From c9d4b362cba6f4b4cfdb82a40f8fc652415786d7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sindre=20T=2E=20Str=C3=B8m?= <sindrets@gmail.com>
Date: Wed, 24 Mar 2021 22:55:52 +0100
Subject: [PATCH 1/4] feat: Implemented optional grouping of empty dirs.

Grouping is controlled by the setting `vim.g.nvim_tree_group_empty`.
---
 lua/nvim-tree.lua          |  2 +-
 lua/nvim-tree/fs.lua       |  4 +++
 lua/nvim-tree/lib.lua      | 16 ++++++++---
 lua/nvim-tree/populate.lua | 58 ++++++++++++++++++++++++++++++++++++--
 lua/nvim-tree/renderer.lua | 14 ++++++---
 5 files changed, 82 insertions(+), 12 deletions(-)

diff --git a/lua/nvim-tree.lua b/lua/nvim-tree.lua
index ccf3dd619e1..b85183c4c58 100644
--- a/lua/nvim-tree.lua
+++ b/lua/nvim-tree.lua
@@ -95,7 +95,7 @@ function M.on_keypress(mode)
   if node.name == ".." then
     return lib.change_dir("..")
   elseif mode == "cd" and node.entries ~= nil then
-    return lib.change_dir(node.absolute_path)
+    return lib.change_dir(lib.get_last_group_node(node).absolute_path)
   elseif mode == "cd" then
     return
   end
diff --git a/lua/nvim-tree/fs.lua b/lua/nvim-tree/fs.lua
index 22cad45dd5b..db1283b0174 100644
--- a/lua/nvim-tree/fs.lua
+++ b/lua/nvim-tree/fs.lua
@@ -3,6 +3,7 @@ local luv = vim.loop
 local open_mode = luv.constants.O_CREAT + luv.constants.O_WRONLY + luv.constants.O_TRUNC
 
 local utils = require'nvim-tree.utils'
+local lib = require'nvim-tree.lib'
 local M = {}
 local clipboard = {
   move = {},
@@ -41,6 +42,7 @@ local function get_num_entries(iter)
 end
 
 function M.create(node)
+  node = lib.get_last_group_node(node)
   if node.name == '..' then return end
 
   local add_into
@@ -168,6 +170,7 @@ local function do_single_paste(source, dest, action_type, action_fn)
 end
 
 local function do_paste(node, action_type, action_fn)
+  node = lib.get_last_group_node(node)
   if node.name == '..' then return end
   local clip = clipboard[action_type]
   if #clip == 0 then return end
@@ -242,6 +245,7 @@ end
 
 function M.rename(with_sub)
   return function(node)
+    node = lib.get_last_group_node(node)
     if node.name == '..' then return end
 
     local namelen = node.name:len()
diff --git a/lua/nvim-tree/lib.lua b/lua/nvim-tree/lib.lua
index 37b7179b34e..03f435e1fad 100644
--- a/lua/nvim-tree/lib.lua
+++ b/lua/nvim-tree/lib.lua
@@ -46,7 +46,7 @@ M.Tree = {
 
 function M.init(with_open, with_render)
   M.Tree.cwd = luv.cwd()
-  populate(M.Tree.entries, M.Tree.cwd, M.Tree)
+  populate(M.Tree.entries, M.Tree.cwd)
 
   local stat = luv.fs_stat(M.Tree.cwd)
   M.Tree.last_modified = stat.mtime.sec
@@ -91,13 +91,21 @@ function M.get_node_at_cursor()
   return get_node_at_line(line)(M.Tree.entries)
 end
 
+function M.get_last_group_node(node)
+  local next = node
+  while next.group_next do
+    next = next.group_next
+  end
+  return next
+end
+
 function M.unroll_dir(node)
   node.open = not node.open
   if node.has_children then node.has_children = false end
   if #node.entries > 0 then
     renderer.draw(M.Tree, true)
   else
-    populate(node.entries, node.link_to or node.absolute_path)
+    populate(node.entries, node.link_to or node.absolute_path, node)
     renderer.draw(M.Tree, true)
   end
 end
@@ -113,7 +121,7 @@ end
 
 -- TODO update only entries where directory has changed
 local function refresh_nodes(node)
-  refresh_entries(node.entries, node.absolute_path or node.cwd)
+  refresh_entries(node.entries, node.absolute_path or node.cwd, node)
   for _, entry in ipairs(node.entries) do
     if entry.entries and entry.open then
       refresh_nodes(entry)
@@ -159,7 +167,7 @@ function M.set_index_and_redraw(fname)
       if fname:match(entry.match_path..'/') ~= nil then
         if #entry.entries == 0 then
           reload = true
-          populate(entry.entries, entry.absolute_path)
+          populate(entry.entries, entry.absolute_path, entry)
         end
         if entry.open == false then
           reload = true
diff --git a/lua/nvim-tree/populate.lua b/lua/nvim-tree/populate.lua
index 59f2246293f..884c1cc86e1 100644
--- a/lua/nvim-tree/populate.lua
+++ b/lua/nvim-tree/populate.lua
@@ -34,6 +34,7 @@ local function dir_new(cwd, name)
     match_name = path_to_matching_str(name),
     match_path = path_to_matching_str(absolute_path),
     open = false,
+    group_next = nil,
     has_children = has_children,
     entries = {}
   }
@@ -78,6 +79,20 @@ local function link_new(cwd, name)
   }
 end
 
+local function should_group(cwd, dirs, files, links)
+  if #dirs == 1 and #files == 0 and #links == 0 then
+    return true
+  end
+
+  if #dirs == 0 and #files == 0 and #links == 1 then
+    local absolute_path = utils.path_join({ cwd, links[1] })
+    local link_to = luv.fs_realpath(absolute_path)
+    return (link_to ~= nil) and luv.fs_stat(link_to).type == 'directory'
+  end
+
+  return false
+end
+
 local function gen_ignore_check()
   local ignore_list = {}
   if vim.g.nvim_tree_ignore and #vim.g.nvim_tree_ignore > 0 then
@@ -100,7 +115,7 @@ end
 
 local should_ignore = gen_ignore_check()
 
-function M.refresh_entries(entries, cwd)
+function M.refresh_entries(entries, cwd, node_entry)
   local handle = luv.fs_scandir(cwd)
   if type(handle) == 'string' then
     api.nvim_err_writeln(handle)
@@ -120,10 +135,12 @@ function M.refresh_entries(entries, cwd)
   local links = {}
   local files = {}
   local new_entries = {}
+  local num_new_entries = 0
 
   while true do
     local name, t = luv.fs_scandir_next(handle)
     if not name then break end
+    num_new_entries = num_new_entries + 1
 
     if not should_ignore(name) then
       if t == 'directory' then
@@ -139,6 +156,21 @@ function M.refresh_entries(entries, cwd)
     end
   end
 
+  -- Handle grouped dirs
+  local next_node = node_entry.group_next
+  if next_node then
+    next_node.open = node_entry.open
+    if num_new_entries ~= 1 or not new_entries[next_node.name] then
+      -- dir is no longer only containing a group dir, or group dir has been removed
+      -- either way: sever the group link on current dir
+      node_entry.group_next = nil
+      named_entries[next_node.name] = next_node
+    else
+      M.refresh_entries(entries, next_node.absolute_path, next_node)
+      return
+    end
+  end
+
   local idx = 1
   for _, name in ipairs(cached_entries) do
     if not new_entries[name] then
@@ -173,12 +205,18 @@ function M.refresh_entries(entries, cwd)
           change_prev = false
         end
       end
-      if change_prev then prev = name end
+      if change_prev and not (next_node and next_node.name == name) then
+        prev = name
+      end
     end
   end
+
+  if next_node then
+    table.insert(entries, 1, next_node)
+  end
 end
 
-function M.populate(entries, cwd)
+function M.populate(entries, cwd, dir_entry)
   local handle = luv.fs_scandir(cwd)
   if type(handle) == 'string' then
     api.nvim_err_writeln(handle)
@@ -206,6 +244,20 @@ function M.populate(entries, cwd)
 
   -- Create Nodes --
 
+  -- Group empty dirs
+  if dir_entry and vim.g.nvim_tree_group_empty == 1 then
+    if should_group(cwd, dirs, files, links) then
+      local child
+      if dirs[1] then child = dir_new(cwd, dirs[1]) end
+      if links[1] then child = link_new(cwd, links[1]) end
+      if luv.fs_access(child.absolute_path, 'R') then
+          dir_entry.group_next = child
+          M.populate(entries, child.absolute_path, child)
+          return
+      end
+    end
+  end
+
   for _, dirname in ipairs(dirs) do
     local dir = dir_new(cwd, dirname)
     if luv.fs_access(dir.absolute_path, 'R') then
diff --git a/lua/nvim-tree/renderer.lua b/lua/nvim-tree/renderer.lua
index 552bad5ea02..7865c52f15a 100644
--- a/lua/nvim-tree/renderer.lua
+++ b/lua/nvim-tree/renderer.lua
@@ -252,17 +252,23 @@ local function update_draw_data(tree, depth, markers)
       local git_icon = get_git_icons(node, index, offset, #icon+1) or ""
       -- INFO: this is mandatory in order to keep gui attributes (bold/italics)
       local folder_hl = "NvimTreeFolderName"
+      local name = node.name
+      local next = node.group_next
+      while next do
+        name = name .. "/" .. next.name
+        next = next.group_next
+      end
       if not has_children then folder_hl = "NvimTreeEmptyFolderName" end
-      set_folder_hl(index, offset, #icon, #node.name+#git_icon, folder_hl)
+      set_folder_hl(index, offset, #icon, #name+#git_icon, folder_hl)
       if git_hl then
-        set_folder_hl(index, offset, #icon, #node.name+#git_icon, git_hl)
+        set_folder_hl(index, offset, #icon, #name+#git_icon, git_hl)
       end
       index = index + 1
       if node.open then
-        table.insert(lines, padding..icon..git_icon..node.name..(vim.g.nvim_tree_add_trailing == 1 and '/' or ''))
+        table.insert(lines, padding..icon..git_icon..name..(vim.g.nvim_tree_add_trailing == 1 and '/' or ''))
         update_draw_data(node, depth + 2, markers)
       else
-        table.insert(lines, padding..icon..git_icon..node.name..(vim.g.nvim_tree_add_trailing == 1 and '/' or ''))
+        table.insert(lines, padding..icon..git_icon..name..(vim.g.nvim_tree_add_trailing == 1 and '/' or ''))
       end
     elseif node.link_to then
       local icon = get_symlink_icon()

From 6a1da2b4d802ff5b55810e56a95e40e4cf4c092c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sindre=20T=2E=20Str=C3=B8m?= <sindrets@gmail.com>
Date: Thu, 25 Mar 2021 00:53:48 +0100
Subject: [PATCH 2/4] chore: Added documentation for g:nvim_tree_group_empty

---
 doc/nvim-tree-lua.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/doc/nvim-tree-lua.txt b/doc/nvim-tree-lua.txt
index a2068a20bbd..03151e534bc 100644
--- a/doc/nvim-tree-lua.txt
+++ b/doc/nvim-tree-lua.txt
@@ -203,6 +203,11 @@ functionnalities.
 Can be 0 or 1. When 1, appends a trailing slash to folder names.
 0 by default.
 
+|g:nvim_tree_group_empty|                         *g:nvim_tree_group_empty*
+
+Can be 0 or 1. When 1, folders that contain only one folder are grouped
+together. 0 by default.
+
 ==============================================================================
 INFORMATIONS				        *nvim-tree-info*
 

From 49648509bc381482c0e5eb874974729422028584 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sindre=20T=2E=20Str=C3=B8m?= <sindrets@gmail.com>
Date: Thu, 25 Mar 2021 01:18:07 +0100
Subject: [PATCH 3/4] chore: Added some code documentation.

---
 lua/nvim-tree/lib.lua      |  1 +
 lua/nvim-tree/populate.lua | 31 ++++++++++++++++++-------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/lua/nvim-tree/lib.lua b/lua/nvim-tree/lib.lua
index 03f435e1fad..9fafa7d4183 100644
--- a/lua/nvim-tree/lib.lua
+++ b/lua/nvim-tree/lib.lua
@@ -91,6 +91,7 @@ function M.get_node_at_cursor()
   return get_node_at_line(line)(M.Tree.entries)
 end
 
+-- If node is grouped, return the last node in the group. Otherwise, return the given node.
 function M.get_last_group_node(node)
   local next = node
   while next.group_next do
diff --git a/lua/nvim-tree/populate.lua b/lua/nvim-tree/populate.lua
index 884c1cc86e1..a2324ec0ae4 100644
--- a/lua/nvim-tree/populate.lua
+++ b/lua/nvim-tree/populate.lua
@@ -34,7 +34,7 @@ local function dir_new(cwd, name)
     match_name = path_to_matching_str(name),
     match_path = path_to_matching_str(absolute_path),
     open = false,
-    group_next = nil,
+    group_next = nil,   -- If node is grouped, this points to the next child dir/link node
     has_children = has_children,
     entries = {}
   }
@@ -79,6 +79,11 @@ local function link_new(cwd, name)
   }
 end
 
+-- Returns true if there is either exactly 1 dir, or exactly 1 symlink dir. Otherwise, false.
+-- @param cwd Absolute path to the parent directory
+-- @param dirs List of dir names
+-- @param files List of file names
+-- @param links List of symlink names
 local function should_group(cwd, dirs, files, links)
   if #dirs == 1 and #files == 0 and #links == 0 then
     return true
@@ -115,7 +120,7 @@ end
 
 local should_ignore = gen_ignore_check()
 
-function M.refresh_entries(entries, cwd, node_entry)
+function M.refresh_entries(entries, cwd, parent_node)
   local handle = luv.fs_scandir(cwd)
   if type(handle) == 'string' then
     api.nvim_err_writeln(handle)
@@ -157,13 +162,13 @@ function M.refresh_entries(entries, cwd, node_entry)
   end
 
   -- Handle grouped dirs
-  local next_node = node_entry.group_next
+  local next_node = parent_node.group_next
   if next_node then
-    next_node.open = node_entry.open
+    next_node.open = parent_node.open
     if num_new_entries ~= 1 or not new_entries[next_node.name] then
       -- dir is no longer only containing a group dir, or group dir has been removed
       -- either way: sever the group link on current dir
-      node_entry.group_next = nil
+      parent_node.group_next = nil
       named_entries[next_node.name] = next_node
     else
       M.refresh_entries(entries, next_node.absolute_path, next_node)
@@ -216,7 +221,7 @@ function M.refresh_entries(entries, cwd, node_entry)
   end
 end
 
-function M.populate(entries, cwd, dir_entry)
+function M.populate(entries, cwd, parent_node)
   local handle = luv.fs_scandir(cwd)
   if type(handle) == 'string' then
     api.nvim_err_writeln(handle)
@@ -245,14 +250,14 @@ function M.populate(entries, cwd, dir_entry)
   -- Create Nodes --
 
   -- Group empty dirs
-  if dir_entry and vim.g.nvim_tree_group_empty == 1 then
+  if parent_node and vim.g.nvim_tree_group_empty == 1 then
     if should_group(cwd, dirs, files, links) then
-      local child
-      if dirs[1] then child = dir_new(cwd, dirs[1]) end
-      if links[1] then child = link_new(cwd, links[1]) end
-      if luv.fs_access(child.absolute_path, 'R') then
-          dir_entry.group_next = child
-          M.populate(entries, child.absolute_path, child)
+      local child_node
+      if dirs[1] then child_node = dir_new(cwd, dirs[1]) end
+      if links[1] then child_node = link_new(cwd, links[1]) end
+      if luv.fs_access(child_node.absolute_path, 'R') then
+          parent_node.group_next = child_node
+          M.populate(entries, child_node.absolute_path, child_node)
           return
       end
     end

From a5bb8d87e44b6ca7e4b6db2980232dac12f2e258 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sindre=20T=2E=20Str=C3=B8m?= <sindrets@gmail.com>
Date: Thu, 25 Mar 2021 11:11:01 +0100
Subject: [PATCH 4/4] chore: Updated README to reflect new option

---
 README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/README.md b/README.md
index 653a6bf21e9..f9586b8ce67 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,7 @@ let g:nvim_tree_width_allow_resize  = 1 "0 by default, will not resize the tree
 let g:nvim_tree_disable_netrw = 0 "1 by default, disables netrw
 let g:nvim_tree_hijack_netrw = 0 "1 by default, prevents netrw from automatically opening when opening directories (but lets you keep its other utilities)
 let g:nvim_tree_add_trailing = 1 "0 by default, append a trailing slash to folder names
+let g:nvim_tree_group_empty = 1 " 0 by default, compact folders that only contain a single folder into one node in the file tree
 let g:nvim_tree_show_icons = {
     \ 'git': 1,
     \ 'folders': 0,