add nvim-ufo

.config/nvim/lua/pluginconf/lspconf.lua

@@ -1,6 +1,11 @@
 local lspc = require "lspconfig"
 local caps = require("cmp_nvim_lsp").default_capabilities(vim.lsp.protocol.make_client_capabilities())
 
+caps.textDocument.foldingRange = {
+    dynamicRegistration = false,
+    lineFoldingOnly = true,
+}
+
 local lua_runtime_path = vim.split(package.path, ";")
 table.insert(lua_runtime_path, "lua/?.lua")
 table.insert(lua_runtime_path, "lua/?/init.lua")

.config/nvim/lua/pluginconf/nvim_ufo.lua

@@ -0,0 +1,30 @@
+local ufo = require "ufo"
+local ts_parsers = require "nvim-treesitter.parsers"
+local map = vim.api.nvim_set_keymap
+
+ufo.setup {
+    open_fold_hl_timeout = 0, -- disable blinky thingy when opening fold
+    provider_selector = function(_, ft, _)
+        if ts_parsers.has_parser(ft) then
+            return { "lsp", "treesitter" }
+        else
+            return { "lsp", "indent" }
+        end
+    end,
+}
+
+vim.o.foldcolumn = "1"
+-- https://github.com/neovim/neovim/pull/17446
+vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
+vim.o.foldlevel = 256
+vim.o.foldlevelstart = 256
+vim.o.foldenable = true
+
+local map_opts = {
+    noremap = true,
+    silent = true,
+}
+
+map("n", "t", "za", map_opts) -- toggle fold
+map("n", "zO", [[<cmd>lua require("ufo").openAllFolds()<CR>]], map_opts)
+map("n", "zC", [[<cmd>lua require("ufo").closeAllFolds()<CR>]], map_opts)

.config/nvim/lua/plugins.lua

@@ -164,5 +164,12 @@ return require("packer").startup(function(use)
 
     use "mfussenegger/nvim-jdtls"
 
+    use {
+        "kevinhwang91/nvim-ufo",
+        requires = "kevinhwang91/promise-async",
+        after = "nvim-lspconfig",
+        config = pconf "nvim_ufo",
+    }
+
     cmp_plugins(use)
 end)