Marshal nested object does not work

[SkYNewZ]

In a third party library that uses this library, I have an error because marshaling a nested object does not work.

So I take the opportunity to post an issue here as well.
You can see an example test file which demonstrate this issue.

main.go

// main.go
package main

import (
	"bytes"

	"github.com/google/jsonapi"
)

// Nested describes a nested object
type Nested struct {
	Name *string `jsonapi:"attr,name"`
}

// Object is the main example object
type Object struct {
	Type         string  `jsonapi:"primary,object"`
	Color        *string `jsonapi:"attr,color"`
	Enable       *bool   `jsonapi:"attr,enable"`
	NestedObject *Nested `jsonapi:"attr,nested-object"`
}

func MarshalNestedObject() (string, error) {
	n := new(Nested)
	n.Name = toStringPtr("foo")

	var b bytes.Buffer
	err := jsonapi.MarshalPayload(&b, n)
	return b.String(), err
}

func MarshalObject() (string, error) {
	n := new(Nested)
	n.Name = toStringPtr("foo")

	o := &Object{
		Color:        toStringPtr("blue"),
		Enable:       toBoolPtr(true),
		NestedObject: n,
	}

	var b bytes.Buffer
	err := jsonapi.MarshalPayload(&b, o)
	return b.String(), err
}

func toStringPtr(in string) (out *string) {
	out = &in
	return
}

func toBoolPtr(in bool) (out *bool) {
	out = &in
	return
}

main_test.go

// main_test.go
package main

import (
	"reflect"
	"testing"
)

func TestMarshalNestedObject(t *testing.T) {
	tests := []struct {
		name    string
		want    string
		wantErr bool
	}{
		{
			name: "expected",
			want: `{"data":{"type":"","attributes":{"name":"foo"}}}
`,
			wantErr: false,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := MarshalNestedObject()
			if (err != nil) != tt.wantErr {
				t.Errorf("MarshalNestedObject() error = %v, wantErr %v", err, tt.wantErr)
				return
			}
			if !reflect.DeepEqual(got, tt.want) {
				t.Errorf("MarshalNestedObject() got = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestMarshalObject(t *testing.T) {
	tests := []struct {
		name    string
		want    string
		wantErr bool
	}{
		{
			name: "expected",
			want: `{"data":{"type":"object","attributes":{"color":"blue","enable":true,"nested-object":{"name":"foo"}}}}
`,
			wantErr: false,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := MarshalObject()
			if (err != nil) != tt.wantErr {
				t.Errorf("MarshalObject() error = %v, wantErr %v", err, tt.wantErr)
				return
			}

			if !reflect.DeepEqual(got, tt.want) {
				t.Errorf("MarshalObject() got = %v, want %v", got, tt.want)
			}
		})
	}
}