Deferring of all NeoVim diagnostics

NeoVim has an option (update_in_insert) to defer displaying diagnostics when in insert mode. When enabled, diagnostics are disabled when entering insert mode, and re-enabled when leaving insert mode. This reduces the amount of noise caused by irrelevant diagnostics.

Unfortunately, this option only applies to signs, underlines, and virtual text. If you display the number of diagnostics in your statusline, automatically populate location/quickfix lists with new diagnostics, or really do anything else with the diagnostics you're out of luck.

In addition, update_in_insert doesn't apply to normal mode, meaning any changes made in normal mode may result in new diagnostics being displayed.

Finally, when a popup menu is displayed (such as when using a completefunc), Vim enters normal mode. If you then insert text by cycling through the available items, new diagnostics are displayed.

It all comes down to the same problem: language servers typically produce diagnostics as you type, but diagnostics are rarely useful when you are still editing text.

nvim-dd tries to solve this problem by deferring all diagnostics. This means no annoying diagnostics while you are typing, and no need to handle deferring every time you use the vim.diagnostic API yourself (e.g. in a statusline).

To illustrate this, here's what it looks like when you edit a Lua file without nvim-dd:

before.webm

Note how the statusline changes as we're typing, and the new signs/underlines that are produced.

Here's what it looks like with nvim-dd:

after.webm

While the statusline and signs/underlines still change, they change less frequently and not while we're in insert mode.

How it works

nvim-dd hijacks vim.lsp.diagnostic.on_publish_diagnostics. Every time new diagnostics come in, nvim-dd checks what to do. If you are in insert mode or a popup menu is visible, the diagnostics are cached in a table. If you are not in insert mode, the diagnostics are scheduled for publishing to NeoVim using a timer. New changes made will cancel the existing timer. When exiting insert mode, nvim-dd schedules all cached diagnostics using the same timer mechanism.

The result of this setup is that you can type all you want in insert mode, and never be bothered by new (irrelevant) diagnostics. When leaving insert mode you aren't immediately bombarded with new diagnostics. When editing in normal mode, diagnostics are only produced a certain time after your last edit.

This approach comes with one downside: if you use a plugin that expects diagnostics to be available immediately after the language server sends them to NeoVim, said plugin probably won't work.

Requirements

NeoVim 0.6 or newer is required, as this plugin uses the new vim.diagnostic API. As of October 2021 this means you need to build NeoVim from the master branch.

Installation

First install this plugin using your plugin manager of choice. For example, when using vim-plug use the following:

Plug 'https://gitlab.com/yorickpeterse/nvim-dd.git'

Once installed, add the following Lua snippet to your init.lua:

require('dd').setup()

And that's it!

Configuration

You can configure nvim-dd as follows:

require('dd').setup({
  -- The time to wait before displaying newly produced diagnostics.
  timeout = 1000
})

License

All source code in this repository is licensed under the Mozilla Public License version 2.0, unless stated otherwise. A copy of this license can be found in the file "LICENSE".