expand.lua

local ts_utils = require('nvim-treesitter.ts_utils')

local get_master_node = function()
    local node = ts_utils.get_node_at_cursor()
    if not node then
        error('Cannot get node at cursor')
    end

    -- When in normal mode, find the smallest node starting at the cursor position
    local root = ts_utils.get_root_for_node(node)
    local start_row = node:start()
    local parent = node:parent()
    while parent ~= nil and parent ~= root and parent:start() == start_row do
        node = parent
        parent = node:parent()
    end

    return node
end

local function selectRange()
    local node = get_master_node()
    local bufnr = vim.api.nvim_get_current_buf()
    ts_utils.update_selection(bufnr, node)
end

-- Define vim command
vim.api.nvim_create_user_command('SelectRange', selectRange, { range = true })

-- Keymap to ctrl w on n and v mode
vim.api.nvim_set_keymap('n', '<C-w>', ':SelectRange<CR>', { noremap = true, silent = true })
vim.api.nvim_set_keymap('v', '<C-w>', ':SelectRange<CR>', { noremap = true, silent = true })