feat: Mixin Sorter (#1565) Self Solved

doc/nvim-tree-lua.txt

@@ -414,10 +414,22 @@ Opens the tree automatically when switching tabpage or opening a new tabpage
 if the tree was previously open.
   Type: `boolean`, Default: `false`
 
+
 *nvim-tree.sort_by*
 Changes how files within the same directory are sorted.
-Can be one of 'name', 'case_sensitive', 'modification_time' or 'extension'.
-  Type: `string`, Default: `"name"`
+Can be one of 'name', 'case_sensitive', 'modification_time' or 'extension',
+'function'.
+  Type: `string | function(table)`, Default: `"name"`
+>
+  sort_by = function(tbl)
+
+    local user_order = {};
+    for i = 1, #tbl do
+      table.insert(user_order, tbl.absolute_path)
+    end
+
+    return user_oder
+  end
 
 *nvim-tree.hijack_unnamed_buffer_when_opening*
 Opens in place of the unnamed buffer if it's empty.

lua/nvim-tree.lua

@@ -640,6 +640,7 @@ local FIELD_OVERRIDE_TYPECHECK = {
   height = { string = true, ["function"] = true, number = true },
   remove_keymaps = { boolean = true, table = true },
   on_attach = { ["function"] = true, string = true },
+  sort_by = { ["function"] = true, string = true },
 }
 
 local function validate_options(conf)

lua/nvim-tree/explorer/sorters.lua

@@ -66,13 +66,39 @@ end
 ---@param t any[]
 ---@param comparator function|nil
 function M.merge_sort(t, comparator)
-  if not comparator then
-    comparator = function(left, right)
-      return left < right
+  if type(M.sort_by) == "function" then
+    local t_user = {}
+    for _, n in ipairs(t) do
+      table.insert(t_user, {
+        absolute_path = n.absolute_path,
+        executable = n.executable,
+        extension = n.extension,
+        link_to = n.link_to,
+        name = n.name,
+        type = n.type,
+      })
     end
-  end
 
-  split_merge(t, 1, #t, comparator)
+    local user_order = M.sort_by(t_user)
+
+    for i = 1, #user_order, 1 do
+      for j = 1, #t, 1 do
+        if t[j].absolute_path == user_order[i] then
+          local tmp = t[i]
+          t[i] = t[j]
+          t[j] = tmp
+          break
+        end
+      end
+    end -- reorder the list according to the user order
+  else
+    if not comparator then
+      comparator = function(left, right)
+        return left < right
+      end
+    end
+    split_merge(t, 1, #t, comparator)
+  end
 end
 
 local function node_comparator_name_ignorecase_or_not(a, b, ignorecase)
@@ -150,7 +176,9 @@ end
 
 function M.setup(opts)
   M.sort_by = opts.sort_by
-  if M.sort_by == "modification_time" then
+  if M.sort_by and type(M.sort_by) ~= "function" then
+    M.node_comparator = M.sort_by
+  elseif M.sort_by == "modification_time" then
     M.node_comparator = M.node_comparator_modification_time
   elseif M.sort_by == "case_sensitive" then
     M.node_comparator = M.node_comparator_name_case_sensisive