feat: expose Resolver.Copy

directive.go

@@ -50,8 +50,17 @@ func ParseDirective(directive string) (*Directive, error) {
 	return NewDirective(name, argv...), nil
 }
 
-func isValidDirectiveName(name string) bool {
-	return reDirectiveName.MatchString(name)
+// Copy creates a copy of the directive. The copy is a deep copy.
+func (d *Directive) Copy() *Directive {
+	return NewDirective(d.Name, d.Argv...)
+}
+
+// String returns the string representation of the directive.
+func (d *Directive) String() string {
+	if len(d.Argv) == 0 {
+		return d.Name
+	}
+	return d.Name + "=" + strings.Join(d.Argv, ",")
 }
 
 // DirectiveExecutor is the interface that wraps the Execute method.
@@ -108,3 +117,7 @@ type DirectiveRuntime struct {
 	// and if in dirA we set a value of "foo" to "bar", then in dirB we can get the value of "foo" as "bar".
 	Context context.Context
 }
+
+func isValidDirectiveName(name string) bool {
+	return reDirectiveName.MatchString(name)
+}

directive_test.go

@@ -66,3 +66,11 @@ func TestParseDirective(t *testing.T) {
 		assert.ErrorIs(t, err, testcase.err)
 	}
 }
+
+func TestDirective_String(t *testing.T) {
+	d := owl.NewDirective("form", "page", "page_index")
+	assert.Equal(t, "form=page,page_index", d.String())
+
+	d = owl.NewDirective("required")
+	assert.Equal(t, "required", d.String())
+}

resolver.go

@@ -43,7 +43,7 @@ func New(structValue interface{}, opts ...Option) (*Resolver, error) {
 	if err != nil {
 		return nil, err
 	}
-	tree = tree.copy()
+	tree = tree.Copy()
 
 	// Apply options, build the context for each resolver.
 	defaultOpts := []Option{WithNamespace(defaultNS)}
@@ -67,15 +67,28 @@ func New(structValue interface{}, opts ...Option) (*Resolver, error) {
 	return tree, nil
 }
 
-func (r *Resolver) copy() *Resolver {
+// Copy returns a copy of the resolver tree. The copy is a deep copy, which
+// means the children are also copied.
+func (r *Resolver) Copy() *Resolver {
 	resolverCopy := new(Resolver)
 	*resolverCopy = *r
-	resolverCopy.Context = context.Background()
 
-	// Copy the children.
+	// Copy index and path.
+	resolverCopy.Index = make([]int, len(r.Index))
+	copy(resolverCopy.Index, r.Index)
+	resolverCopy.Path = make([]string, len(r.Path))
+	copy(resolverCopy.Path, r.Path)
+
+	// Copy the directives.
+	resolverCopy.Directives = make([]*Directive, len(r.Directives))
+	for i, d := range r.Directives {
+		resolverCopy.Directives[i] = d.Copy()
+	}
+
+	// Copy the children and set the parent.
 	resolverCopy.Children = make([]*Resolver, len(r.Children))
 	for i, child := range r.Children {
-		resolverCopy.Children[i] = child.copy()
+		resolverCopy.Children[i] = child.Copy()
 		resolverCopy.Children[i].Parent = resolverCopy
 	}
 	return resolverCopy

resolver_test.go

@@ -182,7 +182,7 @@ func TestNew_SkipFieldsHavingNoDirectives(t *testing.T) {
 				Index:      []int{},
 				LookupPath: "",
 				NumFields:  3,
-				Directives: nil,
+				Directives: []*owl.Directive{},
 				Leaf:       false,
 			},
 			{
@@ -206,7 +206,7 @@ func TestNew_SkipFieldsHavingNoDirectives(t *testing.T) {
 				Index:      []int{3}, // Pagination is the 4th field, Hidden is the 3rd field.
 				LookupPath: "Pagination",
 				NumFields:  2,
-				Directives: nil,
+				Directives: []*owl.Directive{},
 				Leaf:       false,
 			},
 			{