fix: save_extra_cmds only works with single string

`Lib.run_hook_cmds` returns a table of tables (one for reach hook cmd
that was run). In `save_extra_cmds`, `vim.fn.writefile` expects a table
strings and if any of those strings contain newlines, they're
translated into nul characters. That means that there was no way to
return more than one line from a `save_extra_cmds` hook function.

To fix, we combine the results across all `save_extra_cmds` hooks and we
now support a `save_extra_cmds` hook returning either a string (possibly
with newlines) or table. If a hook returns a string then any newlines
will be used to split the string into individual line entries in the
table passed to `vim.fn.writefile`. If a hook returns a table, then each
of the values of the table will be added to the table passed to
`vim.fn.writefile` (the same newline splitting will also happen)

README.md

@@ -281,7 +281,7 @@ require('auto-session').setup({
 Command hooks exist in the format: {hook_name}
 
 - `{pre_save}`: executes _before_ a session is saved
-- `{save_extra}`: executes _after_ a session is saved, return string will save to `*x.vim`, reference `:help mks`
+- `{save_extra}`: executes _after_ a session is saved, saves returned string or table to `*x.vim`, reference `:help mks`
 - `{post_save}`: executes _after_ a session is saved
 - `{pre_restore}`: executes _before_ a session is restored
 - `{post_restore}`: executes _after_ a session is restored

lua/auto-session/init.lua

@@ -355,12 +355,19 @@ end
 ---@return boolean Returns whether extra commands were saved
 local function save_extra_cmds_new(session_path)
  local data = AutoSession.run_cmds "save_extra"
- if not data then
+ local extra_file = string.gsub(session_path, "%.vim$", "x.vim")
+
+ -- data is a table of strings or tables, one for each hook function
+ -- need to combine them all here into a single table of strings
+ local data_to_write = Lib.flatten_table_and_split_strings(data)
+
+ if not data_to_write or vim.tbl_isempty(data_to_write) then
+ -- Have to delete the file just in case there's an old file from a previous save
+ vim.fn.delete(extra_file)
  return false
  end
 
- local extra_file = string.gsub(session_path, "%.vim$", "x.vim")
- if vim.fn.writefile(data, extra_file) ~= 0 then
+ if vim.fn.writefile(data_to_write, extra_file) ~= 0 then
  return false
  end
 

lua/auto-session/lib.lua

@@ -563,4 +563,45 @@ function Lib.run_hook_cmds(cmds, hook_name)
  return results
 end
 
+---Split any strings on newlines and add each one to the output table
+---Also flatten any embedded tables and and their values into the root table
+---(non recursive so only one level deep)
+---@param input table|nil
+---@return table The flattened table
+function Lib.flatten_table_and_split_strings(input)
+ local output = {}
+
+ if not input then
+ return output
+ end
+
+ local function add_value_to_output(value)
+ Lib.logger.debug("value: ", value)
+ if value == nil then
+ return
+ end
+
+ local value_type = type(value)
+ if value_type == "number" then
+ table.insert(output, value)
+ elseif value_type == "string" then
+ for s in value:gmatch "[^\r\n]+" do
+ table.insert(output, s)
+ end
+ end
+ end
+
+ for _, value in pairs(input) do
+ if type(value) == "table" then
+ for _, subvalue in pairs(value) do
+ add_value_to_output(subvalue)
+ end
+ else
+ add_value_to_output(value)
+ end
+ end
+
+ return output
+end
+
 return Lib

tests/extra_sesssion_commands_spec.lua

@@ -6,11 +6,15 @@ describe("Config with extra session commands", function()
  local save_extra_cmds_called = false
  local as = require "auto-session"
  local Lib = require "auto-session.lib"
+ -- WARN: this test calls setup again later to change save_extra_cmds
  as.setup {
  save_extra_cmds = {
  function()
  save_extra_cmds_called = true
- return [[echo "hello world"]]
+ return [[
+ lua vim.g.extraCmdsTest = 1
+ lua vim.g.extraCmdsTest2 = 2
+ ]]
  end,
  },
  -- log_level = "debug",
@@ -36,7 +40,78 @@ describe("Config with extra session commands", function()
  TL.assertSessionHasFile(TL.default_session_path, TL.test_file)
 
  -- Make sure extra commands are there
- assert.True(TL.fileHasString(default_extra_cmds_path, 'echo \\"hello world\\"'))
+ assert.True(TL.fileHasString(default_extra_cmds_path, "lua vim.g.extraCmdsTest = 1"))
+ end)
+
+ it("can restore a default session with extra commands", function()
+ vim.g.extraCmdsTest = 0
+ vim.g.extraCmdsTest2 = 0
+
+ assert.True(as.RestoreSession())
+
+ assert.True(vim.g.extraCmdsTest == 1)
+ assert.True(vim.g.extraCmdsTest2 == 2)
+ end)
+
+ it("can clear x.vim if there are no extra commands", function()
+ -- make sure the file is there now
+ assert.equals(1, vim.fn.filereadable(default_extra_cmds_path))
+
+ -- remove the handler
+ as.setup {
+ save_extra_cmds = nil,
+ }
+
+ -- generate default session
+ assert.True(as.AutoSaveSession())
+
+ -- Make sure the session was created
+ assert.equals(1, vim.fn.filereadable(TL.default_session_path))
+
+ -- make sure the extra commands file was removed
+ assert.equals(0, vim.fn.filereadable(default_extra_cmds_path))
+ end)
+
+ TL.clearSessionFilesAndBuffers()
+
+ it("can save a default session with extra commands in a table", function()
+ vim.cmd("e " .. TL.test_file)
+
+ save_extra_cmds_called = false
+
+ as.setup {
+ save_extra_cmds = {
+ function()
+ save_extra_cmds_called = true
+ return { "lua vim.g.extraCmdsTest = 1", "lua vim.g.extraCmdsTest2 = 2" }
+ end,
+ },
+ }
+
+ -- generate default session
+ assert.True(as.AutoSaveSession())
+
+ -- Make sure the session was created
+ assert.equals(1, vim.fn.filereadable(TL.default_session_path))
+ assert.equals(1, vim.fn.filereadable(default_extra_cmds_path))
+
+ assert.True(save_extra_cmds_called)
+
+ -- Make sure the session has our buffer
+ TL.assertSessionHasFile(TL.default_session_path, TL.test_file)
+
+ -- Make sure extra commands are there
+ assert.True(TL.fileHasString(default_extra_cmds_path, "lua vim.g.extraCmdsTest = 1"))
+ end)
+
+ it("can restore a default session with extra commands", function()
+ vim.g.extraCmdsTest = 0
+ vim.g.extraCmdsTest2 = 0
+
+ assert.True(as.RestoreSession())
+
+ assert.True(vim.g.extraCmdsTest == 1)
+ assert.True(vim.g.extraCmdsTest2 == 2)
  end)
 
  local session_name = "x"
@@ -61,7 +136,7 @@ describe("Config with extra session commands", function()
  TL.assertSessionHasFile(session_path, TL.test_file)
 
  -- Make sure extra commands are there
- assert.True(TL.fileHasString(extra_cmds_path, 'echo \\"hello world\\"'))
+ assert.True(TL.fileHasString(extra_cmds_path, "lua vim.g.extraCmdsTest = 1"))
  end)
 
  it("can correctly differentiate x.vim session and xx.vim custom commands", function()

tests/lib_spec.lua

@@ -183,4 +183,36 @@ describe("Lib / Helper functions", function()
  assert.equals("", Lib.current_session_name())
  assert.equals("", Lib.current_session_name(true))
  end)
+
+ it("flatten_table_and_split_string() works with strings and tables", function()
+ local data = { "one\ntwo\nthree\n" }
+ local output = Lib.flatten_table_and_split_strings(data)
+
+ assert.equals(#output, 3)
+ assert.equals(output[1], "one")
+ assert.equals(output[2], "two")
+ assert.equals(output[3], "three")
+
+ data = { { "a", "b", "c\nd" }, "e", "f\ng" }
+ output = Lib.flatten_table_and_split_strings(data)
+
+ assert.equals(#output, 7)
+ assert.equals(output[1], "a")
+ assert.equals(output[2], "b")
+ assert.equals(output[3], "c")
+ assert.equals(output[4], "d")
+ assert.equals(output[5], "e")
+ assert.equals(output[6], "f")
+ assert.equals(output[7], "g")
+
+ data = {}
+ output = Lib.flatten_table_and_split_strings(data)
+
+ assert.True(vim.tbl_isempty(output))
+
+ data = { {} }
+ output = Lib.flatten_table_and_split_strings(data)
+
+ assert.True(vim.tbl_isempty(output))
+ end)
 end)