feat: GH-40 Add pattern to trigger_events (#42)

README.md

@@ -119,9 +119,26 @@ EOF
 }
 ```
 
+### Trigger Events
+
+The `trigger_events` field of the configuration allows the user to customize at which events **auto-save** saves.
+While the default are very sane and should be enough for most usecases, finetuning for extended possibilities is supported.
+
+It is also possible to pass a pattern to a trigger event, if you only want to execute the event on special file patterns:
+
+``` lua
+{
+  trigger_events = {
+    immediate_save = {
+      { "BufLeave", pattern = {"*.c", "*.h"} }
+    }
+  }
+}
+```
+
 ### Condition
 
-The condition field of the configuration allows the user to exclude **auto-save** from saving specific buffers.
+The `condition` field of the configuration allows the user to exclude **auto-save** from saving specific buffers.
 
 Here is an example using a helper function from `auto-save.utils.data` that disables auto-save for specified file types:
 

lua/auto-save/config.lua

@@ -12,11 +12,11 @@ Config = {
       cleaning_interval = 1250, -- (milliseconds) automatically clean MsgArea after displaying `message`. See :h MsgArea
     },
     trigger_events = { -- See :h events
-      --- @type nil|string[]
+      --- @type TriggerEvent[]?
       immediate_save = { "BufLeave", "FocusLost" }, -- vim events that trigger an immediate save
-      --- @type nil|string[]
+      --- @type TriggerEvent[]?
       defer_save = { "InsertLeave", "TextChanged" }, -- vim events that trigger a deferred save (saves after `debounce_delay`)
-      --- @type nil|string[]
+      --- @type TriggerEvent[]?
       cancel_defered_save = { "InsertEnter" }, -- vim events that cancel a pending deferred save
     },
     -- function that takes the buffer handle and determines whether to save the current buffer or not

lua/auto-save/init.lua

@@ -117,40 +117,33 @@ function M.on()
   local augroup = autocmds.create_augroup({ clear = true })
 
   local events = cnf.opts.trigger_events
-
-  if events.immediate_save ~= nil and #events.immediate_save > 0 then
-    api.nvim_create_autocmd(events.immediate_save, {
-      callback = function(opts)
-        if should_be_saved(opts.buf) then
-          immediate_save(opts.buf)
-        end
-      end,
-      group = augroup,
-      desc = "Immediately save a buffer",
-    })
-  end
-  if events.defer_save ~= nil and #events.defer_save > 0 then
-    api.nvim_create_autocmd(events.defer_save, {
-      callback = function(opts)
-        if should_be_saved(opts.buf) then
-          defer_save(opts.buf)
-        end
-      end,
-      group = augroup,
-      desc = "Save a buffer after the `debounce_delay`",
-    })
-  end
-  if events.cancel_defered_save ~= nil and #events.cancel_defered_save > 0 then
-    api.nvim_create_autocmd(events.cancel_defered_save, {
-      callback = function(opts)
-        if should_be_saved(opts.buf) then
-          cancel_timer(opts.buf)
-        end
-      end,
-      group = augroup,
-      desc = "Cancel a pending save timer for a buffer",
-    })
-  end
+  autocmds.create_autocmd_for_trigger_events(events.immediate_save, {
+    callback = function(opts)
+      if should_be_saved(opts.buf) then
+        immediate_save(opts.buf)
+      end
+    end,
+    group = augroup,
+    desc = "Immediately save a buffer",
+  })
+  autocmds.create_autocmd_for_trigger_events(events.defer_save, {
+    callback = function(opts)
+      if should_be_saved(opts.buf) then
+        defer_save(opts.buf)
+      end
+    end,
+    group = augroup,
+    desc = "Save a buffer after the `debounce_delay`",
+  })
+  autocmds.create_autocmd_for_trigger_events(events.cancel_defered_save, {
+    callback = function(opts)
+      if should_be_saved(opts.buf) then
+        cancel_timer(opts.buf)
+      end
+    end,
+    group = augroup,
+    desc = "Cancel a pending save timer for a buffer",
+  })
 
   local function setup_dimming()
     if cnf.opts.execution_message.enabled then

lua/auto-save/types.lua

@@ -0,0 +1,4 @@
+--- @meta
+
+--- @alias VerboseTriggerEvent { [1]: string, pattern?: string }
+--- @alias TriggerEvent string | VerboseTriggerEvent

lua/auto-save/utils/autocommands.lua

@@ -3,6 +3,15 @@ local M = {}
 local api = vim.api
 local augroup_name = "AutoSave"
 
+--- @param event TriggerEvent
+--- @return VerboseTriggerEvent
+local function parse_trigger_event(event)
+  if type(event) == "string" then
+    return { event }
+  end
+  return event
+end
+
 --- @param opts? table
 --- @return number
 M.create_augroup = function(opts)
@@ -16,4 +25,15 @@ M.exec_autocmd = function(pattern, saved_buffer)
   api.nvim_exec_autocmds("User", { pattern = pattern, data = { saved_buffer = saved_buffer } })
 end
 
+--- @param trigger_events TriggerEvent[]?
+M.create_autocmd_for_trigger_events = function(trigger_events, autocmd_opts)
+  if trigger_events ~= nil then
+    for _, event in pairs(trigger_events) do
+      local parsed_event = parse_trigger_event(event)
+      local autocmd_opts_with_pattern = vim.tbl_extend("force", autocmd_opts, { pattern = parsed_event.pattern })
+      api.nvim_create_autocmd(parsed_event[1], autocmd_opts_with_pattern)
+    end
+  end
+end
+
 return M