Support extending model with anonymous field

constants.go

@@ -10,6 +10,7 @@ const (
 	annotationOmitEmpty = "omitempty"
 	annotationISO8601   = "iso8601"
 	annotationSeperator = ","
+	annotationExtend    = "extend"
 
 	iso8601TimeFormat = "2006-01-02T15:04:05Z"
 

helper.go

@@ -0,0 +1,65 @@
+package jsonapi
+
+import (
+	"reflect"
+	"strings"
+)
+
+type structExtractedField struct {
+	reflect.Value
+	reflect.Kind
+	Annotation string
+	Args       []string
+	IsPtr      bool
+}
+
+func extractFields(model reflect.Value) ([]structExtractedField, error) {
+	modelValue := model.Elem()
+	modelType := model.Type().Elem()
+
+	var fields [](structExtractedField)
+
+	for i := 0; i < modelValue.NumField(); i++ {
+		structField := modelValue.Type().Field(i)
+		fieldValue := modelValue.Field(i)
+		fieldType := modelType.Field(i)
+
+		tag := structField.Tag.Get(annotationJSONAPI)
+		if tag == "" {
+			continue
+		}
+		if tag == annotationExtend && fieldType.Anonymous {
+			extendedFields, er := extractFields(modelValue.Field(i).Addr())
+			if er != nil {
+				return nil, er
+			}
+			fields = append(fields, extendedFields...)
+			continue
+		}
+
+		args := strings.Split(tag, annotationSeperator)
+
+		if len(args) < 1 {
+			return nil, ErrBadJSONAPIStructTag
+		}
+
+		annotation, args := args[0], args[1:]
+
+		if (annotation == annotationClientID && len(args) != 0) ||
+			(annotation != annotationClientID && len(args) < 1) {
+			return nil, ErrBadJSONAPIStructTag
+		}
+
+		// Deal with PTRS
+		kind := fieldValue.Kind()
+		isPtr := fieldValue.Kind() == reflect.Ptr
+		if isPtr {
+			kind = fieldType.Type.Elem().Kind()
+		}
+
+		field := structExtractedField{Value: fieldValue, Kind: kind, Annotation: annotation, Args: args, IsPtr: isPtr}
+		fields = append(fields, field)
+	}
+
+	return fields, nil
+}

helper_test.go

@@ -0,0 +1,187 @@
+package jsonapi
+
+import (
+	"reflect"
+	"testing"
+	"time"
+	"unsafe"
+)
+
+func TestHelper_BadPrimaryAnnotation(t *testing.T) {
+	fields, err := extractFields(reflect.ValueOf(new(BadModel)))
+
+	if fields != nil {
+		t.Fatalf("Was expecting results to be nil")
+	}
+
+	if expected, actual := ErrBadJSONAPIStructTag, err; expected != actual {
+		t.Fatalf("Was expecting error to be `%s`, got `%s`", expected, actual)
+	}
+}
+
+func TestHelper_BadExtendedAnonymousField(t *testing.T) {
+	fields, err := extractFields(reflect.ValueOf(new(WithBadExtendedAnonymousField)))
+
+	if fields != nil {
+		t.Fatalf("Was expecting results to be nil")
+	}
+
+	if expected, actual := ErrBadJSONAPIStructTag, err; expected != actual {
+		t.Fatalf("Was expecting error to be `%s`, got `%s`", expected, actual)
+	}
+}
+
+func TestHelper_returnsProperValue(t *testing.T) {
+	comment := &Comment{}
+	fields, err := extractFields(reflect.ValueOf(comment))
+
+	if err != nil {
+		t.Fatalf("Was expecting error to be nil, got `%s`", err)
+	}
+
+	if expected, actual := 4, len(fields); expected != actual {
+		t.Fatalf("Was expecting fields to have `%d` items, got `%d`", expected, actual)
+	}
+
+	// Check Annotation value
+	if expected, actual := "primary", fields[0].Annotation; expected != actual {
+		t.Fatalf("Was expecting fields[0].Annotation to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := "client-id", fields[1].Annotation; expected != actual {
+		t.Fatalf("Was expecting fields[1].Annotation to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := "attr", fields[2].Annotation; expected != actual {
+		t.Fatalf("Was expecting fields[2].Annotation to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := "attr", fields[3].Annotation; expected != actual {
+		t.Fatalf("Was expecting fields[3].Annotation to be `%s`, got `%s`", expected, actual)
+	}
+
+	// Check Args value
+	if expected, actual := []string{"comments"}, fields[0].Args; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[0].Args to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := []string{}, fields[1].Args; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[1].Args to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := []string{"post_id"}, fields[2].Args; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[2].Args to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := []string{"body"}, fields[3].Args; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[3].Args to be `%s`, got `%s`", expected, actual)
+	}
+
+	// Check IsPtr
+	if expected, actual := false, fields[0].IsPtr; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[0].IsPtr to be `%t`, got `%t`", expected, actual)
+	}
+
+	if expected, actual := false, fields[1].IsPtr; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[1].IsPtr to be `%t`, got `%t`", expected, actual)
+	}
+
+	if expected, actual := false, fields[2].IsPtr; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[2].IsPtr to be `%t`, got `%t`", expected, actual)
+	}
+
+	if expected, actual := false, fields[3].IsPtr; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[3].IsPtr to be `%t`, got `%t`", expected, actual)
+	}
+
+	// Check Value value
+	if uintptr(unsafe.Pointer(&comment.ID)) != fields[0].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[0].Value to point to comment.ID")
+	}
+
+	if uintptr(unsafe.Pointer(&comment.ClientID)) != fields[1].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[1].Value to point to comment.ClientID")
+	}
+
+	if uintptr(unsafe.Pointer(&comment.PostID)) != fields[2].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[2].Value to point to comment.PostID")
+	}
+
+	if uintptr(unsafe.Pointer(&comment.Body)) != fields[3].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[3].Value to point to comment.Body")
+	}
+
+	// Check Kind value
+	if expected, actual := reflect.Int, fields[0].Kind; expected != actual {
+		t.Fatalf("Was expecting fields[0].Kind to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := reflect.String, fields[1].Kind; expected != actual {
+		t.Fatalf("Was expecting fields[1].Kind to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := reflect.Int, fields[2].Kind; expected != actual {
+		t.Fatalf("Was expecting fields[2].Kind to be `%s`, got `%s`", expected, actual)
+	}
+
+	if expected, actual := reflect.String, fields[3].Kind; expected != actual {
+		t.Fatalf("Was expecting fields[3].Kind to be `%s`, got `%s`", expected, actual)
+	}
+
+}
+
+func TestHelper_ignoreFieldWithoutAnnotation(t *testing.T) {
+	book := &Book{
+		ID:          0,
+		Author:      "aren55555",
+		PublishedAt: time.Now().AddDate(0, -1, 0),
+	}
+	fields, err := extractFields(reflect.ValueOf(book))
+	if err != nil {
+		t.Fatalf("Was expecting error to be nil, got `%s`", err)
+	}
+
+	if expected, actual := 7, len(fields); expected != actual {
+		t.Fatalf("Was expecting fields to have `%d` items, got `%d`", expected, actual)
+	}
+}
+
+func TestHelper_WithExtendedAnonymousField(t *testing.T) {
+	model := &WithExtendedAnonymousField{}
+	fields, err := extractFields(reflect.ValueOf(model))
+	if err != nil {
+		t.Fatalf("Was expecting error to be nil, got `%s`", err)
+	}
+
+	if expected, actual := 2, len(fields); expected != actual {
+		t.Fatalf("Was expecting fields to have `%d` items, got `%d`", expected, actual)
+	}
+
+	if uintptr(unsafe.Pointer(&model.CommonField)) != fields[0].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[0].Value to point to comment.CommonField")
+	}
+
+	if uintptr(unsafe.Pointer(&model.ID)) != fields[1].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[1].Value to point to comment.ID")
+	}
+}
+
+func TestHelper_WithPointer(t *testing.T) {
+	model := &WithPointer{}
+	fields, err := extractFields(reflect.ValueOf(model))
+	if err != nil {
+		t.Fatalf("Was expecting error to be nil, got `%s`", err)
+	}
+
+	if expected, actual := 5, len(fields); expected != actual {
+		t.Fatalf("Was expecting fields to have `%d` items, got `%d`", expected, actual)
+	}
+
+	if expected, actual := true, fields[0].IsPtr; !reflect.DeepEqual(expected, actual) {
+		t.Fatalf("Was expecting fields[0].IsPtr to be `%t`, got `%t`", expected, actual)
+	}
+
+	if uintptr(unsafe.Pointer(&model.ID)) != fields[0].Value.UnsafeAddr() {
+		t.Fatalf("Was expecting fields[0].Value to point to comment.ID")
+	}
+}

models_test.go

@@ -25,6 +25,24 @@ type WithPointer struct {
 	FloatVal *float32 `jsonapi:"attr,float-val"`
 }
 
+type base struct {
+	CommonField string `jsonapi:"attr,common_field"`
+}
+
+type WithExtendedAnonymousField struct {
+	base `jsonapi:"extend"`
+	ID   int `jsonapi:"primary,with-extended-anonymous-fields"`
+}
+
+type badBase struct {
+	CommonField string `jsonapi:"attr"`
+}
+
+type WithBadExtendedAnonymousField struct {
+	badBase `jsonapi:"extend"`
+	ID      int `jsonapi:"primary,with-bad-extended-anonymous-fields"`
+}
+
 type Timestamp struct {
 	ID   int        `jsonapi:"primary,timestamps"`
 	Time time.Time  `jsonapi:"attr,timestamp,iso8601"`