This is not a complete list of changes. Just what I have noticed. Complete release note for nvim 0.8 is here.

# Nvim-lsp update

## server capabilities

The old client.resolved_capabilities table is changed to client.server_capabilities, and the keys have also changed.

oldnew
client.resolved_capabilities.document_formattingclient.server_capabilities.documentFormattingProvider
client.resolved_capabilities.document_range_formattingclient.server_capabilities.documentRangeFormattingProvider
client.resolved_capabilities.document_highlightclient.server_capabilities.documentHighlightProvider

To check the complete server_capabilities table for a file, open that file, and run the following command:

lua =vim.lsp.get_active_clients()[1].server_capabilities


It will print the full table.

## method changes

Lsp format method has changed, both vim.lsp.buf.formatting_sync() and vim.lsp.buf.formatting() are deprecated. Now we should use vim.lsp.buf.format(), which has async param (default false) to control whether formatting should be async.

vim.lsp.buf.range_formatting() is also deprecated. Now the formatexpr option for your buffer will be set to vim.lsp.formatexpr() if it is not set by user. To format the selected code, you just press gq instead.

## others

This reddit post also shares other changes, like the LspAttach and LspDetach events, tagfunc, omnifunc support etc.

# Options and defaults

## mouse

Mouse is enabled by default1 and mousescroll option is added, you can define how many lines to scroll like this:

set mousescroll=ver:1,hor:5


Also if you set mousemodel=popup, nvim now shows a popup menu. To disable this, just use set mousemodel=extend.

## winbar/cmdline

Nvim has added a winbar option, it is like statusline, but on top of your window.

For cmdline, you can use set cmdheight=0 to hide it completely, and it will show when you run some commands. You may see the press enter message often when some messages are printed, which may be annoying. There is also a plugin noice.nvim made to ease the issue.

## clickable statusline and winbar

Nvim 0.8 adds clickable element in statusline and winbar, the syntax is %@some_func@text_shown%X. some_func is the function that will be run when you click text_shown.

Here is a demo in Lua:

function Hello(...)
local arg = {...}
arg = vim.inspect(arg)
print('hello world, arg:', arg)
end

local w = vim.fn.winwidth(0)
local pos = math.floor(w/2)

local stl = string.rep(" ", pos)
stl = stl .. "%5@v:lua.Hello@click me%X"

vim.o.statusline=stl


Save it as test.lua, then run nvim -u test.lua. Click the text click me on the statusline, you will see the message printed.

## State dir change

The directory for storing shada, undo, swap, log, lsp-log is changed from ~/.local/share/nvim to ~/.local/state/nvim. Check the exact directory with command echo stdpath('state'). See also https://github.com/neovim/neovim/issues/14090#issuecomment-1125055183.

## filetype.lua by default

The new filetype.lua system will be used by default, and the following config should be removed:

vim.g.do_filetype_lua = 1


## * and # can search selected text

* and # can now search selected text literally2. Previously I was using vim-asterisk together with nvim-hlslens. Now I can remove vim-asterisk, with a little hack:

keymap.set("n", "*", "", {
callback = function()
vim.fn.execute("normal! *N")
hlslens.start()
end,
})
keymap.set("n", "#", "", {
callback = function()
vim.fn.execute("normal! #N")
hlslens.start()
end,
})


It does has limitations, for example, you can not search multi-line selections.

# Treesitter

Now the treesitter parser for vim, lua, and help is enabled by default. But currently the help doc parser seems to have issues regarding conceal, as reported in issue here.

# Misc

## Man command improve

• It is implemented in lua and should be faster compared to its old vim implementation3.
• In buffer opened by :Man, you can type gO to show the argument list view4.

## Check command or map location

If the lua mapping is defined the via callback, we can now see its defined location.

vim.keymap.set("n", "<leader>sv", "", {
silent = true,
callback = function()
vim.cmd([[
update $MYVIMRC source$MYVIMRC
]])
vim.notify("Nvim config successfully reloaded!", vim.log.levels.INFO, { title = "nvim-config" })
end,
})


For example, I have the above mapping, now I can see where it is defined with verb nmap ,sv (my leader key is comma).

However, for mapping defined via right hand side string, we only see that the mapping is set from lua, but not the exact location.

By right hand side string, I mean mapping like the following:

vim.keymap.set("n", "<leader>p", "mo<ESC>p", { desc = "paste below current line" })


This is unlike the mapping defined in vim script. To see the mapping location, start nvim with nvim -V1, then use the :verbose command again, we should see the mapping location.

This is still not perfect and confusing even for experienced users like me.

## vim.fs module

vim.fs (:h lua-fs) aims to provide some functions for common path operations like os.path in Python. For example:

local d = vim.fs.dirname('~/.config/nvim/init.lua')
print(d)


## startup time for require

Now time for require() is also shown for nvim --startuptime time.log like this:

....
206.153  000.101  000.101: require('lualine_require')
206.558  000.632  000.531: require('lualine')
214.826  000.150  000.150: require('lualine.utils.mode')
216.924  000.140  000.140: require('lualine.extensions.nerdtree')
217.125  011.338  010.417: require('config.statusline')
....


## change of support for old systems

### Linux

Nvim build env for Linux is updated to Ubuntu 20.04, so the nightly release may not work for old machines any more5. I tested latest nvim nightly on CentOS 7.4, and it can not work anymore, with the following error: