feat: expose number pending

Closes #120

doc/nvim-notify.txt

@@ -91,7 +91,7 @@ notify.setup({user_config})                                   *notify.setup()*
       }
 
     Parameters: ~
-        {user_config} (notify.Config)
+        {user_config} (notify.Config|nil)
 
     See: ~
         |notify-render()|
@@ -164,6 +164,14 @@ notify.dismiss({opts})                                      *notify.dismiss()*
                              were dismissed.
 
 
+notify.pending()                                            *notify.pending()*
+    Number of notifications currently waiting to be displayed
+
+
+    Return: ~
+        table<integer, integer>
+
+
 notify.instance({user_config}, {inherit})                  *notify.instance()*
     Configure an instance of nvim-notify. You can use this to manage a separate
     instance of nvim-notify with completely different configuration. The

lua/notify/init.lua

@@ -23,7 +23,7 @@ local global_instance, global_config
 ---    See: ~
 ---        |notify.Config|
 ---</pre>
----@param user_config notify.Config
+---@param user_config notify.Config | nil
 ---@eval { ['description'] = require('notify.config')._format_default() }
 ---@see notify-render
 function notify.setup(user_config)
@@ -126,6 +126,15 @@ function notify.dismiss(opts)
   return global_instance.dismiss(opts)
 end
 
+---Number of notifications currently waiting to be displayed
+---@return table<integer, integer>
+function notify.pending()
+  if not global_instance then
+    notify.setup()
+  end
+  return global_instance.pending()
+end
+
 function notify._print_history()
   if not global_instance then
     notify.setup()
@@ -254,6 +263,10 @@ function notify.instance(user_config, inherit)
     end
   end
 
+  function instance.pending()
+    return service and service:pending() or {}
+  end
+
   setmetatable(instance, {
     __call = function(_, m, l, o)
       if vim.in_fast_event() then

lua/notify/service/init.lua

@@ -106,6 +106,10 @@ function NotificationService:dismiss(opts)
   end
 end
 
+function NotificationService:pending()
+  return self._pending:length()
+end
+
 ---@return NotificationService
 return function(config, animator)
   return NotificationService:new(config, animator)