From df435cee434eb1e71fa797f6c51f7a0d567892a6 Mon Sep 17 00:00:00 2001
From: olimorris <olimorris@users.noreply.github.com>
Date: Fri, 7 Oct 2022 12:46:58 +0100
Subject: [PATCH] feat: :sparkles: #31 should_autosave callback

---
 README.md                | 16 ++++++++++++++++
 lua/persisted/config.lua |  1 +
 lua/persisted/init.lua   |  9 ++++++++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 6e0f316..2976ff8 100644
--- a/README.md
+++ b/README.md
@@ -130,6 +130,7 @@ require("persisted").setup({
   use_git_branch = false, -- create session files based on the branch of the git enabled repository
   branch_separator = "_", -- string used to separate session directory name from branch name
   autosave = true, -- automatically save session files when exiting Neovim
+  should_autosave = nil, -- function to determine if a session should be autosaved
   autoload = false, -- automatically load the session for the cwd on Neovim startup
   on_autoload_no_session = nil, -- function to run when `autoload = true` but there is no session to load
   allowed_dirs = nil, -- table of dirs that the plugin will auto-save and auto-load from
@@ -197,6 +198,21 @@ require("persisted").setup({
 
 Autosaving can be further controlled for certain directories by specifying `allowed_dirs` and `ignored_dirs`.
 
+There may be occasions when you do not wish to autosave; perhaps when a dashboard or terminal are open. To control this,
+a callback function, `should_autosave`, may be specified. This function should return a boolean value.
+
+```lua
+require("persisted").setup({
+  should_autosave = function()
+    -- do not autosave if the alpha dashboard is the current filetype
+    if vim.bo.filetype == "alpha" then
+      return false
+    end
+    return true
+  end,
+})
+```
+
 ### Autoloading
 
 The plugin can be enabled to automatically load sessions when Neovim is started. Whilst off by default, this can be turned on by:
diff --git a/lua/persisted/config.lua b/lua/persisted/config.lua
index 4d73b71..c751ed7 100644
--- a/lua/persisted/config.lua
+++ b/lua/persisted/config.lua
@@ -8,6 +8,7 @@ local defaults = {
   use_git_branch = false, -- create session files based on the branch of the git enabled repository
   branch_separator = "_", -- string used to separate session directory name from branch name
   autosave = true, -- automatically save session files when exiting Neovim
+  should_autosave = nil, -- function to determine if a session should be autosaved
   autoload = false, -- automatically load the session for the cwd on Neovim startup
   allowed_dirs = nil, -- table of dirs that the plugin will auto-save and auto-load from
   ignored_dirs = nil, -- table of dirs that are ignored for auto-saving and auto-loading
diff --git a/lua/persisted/init.lua b/lua/persisted/init.lua
index 45eb0df..501c0ef 100644
--- a/lua/persisted/init.lua
+++ b/lua/persisted/init.lua
@@ -105,7 +105,7 @@ function M.load(opt)
   if session then
     if vim.fn.filereadable(session) ~= 0 then
       utils.load_session(session, config.options.before_source, config.options.after_source, config.options.silent)
-    elseif type(config.options.on_autoload_no_session) == 'function' then
+    elseif type(config.options.on_autoload_no_session) == "function" then
       config.options.on_autoload_no_session()
     end
   end
@@ -149,6 +149,13 @@ function M.save()
     config.options.before_save()
   end
 
+  if
+    (config.options.autosave and type(config.options.should_autosave) == "function")
+    and not config.options.should_autosave()
+  then
+    return
+  end
+
   vim.cmd("mks! " .. e(get_current()))
   vim.g.persisting = true