Harpoon Setup

[amalavet]

Just thought if anyone wanted to have pinned buffers map to harpoon, this would be helpful

return {
	"romgrk/barbar.nvim",
	dependencies = { "ThePrimeagen/harpoon" },
	config = function()
		local barbar = require("barbar")
		local state = require("barbar.state")
		local render = require("barbar.ui.render")
		local harpoon = require("harpoon")

		barbar.setup({
			hide = {
				inactive = true,
			},
			icons = {
				pinned = { filename = true, buffer_index = true },
				diagnostics = { { enabled = true } },
			},
		})

		local function unpin_all()
			for _, buf in ipairs(state.buffers) do
				local data = state.get_buffer_data(buf)
				data.pinned = false
			end
		end

		local function get_buffer_by_mark(mark)
			for _, buf in ipairs(vim.api.nvim_list_bufs()) do
				local buffer_path = vim.api.nvim_buf_get_name(buf)

				if buffer_path == "" or mark.value == "" then
					goto continue
				end

				local mark_pattern = mark.value:gsub("([%(%)%.%%%+%-%*%?%[%]%^%$])", "%%%1")
				if string.match(buffer_path, mark_pattern) then
					return buf
				end

				local buffer_path_pattern = buffer_path:gsub("([%(%)%.%%%+%-%*%?%[%]%^%$])", "%%%1")
				if string.match(mark.value, buffer_path_pattern) then
					return buf
				end

				::continue::
			end
		end

		local function refresh_all_harpoon_tabs()
			local list = harpoon:list()
			unpin_all()
			for _, mark in ipairs(list.items) do
				local buf = get_buffer_by_mark(mark)
				if buf == nil then
					vim.cmd("badd " .. mark.value)
					buf = get_buffer_by_mark(mark)
				end
				if buf ~= nil then
					state.toggle_pin(buf)
				end
			end
			render.update()
		end

		vim.api.nvim_create_autocmd({ "BufEnter", "BufAdd", "BufLeave", "User" }, {
			callback = refresh_all_harpoon_tabs,
		})
	end,
}

[amalavet]

One other note, I have my harpoon add call the "User" autocmd to update the tabs

		vim.keymap.set("n", "<leader>pa", function()
			harpoon:list():add()
			vim.cmd(":do User")
		end, { desc = "Harpoon: Add file" })

[isseii10]

It might be better not to use ipairs to handle harpoon item deletion.
ipairs stops at nil value.

  local function refresh_all_harpoon_tabs()
    local list = harpoon:list()
    unpin_all()

    for i = 1, list:length() do
      local mark = list.items[i]
      if mark == nil then
        goto continue
      end

      local buf = get_buffer_by_mark(mark)
      if buf == nil then
        vim.cmd("badd " .. mark.value)
        buf = get_buffer_by_mark(mark)
      end
      if buf ~= nil then
        state.toggle_pin(buf)
      end

      ::continue::
    end
    render.update()
  end