Harpoon X Bufferline Neovim

config.lua

-- This example shows how to integrate Bufferline with Harpoon
-- The goal is to get bufferline to show only the files marked by harpoon, with the correct number
-- I use <C-w>{1..N} to navigate between the harpoon buffers, my harpoon config is also included
-- I have also setup an autocommand in order to open all the harpoon buffers when launching neovim, it is at the bottom of the file
-- NOTE: this guide relies on you using the lazy package manager

-- bufferline.nvim
-- helper functions:
local function get_marked_buffers()
  local mark = require("harpoon.mark")
  local harpoon_buffers = {}
  local current_idx = 1

  while mark.get_marked_file_name(current_idx) do
    harpoon_buffers[current_idx] = mark.get_marked_file_name(current_idx)
    current_idx = current_idx + 1
  end

  return harpoon_buffers
end

local function get_index_of_value(table, value)
  local index = nil
  for i, v in pairs(table) do
    if v == value then
      index = i
      break
    end
  end

  return index
end


-- config itself, the options required for the itegration are first, the rest are my personal settings
return {
  "akinsho/bufferline.nvim",
  dependencies = { "theprimeagen/harpoon" },
  opts = {
    options = {
      -- INTEGRATION
      numbers = function(buffer)
        -- get the harpoon buffers and the name of the buffer
        local buf_name = vim.fn.bufname(buffer.id)
        local harpoon_buffers = get_marked_buffers()

        return get_index_of_value(harpoon_buffers, buf_name) or ""
      end,
      custom_filter = function(buf_number)
        -- get the harpoon buffers and the name of the buffer
        local harpoon_buffers = get_marked_buffers()
        local buf_name = vim.fn.bufname(buf_number)

        local idx = get_index_of_value(harpoon_buffers, buf_name)

        if idx then
          return true
        end
        return false
      end,
      sort_by = function (buffer_a, buffer_b)
        -- get the harpoon buffers and the names of the buffers
        local harpoon_buffers = get_marked_buffers()
        local buf_name_a = vim.fn.bufname(buffer_a.id)
        local buf_name_b = vim.fn.bufname(buffer_b.id)

        local idx_a = get_index_of_value(harpoon_buffers, buf_name_a)
        local idx_b = get_index_of_value(harpoon_buffers, buf_name_b)

        return idx_a < idx_b
      end,
      
      -- PERSONAL SETTINGS
      -- stylua: ignore
      close_command = function(n) require("mini.bufremove").delete(n, false) end,
      -- stylua: ignore
      right_mouse_command = function(n) require("mini.bufremove").delete(n, false) end,
      diagnostics = "nvim_lsp",
      always_show_bufferline = false,
      diagnostics_indicator = function(_, _, diag)
        local icons = require("lazyvim.config").icons.diagnostics
        local ret = (diag.error and icons.Error .. diag.error .. " " or "")
          .. (diag.warning and icons.Warn .. diag.warning or "")
        return vim.trim(ret)
      end,
    },
  },
  event = "VeryLazy",
  keys = {
    { "<leader>bp", "<Cmd>BufferLineTogglePin<CR>", desc = "Toggle pin" },
    { "<leader>bP", "<Cmd>BufferLineGroupClose ungrouped<CR>", desc = "Delete non-pinned buffers" },
  },
}

-- harpoon.lua
local HARPOON_BUFFERS = 10

return {
  "theprimeagen/harpoon",
  config = function()
    vim.keymap.set("n", "<leader>a", require("harpoon.mark").add_file, { desc = "[A]dd harpoon file" })
    vim.keymap.set("n", "<C-w>e", require("harpoon.ui").toggle_quick_menu, { desc = "[W]indow [E]dit harpoon" })
    for i = 1, HARPOON_BUFFERS do
      vim.keymap.set("n", "<C-w>" .. i, function() require("harpoon.ui").nav_file(i) end,
        { desc = "Harpoon [W]indow " .. i })
    end
  end,
}


-- autocommands.lua
vim.api.nvim_create_autocmd("User", {
  pattern = "LazyVimStarted",
  once = true,
  callback = function()
    -- this needs to be deffered for some other stuff to load, I am not sure there is a better event
    vim.defer_fn(function()
      local mark = require("harpoon.mark")
      local harpoon_buffers = {}
      local current_idx = 1

      while mark.get_marked_file_name(current_idx) do
        harpoon_buffers[current_idx] = mark.get_marked_file_name(current_idx)
        current_idx = current_idx + 1
      end

      -- for each of the harpoon buffers we open them
      for _, buffer in reverse_iter(harpoon_buffers) do
        vim.cmd("silent edit " .. buffer)
      end

      require("harpoon.ui").nav_file(1)
    end, 10)
  end,
})