feat: add ensure_installed to setup table (#637)

README.md

@@ -114,6 +114,7 @@ Example:
 
 ```lua
 require("nvim-lsp-installer").setup({
+    ensure_installed = { "sumneko_lua", "rust_analyzer" },
     ui = {
         icons = {
             server_installed = "✓",
@@ -266,6 +267,8 @@ Illustrations in the logo are derived from [@Kaligule](https://schauderbasis.de/
 
 ```lua
 local DEFAULT_SETTINGS = {
+    -- A list of servers to automatically install. Example: { "rust_analyzer", "sumneko_lua" }
+    ensure_installed = {},
     ui = {
         icons = {
             -- The list icon to use for installed servers.

doc/nvim-lsp-installer.txt

@@ -172,6 +172,8 @@ Example: >
 The following settings are applied by default. >
 
     local DEFAULT_SETTINGS = {
+        -- A list of servers to automatically install. Example: { "rust_analyzer", "sumneko_lua" }
+        ensure_installed = {},
         ui = {
             icons = {
                 -- The list icon to use for installed servers.

lua/nvim-lsp-installer.lua

@@ -14,13 +14,32 @@ local M = {}
 
 M.settings = settings.set
 
+---@param server_identifiers string[]
+local function ensure_installed(server_identifiers)
+    local candidates = {}
+    for _, server_identifier in ipairs(server_identifiers) do
+        local server_name, version = servers.parse_server_identifier(server_identifier)
+        local ok, server = servers.get_server(server_name)
+        if ok and not server:is_installed() then
+            table.insert(candidates, server_name)
+            server:install(version)
+        end
+    end
+    if #candidates > 0 then
+        notify("Installing LSP servers: " .. table.concat(candidates, ", "))
+    end
+end
+
 ---@param config table
 function M.setup(config)
     if config then
         settings.set(config)
     end
     settings.uses_new_setup = true
     require("nvim-lsp-installer.middleware").register_lspconfig_hook()
+    vim.schedule(function()
+        ensure_installed(settings.current.ensure_installed)
+    end)
 end
 
 M.info_window = {

lua/nvim-lsp-installer/settings.lua

@@ -4,6 +4,8 @@ local M = {}
 
 ---@class LspInstallerSettings
 local DEFAULT_SETTINGS = {
+    -- A list of servers to automatically install. Example: { "rust_analyzer", "sumneko_lua" }
+    ensure_installed = {},
     ui = {
         icons = {
             -- The list icon to use for installed servers.