+  end
   local wts = git({ "worktree", "list", "--porcelain" }, { cwd = cwd })
   local count = 0
   if wts.code == 0 then
@@ -620,7 +774,7 @@ end
 ---@param opts? table telescope opts
 function M.pick(kind, opts)
   opts = opts or {}
-  local repo = M.git_root()
+  local repo = M.home()
   if not repo then
     vim.notify("Not inside a git repo — open nvim from a project to switch branches", vim.log.levels.ERROR)
     return
@@ -668,14 +822,22 @@ function M.pick(kind, opts)
 
     if kind == "worktree" then
       local wts = M.worktrees()
+      local cur_wt = M.git_root()
       for _, wt in ipairs(wts) do
-        local label = wt.branch or ("(detached " .. (wt.head or "") .. ")")
+        local label
+        if wt.branch then
+          label = wt.branch
+        elseif wt.path == repo then
+          label = project .. " (bare home)"
+        else
+          label = "(bare " .. (wt.head or "") .. ")"
+        end
         items[#items + 1] = {
           name = label,
           worktree = wt.path,
           remote = nil,
           remote_only = false,
-          current = wt.path == repo,
+          current = wt.path == repo or wt.path == cur_wt,
         }
       end
       local d = displayer_for(items)
@@ -810,7 +972,11 @@ function M.pick(kind, opts)
         remap({ "i", "n" }, "<c-n>", function()
           actions.close(prompt_bufnr)
           M.new_worktree(selected())
-        end, "New branch worktree")
+        end, "New branch worktree (from selected)")
+        remap({ "i", "n" }, "<c-b>", function()
+          actions.close(prompt_bufnr)
+          M.pick("worktree")
+        end, "Switch to worktree picker")
       else
         remap({ "i", "n" }, "<c-d>", function()
           if selected() then
@@ -819,6 +985,14 @@ function M.pick(kind, opts)
             reopen()
           end
         end, "Remove worktree")
+        remap({ "i", "n" }, "<c-n>", function()
+          actions.close(prompt_bufnr)
+          M.new_worktree()
+        end, "New branch worktree (from current)")
+        remap({ "i", "n" }, "<c-b>", function()
+          actions.close(prompt_bufnr)
+          M.pick("branch")
+        end, "Switch to branch picker")
       end
       return true
     end,

lua/plugins/worktree.lua

@@ -24,6 +24,13 @@ return {
         end,
         desc = "Git Worktrees",
       },
+      {
+        "<leader>gN",
+        function()
+          require("config.git-worktree").new_worktree()
+        end,
+        desc = "New branch worktree (from current)",
+      },
       {
         "<leader>gC",
         function()