Why is indentation on Github different from indentation in my Neovim?

Question

After committing I realised that indents on GitHub show differently from what I see in Neovim.

I also noticed that all formatting (including indentation) is reset when an error occurs when loading the lazy package manager, the code in this case looks the same as in GitHub

I want my editor not to lie me so it looks exactly the same in all editors.

What am I missing? :)

Neovim:

local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
  vim.fn.system({
    "git",
    "clone",
    "--filter=blob:none",
    "https://github.com/folke/lazy.nvim.git",
    "--branch=stable", -- latest stable release
    lazypath,
  })
end
vim.opt.rtp:prepend(lazypath)

require("lazy").setup({
  -- AUTOPAIRS
  {
    'windwp/nvim-autopairs',
    event = "InsertEnter",
    opts = {}
  },
  -- TELESCOPE
  {
    'nvim-telescope/telescope.nvim', tag = '0.1.5',
    dependencies = { 'nvim-lua/plenary.nvim' },

    config = function()
      local actions = require("telescope.actions")
      require("telescope").setup{
        defaults = {
          mappings = {
            i = {
              ["<C-k>"] = actions.move_selection_previous, -- move to prev result
              ["<C-j>"] = actions.move_selection_next, -- move to next result
            },
          },
        },
      }
      local builtin = require('telescope.builtin')
      vim.keymap.set('n', '<leader>ff', builtin.find_files, {})
      vim.keymap.set('n', '<leader>gf', builtin.git_files, {})

    end
  },
  -- TREE-SITTER
  {
    "nvim-treesitter/nvim-treesitter",
    build = ":TSUpdate",
    config = function () 
      local configs = require("nvim-treesitter.configs")

      configs.setup({
        ensure_installed = { "html", "css", "javascript", "typescript", "lua", "vim" },
        sync_install = false,
        highlight = { enable = true },
        indent = { enable = true },  
      })
    end
  },
  -- COLORSCHEME
  {
    "folke/tokyonight.nvim",
    lazy = false,
    priority = 1000,
    opts = {},
    config = function()
      require("tokyonight").setup({
        transparent = true
      })
      vim.cmd[[colorscheme tokyonight-moon]]
    end
  }
})

GitHub:

local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
    vim.fn.system({
        "git",
        "clone",
        "--filter=blob:none",
        "https://github.com/folke/lazy.nvim.git",
        "--branch=stable", -- latest stable release
        lazypath,
    })
end
vim.opt.rtp:prepend(lazypath)

require("lazy").setup({
    -- AUTOPAIRS
    {
        'windwp/nvim-autopairs',
    event = "InsertEnter",
        opts = {}
    },
    -- TELESCOPE
    {
        'nvim-telescope/telescope.nvim', tag = '0.1.5',
        dependencies = { 'nvim-lua/plenary.nvim' },

        config = function()
            local actions = require("telescope.actions")
            require("telescope").setup{
                defaults = {
                    mappings = {
                        i = {
                            ["<C-k>"] = actions.move_selection_previous, -- move to prev result
                            ["<C-j>"] = actions.move_selection_next, -- move to next result
                        },
                    },
                },
            }
            local builtin = require('telescope.builtin')
            vim.keymap.set('n', '<leader>ff', builtin.find_files, {})
            vim.keymap.set('n', '<leader>gf', builtin.git_files, {})

        end
    },
    -- TREE-SITTER
    {
        "nvim-treesitter/nvim-treesitter",
        build = ":TSUpdate",
        config = function () 
            local configs = require("nvim-treesitter.configs")

            configs.setup({
                ensure_installed = { "html", "css", "javascript", "typescript", "lua", "vim" },
                sync_install = false,
                highlight = { enable = true },
                indent = { enable = true },  
            })
        end
    },
    -- COLORSCHEME
    {
        "folke/tokyonight.nvim",
    lazy = false,
    priority = 1000,
        opts = {},
        config = function()
            require("tokyonight").setup({
                transparent = true
            })
            vim.cmd[[colorscheme tokyonight-moon]]
        end
    }
})

options.lua:

vim.g.mapleader = " "

vim.wo.number = true
vim.o.mouse = 'a'
vim.o.termguicolors = true

vim.o.expandtab = false        
vim.o.shiftwidth = 2         
vim.o.tabstop = 2             
vim.o.smartindent = true

Answer 1

You indent your code with tab (expandtab = false). You have configured Neovim to show tab as 2 spaces (tabstop = 2, shiftwidth = 2).

It seems that GitHub display tab as 8 spaces.

If you want to align both you can adapt your configuration to match GitHub and replace 2 by 8.

vim.o.tabstop = 8
vim.o.shiftwidth = 8

If you want to convert your text to use space instead you can:

Change your configuration:

vim.o.expandtab = true

Convert tab into spaces by running the following Vim command:

:retab

Answer 2

Note that almost every tool that renders text with tabs has a way to configure tab size. It's the case with neo/vim, but also with github.

See the current official documentation and its screenshots. You could also append ?ts=2 to the url of the file you're consulting via github interface -- see this Q/A on SO.

I still prefer working without tabulations -- as some tools are really cumbersome to configure on this topic. See Vivian's answer for the how.

Answer 3

Instead of just telling Vim directly to use 2-tab spaces, use an EditorConfig file to tell many editors—including Neovim and GitHub—your preferences. Create a file named .editorconfig at the root of your repository and put inside it:

root = true

[*]
indent_style = tab
tab_width = 2