additional tests for optional selectors

pkg/policy/literal/literal.go

@@ -2,6 +2,8 @@
 package literal
 
 import (
+	"fmt"
+
 	"github.com/ipfs/go-cid"
 	"github.com/ipld/go-ipld-prime"
 	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
@@ -24,3 +26,58 @@ func Null() ipld.Node {
 	nb.AssignNull()
 	return nb.Build()
 }
+
+// Map creates an IPLD node from a map[string]interface{}
+func Map(v interface{}) (ipld.Node, error) {
+	m, ok := v.(map[string]interface{})
+	if !ok {
+		return nil, fmt.Errorf("expected map[string]interface{}, got %T", v)
+	}
+
+	nb := basicnode.Prototype.Map.NewBuilder()
+	ma, err := nb.BeginMap(int64(len(m)))
+	if err != nil {
+		return nil, err
+	}
+
+	for k, v := range m {
+		if err := ma.AssembleKey().AssignString(k); err != nil {
+			return nil, err
+		}
+
+		switch x := v.(type) {
+		case string:
+			if err := ma.AssembleValue().AssignString(x); err != nil {
+				return nil, err
+			}
+		case []interface{}:
+			lb := basicnode.Prototype.List.NewBuilder()
+			la, err := lb.BeginList(int64(len(x)))
+			if err != nil {
+				return nil, err
+			}
+			if err := la.Finish(); err != nil {
+				return nil, err
+			}
+			if err := ma.AssembleValue().AssignNode(lb.Build()); err != nil {
+				return nil, err
+			}
+		case map[string]interface{}:
+			nestedNode, err := Map(x) // recursive call for nested maps
+			if err != nil {
+				return nil, err
+			}
+			if err := ma.AssembleValue().AssignNode(nestedNode); err != nil {
+				return nil, err
+			}
+		default:
+			return nil, fmt.Errorf("unsupported value type: %T", v)
+		}
+	}
+
+	if err := ma.Finish(); err != nil {
+		return nil, err
+	}
+
+	return nb.Build(), nil
+}