feat: Mixin Sorter (#1565) Self Solved

doc/nvim-tree-lua.txt

@@ -416,7 +416,8 @@ if the tree was previously open.
 
 *nvim-tree.sort_by*
 Changes how files within the same directory are sorted.
-Can be one of 'name', 'case_sensitive', 'modification_time' or 'extension'.
+Can be one of 'name', 'case_sensitive', 'modification_time' or 'extension' or
+'mixin'.
   Type: `string`, Default: `"name"`
 
 *nvim-tree.hijack_unnamed_buffer_when_opening*

lua/nvim-tree/explorer/sorters.lua

@@ -73,6 +73,9 @@ function M.merge_sort(t, comparator)
   end
 
   split_merge(t, 1, #t, comparator)
+  if M.sort_by == "mixin" then
+    M.node_inserter_mixin(t)
+  end
 end
 
 local function node_comparator_name_ignorecase_or_not(a, b, ignorecase)
@@ -148,6 +151,26 @@ function M.node_comparator_extension(a, b)
   return a.extension:lower() <= b.extension:lower()
 end
 
+function M.node_inserter_mixin(t)
+  local i = 1
+
+  while i <= #t do
+    if t[i] and t[i].nodes then
+      local j = i + 1
+      while j <= #t do
+        if t[j] and not t[j].nodes and t[i].name:lower() == t[j].name:lower():match "(.+)%..+$" then
+          local change_target = t[j]
+          table.remove(t, j)
+          table.insert(t, i, change_target)
+          break
+        end
+        j = j + 1
+      end
+    end
+    i = i + 1
+  end
+end
+
 function M.setup(opts)
   M.sort_by = opts.sort_by
   if M.sort_by == "modification_time" then