Merge duplicate notifications

lua/notify/config/init.lua

@@ -30,6 +30,7 @@ local default_config = {
   minimum_width = 50,
   fps = 30,
   top_down = true,
+  merge_duplicates = true,
   time_formats = {
     notification_history = "%FT%T",
     notification = "%T",
@@ -58,6 +59,7 @@ local default_config = {
 ---@field minimum_width integer Minimum width for notification windows
 ---@field fps integer Frames per second for animation stages, higher value means smoother animations but more CPU usage
 ---@field top_down boolean whether or not to position the notifications at the top or not
+---@field merge_duplicates boolean|integer whether to replace visible notification if new one is the same, can be an integer for min duplicate count
 
 local opacity_warned = false
 
@@ -156,6 +158,10 @@ function Config.setup(custom_config)
     return user_config.top_down
   end
 
+  function config.merge_duplicates()
+    return user_config.merge_duplicates
+  end
+
   function config.on_close()
     return user_config.on_close
   end

lua/notify/instance.lua

@@ -6,6 +6,32 @@ local NotificationService = require("notify.service")
 local NotificationBuf = require("notify.service.buffer")
 local stage_util = require("notify.stages.util")
 
+local notif_cmp_keys = {
+  "level",
+  "message",
+  "title",
+  "icon",
+}
+
+---@param n1 notify.Notification
+---@param n2 notify.Notification
+---@return boolean
+local function notifications_equal(n1, n2)
+  for _, key in ipairs(notif_cmp_keys) do
+    local v1 = n1[key]
+    local v2 = n2[key]
+    -- NOTE: Notification:new adds time string which causes not-equality, so compare only left title (1st element)
+    if key == "title" then
+      v1 = v1[1]
+      v2 = v2[1]
+    end
+    if not vim.deep_equal(v1, v2) then
+      return false
+    end
+  end
+  return true
+end
+
 ---@param user_config notify.Config
 ---@param inherit? boolean Inherit the global configuration, default true
 ---@param global_config notify.Config
@@ -38,8 +64,19 @@ return function(user_config, inherit, global_config)
     return require("notify.render")[render]
   end
 
+  ---@param notif notify.Notification
+  ---@return notify.Notification?
+  local function find_duplicate(notif)
+    for _, buf in pairs(animator.notif_bufs) do
+      if notifications_equal(buf._notif, notif) then
+        return buf._notif
+      end
+    end
+  end
+
   function instance.notify(message, level, opts)
     opts = opts or {}
+
     if opts.replace then
       if type(opts.replace) == "table" then
         opts.replace = opts.replace.id
@@ -66,11 +103,27 @@ return function(user_config, inherit, global_config)
         opts[key] = opts[key] or existing[key]
       end
     end
+
     opts.render = get_render(opts.render or instance_config.render())
     local id = #notifications + 1
     local notification = Notification(id, message, level, opts, instance_config)
     table.insert(notifications, notification)
     local level_num = vim.log.levels[notification.level]
+
+    if not opts.replace and instance_config.merge_duplicates() then
+      local dup = find_duplicate(notification)
+      if dup then
+        dup.duplicates = dup.duplicates or { dup.id }
+        table.insert(dup.duplicates, notification.id)
+        notification.duplicates = dup.duplicates
+
+        local min_dups = instance_config.merge_duplicates()
+        if min_dups == true or #notification.duplicates >= min_dups + 1 then
+          opts.replace = dup.id
+        end
+      end
+    end
+
     if opts.replace then
       service:replace(opts.replace, notification)
     elseif not level_num or level_num >= instance_config.level() then

lua/notify/render/compact.lua

@@ -5,15 +5,22 @@ return function(bufnr, notif, highlights)
   local icon = notif.icon
   local title = notif.title[1]
 
+  if type(title) == "string" and notif.duplicates then
+    title = string.format('%s x%d', title, #notif.duplicates)
+  end
+
   local prefix
   if type(title) == "string" and #title > 0 then
     prefix = string.format("%s | %s:", icon, title)
   else
     prefix = string.format("%s |", icon)
   end
-  notif.message[1] = string.format("%s %s", prefix, notif.message[1])
+  local message = {
+    string.format("%s %s", prefix, notif.message[1]),
+    unpack(notif.message, 2)
+  }
 
-  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, notif.message)
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, message)
 
   local icon_length = vim.str_utfindex(icon)
   local prefix_length = vim.str_utfindex(prefix)
@@ -30,7 +37,7 @@ return function(bufnr, notif, highlights)
   })
   vim.api.nvim_buf_set_extmark(bufnr, namespace, 0, prefix_length + 1, {
     hl_group = highlights.body,
-    end_line = #notif.message,
+    end_line = #message,
     priority = 50,
   })
 end

lua/notify/render/default.lua

@@ -8,6 +8,9 @@ return function(bufnr, notif, highlights, config)
   end, notif.message))))
   local right_title = notif.title[2]
   local left_title = notif.title[1]
+  if notif.duplicates then
+    left_title = string.format('%s (x%d)', left_title, #notif.duplicates)
+  end
   local title_accum = vim.str_utfindex(left_icon)
     + vim.str_utfindex(right_title)
     + vim.str_utfindex(left_title)

lua/notify/render/minimal.lua

@@ -2,13 +2,21 @@ local api = vim.api
 local base = require("notify.render.base")
 
 return function(bufnr, notif, highlights)
+  local message = notif.message
+  if notif.duplicates then
+    message = {
+      string.format("x%d %s", #notif.duplicates, notif.message[1]),
+      unpack(notif.message, 2)
+    }
+  end
+
   local namespace = base.namespace()
-  api.nvim_buf_set_lines(bufnr, 0, -1, false, notif.message)
+  api.nvim_buf_set_lines(bufnr, 0, -1, false, message)
 
   api.nvim_buf_set_extmark(bufnr, namespace, 0, 0, {
     hl_group = highlights.icon,
-    end_line = #notif.message - 1,
-    end_col = #notif.message[#notif.message],
+    end_line = #message - 1,
+    end_col = #message[#message],
     priority = 50,
   })
 end

lua/notify/render/simple.lua

@@ -6,6 +6,9 @@ return function(bufnr, notif, highlights, config)
     return vim.fn.strchars(line)
   end, notif.message))))
   local title = notif.title[1]
+  if notif.duplicates then
+    title = string.format('%s (x%d)', title, #notif.duplicates)
+  end
   local title_accum = vim.str_utfindex(title)
 
   local title_buffer = string.rep(

lua/notify/render/wrapped-compact.lua

@@ -59,10 +59,16 @@ return function(bufnr, notif, highlights, config)
   if has_valid_manual_title then
     -- has title = icon + title as header row
     prefix = string.format(" %s %s", icon, title)
+    if notif.duplicates then
+      prefix = string.format('%s x%d', prefix, #notif.duplicates)
+    end
     table.insert(message, 1, prefix)
   else
     -- no title = prefix the icon
     prefix = string.format(" %s", icon)
+    if notif.duplicates then
+      prefix = string.format('%s x%d', prefix, #notif.duplicates)
+    end
     message[1] = string.format("%s %s", prefix, message[1])
   end
 

lua/notify/service/notification.lua

@@ -13,6 +13,7 @@
 ---@field on_open fun(win: number, record: notify.Record) | nil
 ---@field on_close fun(win: number, record: notify.Record) | nil
 ---@field render fun(buf: integer, notification: notify.Notification, highlights: table<string, string>)
+---@field duplicates? integer[] shared list of duplicate notifications by id
 local Notification = {}
 
 local level_maps = vim.tbl_extend("keep", {}, vim.log.levels)
@@ -52,6 +53,7 @@ function Notification:new(id, message, level, opts, config)
     animate = opts.animate ~= false,
     render = opts.render,
     hide_from_history = opts.hide_from_history,
+    duplicates = opts.duplicates,
   }
   self.__index = self
   setmetatable(notif, self)

tests/manual/merge_duplicates.lua

@@ -0,0 +1,75 @@
+local function coroutine_resume()
+    local co = assert(coroutine.running())
+    return function(...)
+        local ret = { coroutine.resume(co, ...) }
+        -- Re-raise errors with correct traceback
+        local ok, err = unpack(ret)
+        if not ok then
+            error(debug.traceback(co, err))
+        end
+        return unpack(ret, 2)
+    end
+end
+
+local function coroutine_sleep()
+    local resume = coroutine_resume()
+    return function(ms)
+        vim.defer_fn(resume, ms)
+        coroutine.yield()
+    end
+end
+
+local function run()
+    local sleep = coroutine_sleep()
+
+    local countdown = function(seconds)
+        local id
+        for i = 1, seconds do
+            -- local msg = string.format('Will show once again in %d seconds', seconds - i + 1)
+            local msg = string.format('Will show once again in %d seconds', seconds - i + 1)
+            id = vim.notify(msg, vim.log.levels.WARN, { replace = id }).id
+            sleep(1000)
+        end
+    end
+
+    local texts = {
+        'AAA This is first text',
+        'BBBBBB Second text of duplicate notifications',
+        -- 'CCCCCCCCC Third text',
+    }
+
+    local show_all = function(level)
+        for _, text in ipairs(texts) do
+            vim.notify(text, level)
+            sleep(50)
+        end
+    end
+
+    show_all()
+
+    sleep(1000)
+    show_all()
+
+    sleep(1000)
+    show_all()
+
+    sleep(1000)
+    show_all(vim.log.levels.WARN)
+    sleep(1000)
+    show_all(vim.log.levels.WARN)
+
+    sleep(1000)
+    show_all()
+
+    -- wait until the previous notifications disappear
+    countdown(10)
+    show_all()
+
+    sleep(2000)
+    for _ = 1, 41 do
+        sleep(50)
+        show_all()
+    end
+end
+
+coroutine.wrap(run)()