feat(encode): accept any input type

pkg/yam/formatted/encoder.go

@@ -166,9 +166,25 @@ func (enc Encoder) UseOptions(options EncodeOptions) (Encoder, error) {
 	return enc, nil
 }
 
-// Encode writes out the formatted YAML from the given yaml.Node to the
-// encoder's io.Writer.
-func (enc Encoder) Encode(node *yaml.Node) error {
+// Encode writes out the formatted YAML from the given value to the encoder's
+// io.Writer.
+func (enc Encoder) Encode(in any) error {
+	var node *yaml.Node
+	switch n := in.(type) {
+	case *yaml.Node:
+		node = n
+
+	case yaml.Node:
+		node = &n
+
+	default:
+		node = new(yaml.Node)
+		err := node.Encode(in)
+		if err != nil {
+			return fmt.Errorf("encoding input to YAML AST node: %w", err)
+		}
+	}
+
 	b, err := enc.marshalRoot(node)
 	if err != nil {
 		return err

pkg/yam/formatted/encoder_test.go

@@ -71,3 +71,94 @@ func TestSortingSequence(t *testing.T) {
 		}
 	}
 }
+
+func TestEncoder_Encode(t *testing.T) {
+	// Sample data as yaml.Node
+	node := &yaml.Node{
+		Kind: yaml.MappingNode,
+		Content: []*yaml.Node{
+			{Kind: yaml.ScalarNode, Value: "update"},
+			{Kind: yaml.MappingNode, Content: []*yaml.Node{
+				{Kind: yaml.ScalarNode, Value: "enabled"},
+				{Kind: yaml.ScalarNode, Value: "true"},
+				{Kind: yaml.ScalarNode, Value: "git"},
+				{Kind: yaml.MappingNode, Style: yaml.FlowStyle},
+				{Kind: yaml.ScalarNode, Value: "schedule"},
+				{Kind: yaml.MappingNode, Content: []*yaml.Node{
+					{Kind: yaml.ScalarNode, Value: "daily"},
+					{Kind: yaml.ScalarNode, Value: "true"},
+					{Kind: yaml.ScalarNode, Value: "reason"},
+					{Kind: yaml.ScalarNode, Value: "upstream does not maintain tags or releases, it uses a branch"},
+				}},
+			}},
+		},
+	}
+
+	// Sample data as user-defined type
+	type Schedule struct {
+		Daily  bool   `yaml:"daily"`
+		Reason string `yaml:"reason"`
+	}
+	type Update struct {
+		Enabled  bool     `yaml:"enabled"`
+		Git      struct{} `yaml:"git"`
+		Schedule Schedule `yaml:"schedule"`
+	}
+	type Document struct {
+		Update Update `yaml:"update"`
+	}
+	document := Document{
+		Update: Update{
+			Enabled: true,
+			Schedule: Schedule{
+				Daily:  true,
+				Reason: "upstream does not maintain tags or releases, it uses a branch",
+			},
+		},
+	}
+
+	// Expected YAML output
+	expectedYAML := `update:
+  enabled: true
+  git: {}
+  schedule:
+    daily: true
+    reason: upstream does not maintain tags or releases, it uses a branch
+`
+
+	t.Run("yaml.Node", func(t *testing.T) {
+		var outNode bytes.Buffer
+		encoderNode := NewEncoder(&outNode)
+		err := encoderNode.Encode(node)
+		require.NoError(t, err)
+
+		checkDiff(t, expectedYAML, outNode.String())
+	})
+
+	t.Run("user-defined type", func(t *testing.T) {
+		// Encode user-defined type
+		var outStruct bytes.Buffer
+		encoderStruct := NewEncoder(&outStruct)
+		err := encoderStruct.Encode(document)
+		require.NoError(t, err)
+
+		checkDiff(t, expectedYAML, outStruct.String())
+	})
+}
+
+func checkDiff(t *testing.T, expected, actual any) {
+	t.Helper()
+
+	if diff := cmp.Diff(expected, actual); diff != "" {
+		t.Errorf(`unexpected document (-want +got):
+%s
+
+full expected:
+
+%s
+
+full actual:
+
+%s`, diff, expected, actual)
+	}
+}