From ebf15fc198d6c82f64c17e0b752a30fd4c3cdbc7 Mon Sep 17 00:00:00 2001
From: Folke Lemaitre <folke.lemaitre@gmail.com>
Date: Fri, 2 Dec 2022 17:01:05 +0100
Subject: [PATCH] feat: for `event=`, fire any new autocmds created by loading
 the plugins for the event

---
 lua/lazy/core/handler.lua | 77 +++++++++++++++++++++++++++++++++------
 1 file changed, 66 insertions(+), 11 deletions(-)

diff --git a/lua/lazy/core/handler.lua b/lua/lazy/core/handler.lua
index eb040fd..b862d02 100644
--- a/lua/lazy/core/handler.lua
+++ b/lua/lazy/core/handler.lua
@@ -29,23 +29,79 @@ function M.setup()
   end
 end
 
+---@param events string|string[]
+---@param pattern? string
+function M.get_augroups(events, pattern)
+  -- Check for all autocmd groups listening for the events
+  ---@type table<string,true>
+  local groups = {}
+  for _, autocmd in ipairs(vim.api.nvim_get_autocmds({ event = events, pattern = pattern })) do
+    if autocmd.group then
+      groups[autocmd.group] = true
+    end
+  end
+  return groups
+end
+
+---@param groups table<string,true>
+---@param events string|string[]
+---@param pattern? string
+function M.trigger(groups, events, pattern)
+  events = type(events) == "string" and { events } or events
+  ---@cast events string[]
+  for _, event in ipairs(events) do
+    for _, autocmd in ipairs(vim.api.nvim_get_autocmds({ event = event, pattern = pattern })) do
+      if autocmd.event == event and autocmd.group and not groups[autocmd.group] then
+        if Config.options.debug then
+          local lines = {
+            "# Firing Events",
+            "  - **event:** " .. autocmd.event,
+            "  - **group:** `" .. autocmd.group_name .. "`",
+          }
+          if pattern then
+            table.insert(lines, 2, "- **pattern:** " .. pattern)
+          end
+          Util.info(lines)
+        end
+        vim.api.nvim_exec_autocmds(autocmd.event, { group = autocmd.group, modeline = false })
+      end
+    end
+  end
+end
+
 ---@type table<string, LazyHandler>
 M.handlers = {}
 function M.handlers.event(grouped)
   local group = vim.api.nvim_create_augroup("lazy_handler_event", { clear = true })
-  for event, plugins in pairs(grouped) do
-    ---@cast event string
-    if event == "VimEnter" and vim.v.vim_did_enter == 1 then
-      Loader.load(plugins, { event = event })
+  for event_spec, plugins in pairs(grouped) do
+    if event_spec == "VeryLazy" then
+      event_spec = "User VeryLazy"
+    end
+    if event_spec == "VimEnter" and vim.v.vim_did_enter == 1 then
+      Loader.load(plugins, { event = event_spec })
     else
-      local _event, pattern = event:match("^(%w+)%s+(.*)$")
-      vim.api.nvim_create_autocmd(_event or event, {
+      local event, pattern = event_spec:match("^(%w+)%s+(.*)$")
+      event = event or event_spec
+      vim.api.nvim_create_autocmd(event, {
         group = group,
         once = true,
         pattern = pattern,
         callback = function()
-          Util.track({ event = event })
-          Loader.load(plugins, { event = event })
+          Util.track({ event = event_spec })
+          local events = { event }
+          if event == "BufRead" then
+            events = { "BufReadPre", "BufRead" }
+          elseif event == "BufReadPost" then
+            events = { "BufReadPre", "BufRead", "BufReadPost" }
+          end
+
+          local groups = M.get_augroups(events, pattern)
+
+          -- load the plugins
+          Loader.load(plugins, { event = event_spec })
+
+          -- check if any plugin created an event handler for this event and fire the group
+          M.trigger(groups, events, pattern)
           Util.track()
         end,
       })
@@ -55,7 +111,6 @@ end
 
 function M.handlers.keys(grouped)
   for keys, plugins in pairs(grouped) do
-    ---@cast keys string
     vim.keymap.set("n", keys, function()
       vim.keymap.del("n", keys)
       Util.track({ keys = keys })
@@ -69,14 +124,15 @@ end
 function M.handlers.ft(grouped)
   local group = vim.api.nvim_create_augroup("lazy_handler_ft", { clear = true })
   for ft, plugins in pairs(grouped) do
-    ---@cast ft string
     vim.api.nvim_create_autocmd("FileType", {
       once = true,
       pattern = ft,
       group = group,
       callback = function()
         Util.track({ ft = ft })
+        local groups = M.get_augroups("FileType", ft)
         Loader.load(plugins, { ft = ft })
+        M.trigger(groups, "FileType", ft)
         Util.track()
       end,
     })
@@ -85,7 +141,6 @@ end
 
 function M.handlers.cmd(grouped)
   for cmd, plugins in pairs(grouped) do
-    ---@cast cmd string
     local function _load()
       vim.api.nvim_del_user_command(cmd)
       Util.track({ cmd = cmd })