feat(diag): add diagnostics_update_on_event option

doc/bufferline.txt

@@ -101,6 +101,7 @@ The available configuration are:
             tab_size = 18,
             diagnostics = false | "nvim_lsp" | "coc",
             diagnostics_update_in_insert = false,
+            diagnostics_update_on_event = false, -- use nvim's diagnostic handler
             -- The diagnostics indicator can be set to nil to keep the buffer name highlight but delete the highlighting
             diagnostics_indicator = function(count, level, diagnostics_dict, context)
                 return "("..count..")"

lua/bufferline.lua

@@ -181,6 +181,15 @@ local function setup_commands()
   })
 end
 
+local function setup_diagnostic_handler(preferences)
+  if preferences.options.diagnostics == "nvim_lsp" and preferences.options.diagnostics_update_on_event then
+    vim.diagnostic.handlers["bufferline"] = {
+      show = function() ui.refresh() end,
+      hide = function() ui.refresh() end,
+    }
+  end
+end
+
 ---@param conf bufferline.UserConfig?
 function M.setup(conf)
   conf = conf or {}
@@ -192,6 +201,7 @@ function M.setup(conf)
   hover.setup(preferences)
   setup_commands()
   setup_autocommands(preferences)
+  setup_diagnostic_handler(preferences)
   vim.o.tabline = "%!v:lua.nvim_bufferline()"
   toggle_bufferline()
 end

lua/bufferline/config.lua

@@ -657,6 +657,7 @@ local function get_defaults()
     diagnostics = false,
     diagnostics_indicator = nil,
     diagnostics_update_in_insert = true,
+    diagnostics_update_on_event = false,
     offsets = {},
     groups = { items = {}, options = { toggle_hidden_on_enter = true } },
     hover = { enabled = false, reveal = {}, delay = 200 },

lua/bufferline/types.lua

@@ -62,6 +62,7 @@
 ---@field public diagnostics? boolean | 'nvim_lsp' | 'coc'
 ---@field public diagnostics_indicator? bufferline.DiagnosticIndicator
 ---@field public diagnostics_update_in_insert? boolean
+---@field public diagnostics_update_on_event? boolean
 ---@field public offsets? table[]
 ---@field public groups? bufferline.GroupOpts
 ---@field public themable? boolean