Add Lua configuration support (#2845)

* lua opt trial

* go mod tidy

pkg/settings/lua/lua_test.go

@@ -0,0 +1,83 @@
+package lua
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type testConfig struct {
+	BuildDir      string `json:"buildDir" lua:"build_dir"`
+	RequestSplitN int    `json:"requestsplitn" lua:"request_split_n"`
+	Devel         bool   `json:"devel" lua:"devel"`
+	AnswerClean   string `json:"answerclean"`
+	Ignored       string `json:"-" lua:"-"`
+}
+
+func TestApply(t *testing.T) {
+	e := New()
+	defer e.Close()
+
+	require.NoError(t, e.L.DoString(`
+		yay.opt.build_dir = "/tmp/yay"
+		yay.opt.request_split_n = 200
+		yay.opt.devel = true
+	`))
+
+	cfg := &testConfig{}
+	unknown, errs := e.Apply(cfg)
+
+	assert.Empty(t, unknown)
+	assert.Empty(t, errs)
+	assert.Equal(t, "/tmp/yay", cfg.BuildDir)
+	assert.Equal(t, 200, cfg.RequestSplitN)
+	assert.True(t, cfg.Devel)
+}
+
+func TestApplyUnknownAndTypeMismatch(t *testing.T) {
+	e := New()
+	defer e.Close()
+
+	require.NoError(t, e.L.DoString(`
+		yay.opt.does_not_exist = "x"
+		yay.opt.buildDir = "/tmp/nope"
+		yay.opt.requestsplitn = 200
+		yay.opt.Devel = true
+		yay.opt.devel = "not a bool"
+		yay.opt.build_dir = "/tmp/ok"
+	`))
+
+	cfg := &testConfig{}
+	unknown, errs := e.Apply(cfg)
+
+	assert.ElementsMatch(t, []string{"does_not_exist", "buildDir", "requestsplitn", "Devel"}, unknown)
+	assert.Len(t, errs, 1)
+	assert.Zero(t, cfg.RequestSplitN)
+	assert.False(t, cfg.Devel)
+	assert.Equal(t, "/tmp/ok", cfg.BuildDir)
+}
+
+func TestApplyIgnoresAnswerOptionsWithoutLuaTags(t *testing.T) {
+	e := New()
+	defer e.Close()
+
+	require.NoError(t, e.L.DoString(`
+		yay.opt.answer_clean = "All"
+	`))
+
+	cfg := &testConfig{}
+	unknown, errs := e.Apply(cfg)
+
+	assert.Equal(t, []string{"answer_clean"}, unknown)
+	assert.Empty(t, errs)
+	assert.Empty(t, cfg.AnswerClean)
+}
+
+func TestApplyRejectsNonPointer(t *testing.T) {
+	e := New()
+	defer e.Close()
+
+	_, errs := e.Apply(testConfig{})
+	assert.Len(t, errs, 1)
+}