tests: check for treesitter langs and mason lsp config

tests/extras/lang_spec.lua

@@ -5,6 +5,7 @@ _G.LazyVim = require("lazyvim.util")
 
 describe("Extra", function()
   local Config = require("lazy.core.config")
+  local Loader = require("lazy.core.loader")
   assert(vim.tbl_count(Config.plugins) > 0, "Lazy not properly setup")
 
   ---@type {modname:string, modpath:string}[]
@@ -18,16 +19,46 @@ describe("Extra", function()
       return name:match("%.lua$")
     end, { limit = math.huge, type = "file", path = "lua/lazyvim/plugins/extras" })
   )
+  local servers = require("mason-lspconfig.mappings.server").package_to_lspconfig
+
+  local tsspec = Plugin.Spec.new({
+    import = "lazyvim.plugins.treesitter",
+  }, { optional = true })
+
+  local tsopts = Plugin.values(tsspec.plugins["nvim-treesitter"], "opts", false)
+
+  local tsensure = tsopts.ensure_installed
+  assert(type(tsensure) == "table", "No ensure_installed in nvim-treesitter spec")
 
   for _, extra in ipairs(extras) do
     it(extra.modname .. " is valid", function()
       local mod = require(extra.modname)
-      local spec = Plugin.Spec.new(mod, { optional = true })
+      local spec = Plugin.Spec.new({
+        { "williamboman/mason.nvim", opts = { ensure_installed = {} } },
+        { "nvim-treesitter/nvim-treesitter", opts = { ensure_installed = {} } },
+        mod,
+      }, { optional = true })
       assert.is_not_nil(mod)
       assert(#spec.notifs == 0, "Invalid spec: " .. vim.inspect(spec.notifs))
 
       if extra.modname:find("%.lang%.") then
         assert(mod.recommended, "`recommended` not set for " .. extra.modname)
+        local mason = spec.plugins["mason.nvim"]
+        local opts = Plugin.values(mason, "opts", false)
+        for _, v in ipairs(opts.ensure_installed) do
+          assert(
+            not servers[v],
+            "LSP server " .. v .. " is installed automatically. Please remove from the mason.nvim spec"
+          )
+        end
+        local ts = spec.plugins["nvim-treesitter"]
+        opts = Plugin.values(mason, "opts", false)
+        for _, v in ipairs(opts.ensure_installed) do
+          assert(
+            not vim.tbl_contains(tsensure, v),
+            "TS lang " .. v .. " is already a default. Please remove from the mason.nvim spec"
+          )
+        end
       end
     end)
   end

tests/init.lua

@@ -19,6 +19,8 @@ local plugins = {
   "LazyVim/starter",
   { "nvim-lua/plenary.nvim" },
   { "folke/lazy.nvim" },
+  "williamboman/mason-lspconfig.nvim",
+  "williamboman/mason.nvim",
 }
 
 local function main()