How to get the highlight group of the word under the cursor in Neovim with Treesitter installed?

Question

Ok folks, I've tried all these duplicates:

• How to know which highlighting group is used for the background of a word?
• How to identify the highlight groups in use on a particular character?
• How to check what of highlight is the word on cursor?
• Identify syntax region under cursor

But none of them work in for me in Neovim (0.8.2). And the plugin at https://github.com/benknoble/vim-synstax more helpfully reports "No syntax highlight groups under cursor".

I'm testing by putting my cursor in a word in a highlighted PHP doc and then firing the suggested command(s).

I just want my comments to be more readable (they're dark grey on black at the moment).

Is Neovim really different? Is it because I'm using Treesitter?

EDIT

Running without any plugins, the above answers work, it seems to be treesitter that causes the problem.

A minimal config is

use {
'nvim-treesitter/nvim-treesitter',
config = function()
  require('nvim-treesitter.configs').setup({
    highlight = { enable: true }
  })
  end,
}

Note that the problem only seems to occur when the treesitter's config specifies to enable highlight.

Answer 1

From 'nvim-treesitter/playground', there is the command

:TSHighlightCapturesUnderCursor

which does exactly this, presenting a nice popup at your cursor location. It works similarly to

:TSNodeUnderCursor

to get the tree-sitter node at your cursor location.

Answer 2

According to the closed issue at
https://github.com/nvim-treesitter/nvim-treesitter/issues/1654#issuecomment-893756730
Treesitter messes up synstack().

The only way to get a function to do something similar is through installing a 2nd plugin, nvim-treesitter/playground and writing a lua function, like the one at https://github.com/urbainvaes/vim-macaw/commit/be633f850fb54ed71cc6a1d46ee788380b7393b5

Manually, once you have playground installed you can start it up with :TSPlaygroundToggle then in the playground window press i to show highlight groups.