Neovim freezes in large file when only opening bracket is inserted

[rouge8]

Describe the bug

I'm seeing extremely slow performance inserting ([ around line 150 in a ~1600 line file. It takes ~20 seconds for the [ to insert. 😵

Steps to reproduce

1. Open https://github.com/rouge8/jit.rs/blob/2a3e5dbc7d603f465c1f3083c655613d9a69b87d/tests/merge_test.rs#L147
2. After line 147, type let tree = BTreeMap::from([
3. Wait ~20 seconds after typing the [ before it appears.

Expected behavior

Text should insert instantly.

[p00f]

I can't reproduce this:

rust_slow.mp4

[p00f]

I even tried downloading the entire project, it inserts instantly

[p00f]

(I do have rainbow enabled there, they are all different shades of blue/grey)

[rouge8]

Interesting, it must be an interaction between plugins or something… I’ll try debugging more

[rouge8]

I can still reproduce with a minimal set of plugins:

Plug 'nvim-treesitter/nvim-treesitter', {'do': ':TSUpdate', 'branch': '0.5-compat'}
Plug 'p00f/nvim-ts-rainbow'

What looks different in your recording is that you're autocompleting the ), so you're typing:

let tree = BTreeMap::from()

and then inserting the [. Admittedly that still is slow for me...

[rouge8]

And this is my Treesitter config:

lua <<EOF
require'nvim-treesitter.configs'.setup {
  ensure_installed = "maintained",
  ignore_install = {},
  highlight = {
    enable = true,
    disable = {"rst"},
    additional_vim_regex_highlighting = false,
  },
  rainbow = {
    enable = true,
    extended_mode = true,
    max_file_lines = nil,
  },
  matchup = {
    enable = true,
  },
}
EOF

[p00f]

I can reproduce this when I disable https://github.com/jiangmiao/auto-pairs

[p00f]

fwiw you can get around this without an autopair plugin by inserting the closing bracket first, and if you want to delete the brackets then delete the opening one first

[p00f]

This might be related to steelsojka/pears.nvim#11 (comment)