refactor(test): cleanup test utilities (#2132)

tests/specs/plugins_load_spec.lua

@@ -0,0 +1,35 @@
+local a = require "plenary.async_lib.tests"
+
+a.describe("plugin-loader", function()
+  local plugins = require "lvim.plugins"
+  local loader = require "lvim.plugin-loader"
+
+  a.it("should be able to load default packages without errors", function()
+    loader:load { plugins, lvim.plugins }
+
+    -- TODO: maybe there's a way to avoid hard-coding the names of the modules?
+    local startup_plugins = {
+      "packer",
+    }
+
+    for _, plugin in ipairs(startup_plugins) do
+      assert.truthy(package.loaded[plugin])
+    end
+  end)
+
+  a.it("should be able to load lsp packages without errors", function()
+    loader:load { plugins, lvim.plugins }
+
+    require("lvim.lsp").setup()
+
+    local lsp_packages = {
+      "lspconfig",
+      "nlspsettings",
+      "null-ls",
+    }
+
+    for _, plugin in ipairs(lsp_packages) do
+      assert.truthy(package.loaded[plugin])
+    end
+  end)
+end)