Sourcing nvim.init does not source required Lua files

Question

I have neovim 0.7.0 running and my .vimrc is at ~/.config/nvim/init.vim

I also have the following file: ~/.config/nvim/lua/statusline.lua with one line of code: print('message from statusline.lua')

Inside init.vim I have:

echo 'from init.vim'
lua require('statusline')

When I start nvim I get both messages printed out ('from init.vim' and 'message from statusline.lua') which is what I would expect.

When I run :source $MYVIMRC I only see 'from init.vim'. I would expect the other message ('message from statusline.lua') to appear as well.

I assume this means any changes I make in statusline.lua will not take effect when I run :source $MYVIMRC. How should I source my init.vim file plus any files it requires without closing and restarting neovim?

Answer 1

Either invalidate cache entry by appending return false to the end of a module.

Or don't use require at all, as you need neither cache nor path search anyway. E.g.

for k, v in ipairs(vim.fn.glob("~/.config/nvim/init.d/*.lua", false, true)) do
    dofile(v)
end

P.S. Lua is not a "config tool". It is a full-featured programming language. If you don't like wasting your time by learning it properly (i.e. reading books and tutorials) you're highly suggested to use VimScript instead. It has some "dark corners" of its own but it is much better suited for writing config.

Answer 2

It depends on the design of your statusline.lua and knowledge about Lua' module loader system.
It looks, because i have to riddle about statusline.lua, that it nothing returns.
Because the return is going into package.loaded and same require in same session looks first there for statusline
So give following a try...

-- statusline.lua
print('message from statusline.lua')
return 'message from package.loaded.statusline'

I have tested above with...

$ lua -i
Lua 5.4.4  Copyright (C) 1994-2022 Lua.org, PUC-Rio
> require('statusline')
message from statusline.lua
message from package.loaded.statusline  ./lua/statusline.lua
> require('statusline')
message from package.loaded.statusline
> require('statusline')
message from package.loaded.statusline

EDIT
Another design for doing something usefull...

-- ~.config/nvim/init.vim
lua print("init.vim")
lua dump = require("dump")

And...

-- ~/.config/nvim/lua/dump.lua
local dump = function(tab)
for key, value in pairs(tab) do
 print(key, '=>', value)
end
end

return dump

Than you have a table viewer and you can see where the functions and tables come from with...

1. :lua dump(_G) -- The global environment table
2. :lua dump(vim) -- The nvim stuff (aka Module)
3. :lua dump(vim.api) -- The nvim API functions (aka Library)
4. :lua dump(jit) -- The Just In Time Compiler ;-)
5. :lua dump([Table Name]) -- Any table that looks interesting
6. :lua dump(package.loaded) -- The required or requireable stuff
   Above function can be executed without defining dump first with: :lua require('dump')(_G)
   So: First require loads dump.lua into package.loaded.dump and returning it and every further require returning: package.loaded.dump
   If you have an sharp eye than take a look on _G.dump thats only a reference (pointer/link) to package.loaded.dump.

EDIT2
Preparing dump.lua for using it with vim.api.nvim_input()

-- ~/.config/nvim/lua/dump.lua
local dump = function(tab)
local tmp = ''
for key, value in pairs(tab) do
 tmp = tmp .. ('%s %s %s\n'):format(key, '=>', value)
end
return tmp
end

return dump

Now the dump function returning a string and the output can be loaded into nvim with: :lua vim.api.nvim_input('i') vim.api.nvim_input(dump(vim.api))

Since many nvim API functions returning a table the dump function becomes handy with...