Change init.vim to init.lua

init.lua

vim.cmd("set encoding=UTF-8")
vim.cmd("set number")
vim.cmd("set ruler")
vim.cmd("set visualbell")
vim.cmd("set wrap")
vim.cmd("set tabstop=4")
vim.cmd("set shiftwidth=4")
vim.cmd("set expandtab")

-- make sure the packer plugin manager is installed
local ensure_packer = function()
    local fn = vim.fn
    local install_path = fn.stdpath("data") .. "/site/pack/packer/start/packer.nvim"
    if fn.empty(fn.glob(install_path)) > 0 then
        fn.system({ "git", "clone", "--depth", "1", "https://github.com/wbthomason/packer.nvim", install_path })
        vim.cmd([[packadd packer.nvim]])
        return true
    end
    return false
end

local packer_bootstrap = ensure_packer()

require("packer").startup(function(use)
    -- Packer can manage itself
    use("wbthomason/packer.nvim")
    -- Collection of common configurations for the Nvim LSP client
    use("neovim/nvim-lspconfig")
    -- Visualize lsp progress
    use({
        "j-hui/fidget.nvim",
        config = function()
            require("fidget").setup()
        end
    })

    -- Autocompletion framework
    use("hrsh7th/nvim-cmp")
    use({
        -- cmp LSP completion
        "hrsh7th/cmp-nvim-lsp",
        -- cmp Snippet completion
        "hrsh7th/cmp-vsnip",
        -- cmp Path completion
        "hrsh7th/cmp-path",
        "hrsh7th/cmp-buffer",
        after = { "hrsh7th/nvim-cmp" },
        requires = { "hrsh7th/nvim-cmp" },
    })
    -- See hrsh7th other plugins for more great completion sources!
    -- Snippet engine
    use('hrsh7th/vim-vsnip')
    -- Adds extra functionality over rust analyzer
    use("simrat39/rust-tools.nvim")

    -- Optional
    use("nvim-lua/popup.nvim")
    use("nvim-lua/plenary.nvim")
    use("nvim-telescope/telescope.nvim")

    -- Some color scheme other then default
    use("sainnhe/gruvbox-material")

    -- lualine
    use {
        'nvim-lualine/lualine.nvim',
        requires = { 'kyazdani42/nvim-web-devicons', opt = true }
    }

    -- lua-tree
    use {
        'nvim-tree/nvim-tree.lua',
        requires = {
            'nvim-tree/nvim-web-devicons', -- optional, for file icons
        }
    }
end)


-- the first run will install packer and our plugins
if packer_bootstrap then
    require("packer").sync()
    return
end

vim.api.nvim_command('colorscheme gruvbox-material')
require('lualine').setup {
    options = { theme  = 'gruvbox-material' },
}

-- disable netrw at the very start of your init.lua (strongly advised)
vim.g.loaded_netrw = 1
vim.g.loaded_netrwPlugin = 1

-- set termguicolors to enable highlight groups
vim.opt.termguicolors = true

-- OR setup with some options
require("nvim-tree").setup({
    respect_buf_cwd = true,
    update_focused_file = {
        enable = true,
        update_root = true
    },
    open_on_setup = true,
    open_on_setup_file = true,
    open_on_tab = false,
    view = {
        side = "left",
        width = 30,
        auto_resize = true
    },
    sort_by = "case_sensitive",
    view = {
        adaptive_size = true,
        mappings = {
            list = {
                { key = "u", action = "dir_up" },
            },
        },
    },
    renderer = {
        group_empty = true,
    },
    filters = {
        dotfiles = false,
    },
})

-- require("nvim-tree").toggle(false, true, vim.api.nvim_buf_get_name(0))

-- close if it's the last one
--vim.api.nvim_create_autocmd("BufEnter", {
--    nested = true,
--    callback = function()
--        if #vim.api.nvim_list_wins() == 1 and vim.api.nvim_buf_get_name(0):match("NvimTree_") ~= nil then
--            vim.cmd "quit"
--        end
--    end
--})

-- Set completeopt to have a better completion experience
-- :help completeopt
-- menuone: popup even when there's only one match
-- noinsert: Do not insert text until a selection is made
-- noselect: Do not auto-select, nvim-cmp plugin will handle this for us.
vim.o.completeopt = "menuone,noinsert,noselect"

-- Avoid showing extra messages when using completion
vim.opt.shortmess = vim.opt.shortmess + "c"

local function on_attach(client, buffer)
    -- This callback is called when the LSP is atttached/enabled for this buffer
    -- we could set keymaps related to LSP, etc here.
end

-- Configure LSP through rust-tools.nvim plugin.
-- rust-tools will configure and enable certain LSP features for us.
-- See https://github.com/simrat39/rust-tools.nvim#configuration
local opts = {
    tools = {
        runnables = {
            use_telescope = true,
        },
        inlay_hints = {
            auto = true,
            show_parameter_hints = false,
            parameter_hints_prefix = "",
            other_hints_prefix = "",
        },
    },

    -- all the opts to send to nvim-lspconfig
    -- these override the defaults set by rust-tools.nvim
    -- see https://github.com/neovim/nvim-lspconfig/blob/master/CONFIG.md#rust_analyzer
    server = {
        -- on_attach is a callback called when the language server attachs to the buffer
        on_attach = on_attach,
        settings = {
            -- to enable rust-analyzer settings visit:
            -- https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/user/generated_config.adoc
            ["rust-analyzer"] = {
                -- enable clippy on save
                checkOnSave = {
                    command = "clippy",
                },
            },
        },
    },
}

require("rust-tools").setup(opts)

-- Setup Completion
-- See https://github.com/hrsh7th/nvim-cmp#basic-configuration
local cmp = require("cmp")
cmp.setup({
    preselect = cmp.PreselectMode.None,
    snippet = {
        expand = function(args)
            vim.fn["vsnip#anonymous"](args.body)
        end,
    },
    mapping = {
        ["<C-p>"] = cmp.mapping.select_prev_item(),
        ["<C-n>"] = cmp.mapping.select_next_item(),
        -- Add tab support
        ["<S-Tab>"] = cmp.mapping.select_prev_item(),
        ["<Tab>"] = cmp.mapping.select_next_item(),
        ["<C-d>"] = cmp.mapping.scroll_docs(-4),
        ["<C-f>"] = cmp.mapping.scroll_docs(4),
        ["<C-Space>"] = cmp.mapping.complete(),
        ["<C-e>"] = cmp.mapping.close(),
        ["<CR>"] = cmp.mapping.confirm({
            behavior = cmp.ConfirmBehavior.Insert,
            select = true,
        }),
    },

    -- Installed sources
    sources = {
        { name = "nvim_lsp" },
        { name = "vsnip" },
        { name = "path" },
        { name = "buffer" },
    },
})

local keymap_opts = { buffer = buffer }
-- Code navigation and shortcuts
vim.keymap.set("n", "<c-]>", vim.lsp.buf.definition, keymap_opts)
vim.keymap.set("n", "K", vim.lsp.buf.hover, keymap_opts)
vim.keymap.set("n", "gD", vim.lsp.buf.implementation, keymap_opts)
vim.keymap.set("n", "<c-k>", vim.lsp.buf.signature_help, keymap_opts)
vim.keymap.set("n", "1gD", vim.lsp.buf.type_definition, keymap_opts)
vim.keymap.set("n", "gr", vim.lsp.buf.references, keymap_opts)
vim.keymap.set("n", "g0", vim.lsp.buf.document_symbol, keymap_opts)
vim.keymap.set("n", "gW", vim.lsp.buf.workspace_symbol, keymap_opts)
vim.keymap.set("n", "gd", vim.lsp.buf.definition, keymap_opts)


-- Set updatetime for CursorHold
-- 300ms of no cursor movement to trigger CursorHold
vim.opt.updatetime = 100

-- Show diagnostic popup on cursor hover
local diag_float_grp = vim.api.nvim_create_augroup("DiagnosticFloat", { clear = true })
vim.api.nvim_create_autocmd("CursorHold", {
    callback = function()
        vim.diagnostic.open_float(nil, { focusable = false })
    end,
    group = diag_float_grp,
})

-- Goto previous/next diagnostic warning/error
vim.keymap.set("n", "g[", vim.diagnostic.goto_prev, keymap_opts)
vim.keymap.set("n", "g]", vim.diagnostic.goto_next, keymap_opts)

-- have a fixed column for the diagnostics to appear in
-- this removes the jitter when warnings/errors flow in
vim.wo.signcolumn = "yes"