fix(statistics cookie): count only TODO headlines

lua/orgmode/files/headline.lua

@@ -946,14 +946,19 @@ function Headline:update_todo_cookie()
     return self
   end
 
-  -- Count done children headlines
+  -- Count done children headlines and total children with TODO keywords
   local children = self:get_child_headlines()
+  local headlines_with_todo = vim.tbl_filter(function(h)
+    local todo, _, _ = h:get_todo()
+    return todo ~= nil
+  end, children)
+
   local dones = vim.tbl_filter(function(h)
     return h:is_done()
-  end, children)
+  end, headlines_with_todo)
 
   -- Set the cookie
-  return self:_set_cookie(cookie, #dones, #children)
+  return self:_set_cookie(cookie, #dones, #headlines_with_todo)
 end
 
 function Headline:update_parent_cookie()

tests/plenary/ui/mappings/todo_spec.lua

@@ -430,4 +430,25 @@ describe('Todo mappings', function()
       '** TODO item',
     }, vim.api.nvim_buf_get_lines(0, 0, 6, false))
   end)
+  it('should update headline cookies when children todo state changes', function()
+    helpers.create_file({
+      '* Test orgmode [/]',
+      '** TODO item',
+      '** TODO item',
+      '** TODO item',
+      '** Non-todo item',
+    })
+    vim.fn.cursor(4, 1)
+    local now = Date.now()
+    -- Changing to DONE and adding closed date
+    vim.cmd([[norm citd]])
+    assert.are.same({
+      '* Test orgmode [1/3]',
+      '** TODO item',
+      '** TODO item',
+      '** DONE item',
+      '   CLOSED: [' .. now:to_string() .. ']',
+      '** Non-todo item',
+    }, vim.api.nvim_buf_get_lines(0, 0, 6, false))
+  end)
 end)