How do I select *Markdown* emphasis?

[stevenxxiu]

I'd like to be able to select the inside and outside of Markdown emphasis, e.g. for

*foo*
**bar**

I'd like to be able to easily select:

*|foo|*
|*foo*|
**|bar|**
|**bar**|

I'm not quite sure what to add, but I tried adding to ~/.config/nvim/after/queries/markdown/textobjects.scm and ~/.config/nvim/after/queries/markdown_inline/textobjects.scm:

; extends
(emphasis) @text.emphasis

The former triggers an error.

I'd like to set in ~/.config/nvim/lua/plugins/treesitter-textobjects.lua:

-- Markdown
['ae'] = '@text.emphasis',

[chrisgrieser]

I use this in ~/.config/nvim/queries/markdown_inline/textobjects.scm and it works.

; extends
((strong_emphasis) @emphasis.inner
  (#offset! @emphasis.inner 0 2 0 -2))

((emphasis) @emphasis.inner
  (#offset! @emphasis.inner 0 1 0 -1))

(strong_emphasis) @emphasis.outer

(emphasis) @emphasis.outer

[stevenxxiu]

I got the following to work. It includes italics, bold, italics + bold. In ~/.config/nvim/after/queries/markdown_inline/textobjects.scm:

; extends
; ...

(emphasis) @emphasis
(strong_emphasis) @emphasis_strong

In ~/.config/nvim/lua/plugins/treesitter-textobjects.lua:

-- Markdown emphasis
local tree_shared = require('nvim-treesitter-textobjects.shared')

-- From `select.lua` with comments removed.
---@param range Range
---@param selection_mode TSTextObjects.SelectionMode
local function update_selection(range, selection_mode)
  ---@type integer, integer, integer, integer
  local start_row, start_col, end_row, end_col = vim.treesitter._range.unpack4(range)
  selection_mode = selection_mode or 'v'

  local mode = vim.api.nvim_get_mode()
  if mode.mode ~= selection_mode then
    selection_mode = vim.api.nvim_replace_termcodes(selection_mode, true, true, true)
    vim.cmd.normal({ selection_mode, bang = true })
  end

  if end_col == 0 then
    end_row = end_row - 1
    end_col = #vim.api.nvim_buf_get_lines(0, end_row, end_row + 1, true)[1] + 1
  end

  local end_col_offset = 1
  if selection_mode == 'v' and vim.o.selection == 'exclusive' then
    end_col_offset = 0
  end
  end_col = end_col - end_col_offset

  vim.api.nvim_win_set_cursor(0, { start_row + 1, start_col })
  vim.cmd('normal! o')
  vim.api.nvim_win_set_cursor(0, { end_row + 1, end_col })
end

local function select_emphasis(is_outer)
  local opts = { lookahead = true }
  local range1 = tree_shared.textobject_at_point('@emphasis', 'textobjects', nil, nil, opts)
  local range2 = tree_shared.textobject_at_point('@emphasis_strong', 'textobjects', nil, nil, opts)
  local range
  if range1 == nil and range2 == nil then
    return
  elseif range1 ~= nil and range2 ~= nil then
    local start_row_1, start_col_1, start_bytes_1, end_row_1, end_col_1 = unpack(range1)
    local start_row_2, start_col_2, start_bytes_2, end_row_2, end_col_2 = unpack(range2)
    if is_outer then
      if start_bytes_1 < start_bytes_2 then
        range = { start_row_1, start_col_1, end_row_1, end_col_1 }
      else
        range = { start_row_2, start_col_2, end_row_2, end_col_2 }
      end
    else
      if start_row_1 == start_row_2 and end_row_1 == end_row_2 then
        -- Bold and italic
        if start_col_2 - start_col_1 == 1 and end_col_1 - end_col_2 == 1 then
          range = { start_row_1, start_col_2 + 2, end_row_1, end_col_2 - 2 }
        elseif start_col_1 - start_col_2 == 2 and end_col_2 - end_col_1 == 2 then
          range = { start_row_2, start_col_1 + 1, end_row_2, end_col_1 - 1 }
        end
      end
      if range == nil then
        if start_bytes_1 < start_bytes_2 then
          range = { start_row_1, start_col_1 + 1, end_row_1, end_col_1 - 1 }
        else
          range = { start_row_2, start_col_2 + 2, end_row_2, end_col_2 - 2 }
        end
      end
    end
  elseif range1 ~= nil then
    local start_row_1, start_col_1, start_bytes_1, end_row_1, end_col_1 = unpack(range1)
    if is_outer then
      range = { start_row_1, start_col_1, end_row_1, end_col_1 }
    else
      range = { start_row_1, start_col_1 + 1, end_row_1, end_col_1 - 1 }
    end
  elseif range2 ~= nil then
    local start_row_2, start_col_2, start_bytes_2, end_row_2, end_col_2 = unpack(range2)
    if is_outer then
      range = { start_row_2, start_col_2, end_row_2, end_col_2 }
    else
      range = { start_row_1, start_col_1 + 2, end_row_1, end_col_1 - 2 }
    end
  end
  update_selection(range)
end

return {
  -- ...

  -- *Markdown*
  { 'ae', function() select_emphasis(true) end, mode = { 'x', 'o' }, desc = 'outer emphasis', ft = 'markdown' },
  { 'ie', function() select_emphasis(false) end, mode = { 'x', 'o' }, desc = 'inner emphasis', ft = 'markdown' },
  -- ...