at-container-registry/pkg/config/marshal_test.go

package config

import (
	"strings"
	"testing"
	"time"
)

type testConfig struct {
	Name     string        `yaml:"name" comment:"The display name."`
	Port     int           `yaml:"port" comment:"Listen port."`
	Enabled  bool          `yaml:"enabled" comment:"Enable the service."`
	Timeout  time.Duration `yaml:"timeout" comment:"Request timeout."`
	Internal string        `yaml:"-"`
	Nested   testNested    `yaml:"nested" comment:"Nested section."`
}

type testNested struct {
	Endpoint string `yaml:"endpoint" comment:"API endpoint URL."`
	Retries  int    `yaml:"retries" comment:"Number of retries."`
}

func TestMarshalCommentedYAML_CommentsRendered(t *testing.T) {
	cfg := testConfig{
		Name:    "myapp",
		Port:    8080,
		Enabled: true,
		Timeout: 15 * time.Minute,
		Nested: testNested{
			Endpoint: "https://api.example.com",
			Retries:  3,
		},
	}

	out, err := MarshalCommentedYAML("Test Config", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)

	// Title is rendered as head comment
	if !strings.Contains(s, "# Test Config") {
		t.Error("expected title comment in output")
	}

	// Field comments are rendered
	for _, want := range []string{
		"# The display name.",
		"# Listen port.",
		"# Enable the service.",
		"# Request timeout.",
		"# Nested section.",
		"# API endpoint URL.",
		"# Number of retries.",
	} {
		if !strings.Contains(s, want) {
			t.Errorf("expected comment %q in output", want)
		}
	}

	// Field values are rendered
	if !strings.Contains(s, "name: myapp") {
		t.Error("expected name field value")
	}
	if !strings.Contains(s, "port: 8080") {
		t.Error("expected port field value")
	}
	if !strings.Contains(s, "enabled: true") {
		t.Error("expected enabled field value")
	}
}

func TestMarshalCommentedYAML_DurationRendersAsString(t *testing.T) {
	cfg := testConfig{
		Timeout: 15 * time.Minute,
	}

	out, err := MarshalCommentedYAML("", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)
	if !strings.Contains(s, "timeout: 15m0s") {
		t.Errorf("expected duration as string, got:\n%s", s)
	}
}

func TestMarshalCommentedYAML_ZeroDuration(t *testing.T) {
	cfg := testConfig{}

	out, err := MarshalCommentedYAML("", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)
	if !strings.Contains(s, "timeout: 0s") {
		t.Errorf("expected zero duration as '0s', got:\n%s", s)
	}
}

func TestMarshalCommentedYAML_YamlDashExcluded(t *testing.T) {
	cfg := testConfig{
		Internal: "should-not-appear",
	}

	out, err := MarshalCommentedYAML("", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)
	if strings.Contains(s, "should-not-appear") {
		t.Error("yaml:\"-\" field should not appear in output")
	}
	if strings.Contains(s, "internal") {
		t.Error("yaml:\"-\" field key should not appear in output")
	}
}

func TestMarshalCommentedYAML_NestedStructs(t *testing.T) {
	cfg := testConfig{
		Nested: testNested{
			Endpoint: "https://api.example.com",
			Retries:  3,
		},
	}

	out, err := MarshalCommentedYAML("", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)
	if !strings.Contains(s, "endpoint: https://api.example.com") {
		t.Errorf("expected nested endpoint value in output:\n%s", s)
	}
	if !strings.Contains(s, "retries: 3") {
		t.Errorf("expected nested retries value in output:\n%s", s)
	}
}

func TestMarshalCommentedYAML_PointerStruct(t *testing.T) {
	cfg := &testConfig{
		Name: "ptr-test",
		Port: 9090,
	}

	out, err := MarshalCommentedYAML("Pointer Test", cfg)
	if err != nil {
		t.Fatalf("MarshalCommentedYAML() error: %v", err)
	}

	s := string(out)
	if !strings.Contains(s, "name: ptr-test") {
		t.Error("expected name field from pointer struct")
	}
}