From a19ba3d5307ef7c20bc7f1bb6ee1e554ac346e76 Mon Sep 17 00:00:00 2001
From: John Guo <john@johng.cn>
Date: Tue, 26 Oct 2021 21:57:56 +0800
Subject: [PATCH] add embedded struct fields overwrite feature for package
 internal/structs

---
 internal/structs/structs_field.go             | 42 ++++++++++++++-----
 internal/structs/structs_z_unit_test.go       | 40 +++++++++++++++++-
 util/gvalid/gvalid_validator_rule_required.go |  2 +-
 3 files changed, 71 insertions(+), 13 deletions(-)

diff --git a/internal/structs/structs_field.go b/internal/structs/structs_field.go
index 4b0955b68..518258b00 100644
--- a/internal/structs/structs_field.go
+++ b/internal/structs/structs_field.go
@@ -116,9 +116,6 @@ type FieldsInput struct {
 	// RecursiveOption specifies the way retrieving the fields recursively if the attribute
 	// is an embedded struct. It is RecursiveOptionNone in default.
 	RecursiveOption int
-
-	// fieldFilterMap is used internally for repeated fields filtering.
-	fieldFilterMap map[string]struct{}
 }
 
 type FieldMapInput struct {
@@ -136,19 +133,28 @@ type FieldMapInput struct {
 
 // Fields retrieves and returns the fields of `pointer` as slice.
 func Fields(in FieldsInput) ([]*Field, error) {
-	if in.fieldFilterMap == nil {
-		in.fieldFilterMap = make(map[string]struct{})
-	}
 	var (
-		retrievedFields = make([]*Field, 0)
+		ok                   bool
+		fieldFilterMap       = make(map[string]struct{})
+		retrievedFields      = make([]*Field, 0)
+		currentLevelFieldMap = make(map[string]*Field)
 	)
 	rangeFields, err := getFieldValues(in.Pointer)
 	if err != nil {
 		return nil, err
 	}
+
 	for index := 0; index < len(rangeFields); index++ {
 		field := rangeFields[index]
-		if _, ok := in.fieldFilterMap[field.Name()]; ok {
+		if !field.IsExported() {
+			continue
+		}
+		currentLevelFieldMap[field.Name()] = field
+	}
+
+	for index := 0; index < len(rangeFields); index++ {
+		field := rangeFields[index]
+		if _, ok = fieldFilterMap[field.Name()]; ok {
 			continue
 		}
 		// It only retrieves exported attributes.
@@ -167,18 +173,32 @@ func Fields(in FieldsInput) ([]*Field, error) {
 					structFields, err := Fields(FieldsInput{
 						Pointer:         field.Value,
 						RecursiveOption: in.RecursiveOption,
-						fieldFilterMap:  in.fieldFilterMap,
 					})
 					if err != nil {
 						return nil, err
 					}
-					retrievedFields = append(retrievedFields, structFields...)
+					// The current level fields can overwrite the sub-struct fields with the same name.
+					for i := 0; i < len(structFields); i++ {
+						var (
+							structField = structFields[i]
+							fieldName   = structField.Name()
+						)
+						if _, ok = fieldFilterMap[fieldName]; ok {
+							continue
+						}
+						fieldFilterMap[fieldName] = struct{}{}
+						if v := currentLevelFieldMap[fieldName]; v == nil {
+							retrievedFields = append(retrievedFields, structField)
+						} else {
+							retrievedFields = append(retrievedFields, v)
+						}
+					}
 					continue
 				}
 			}
 			continue
 		}
-		in.fieldFilterMap[field.Name()] = struct{}{}
+		fieldFilterMap[field.Name()] = struct{}{}
 		retrievedFields = append(retrievedFields, field)
 	}
 	return retrievedFields, nil
diff --git a/internal/structs/structs_z_unit_test.go b/internal/structs/structs_z_unit_test.go
index 377f1538b..1668e8b10 100644
--- a/internal/structs/structs_z_unit_test.go
+++ b/internal/structs/structs_z_unit_test.go
@@ -125,7 +125,7 @@ func Test_Fields(t *testing.T) {
 	})
 }
 
-func Test_Fields_WithEmbedded(t *testing.T) {
+func Test_Fields_WithEmbedded1(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
 		type B struct {
 			Name string
@@ -149,6 +149,44 @@ func Test_Fields_WithEmbedded(t *testing.T) {
 	})
 }
 
+func Test_Fields_WithEmbedded2(t *testing.T) {
+	type MetaNode struct {
+		Id          uint   `orm:"id,primary"  description:""`
+		Capacity    string `orm:"capacity"    description:"Capacity string"`
+		Allocatable string `orm:"allocatable" description:"Allocatable string"`
+		Status      string `orm:"status"      description:"Status string"`
+	}
+	type MetaNodeZone struct {
+		Nodes    uint
+		Clusters uint
+		Disk     uint
+		Cpu      uint
+		Memory   uint
+		Zone     string
+	}
+
+	type MetaNodeItem struct {
+		MetaNode
+		Capacity    []MetaNodeZone `dc:"Capacity []MetaNodeZone"`
+		Allocatable []MetaNodeZone `dc:"Allocatable []MetaNodeZone"`
+	}
+
+	gtest.C(t, func(t *gtest.T) {
+		r, err := structs.Fields(structs.FieldsInput{
+			Pointer:         new(MetaNodeItem),
+			RecursiveOption: structs.RecursiveOptionEmbeddedNoTag,
+		})
+		t.AssertNil(err)
+		t.Assert(len(r), 4)
+		t.Assert(r[0].Name(), `Id`)
+		t.Assert(r[1].Name(), `Capacity`)
+		t.Assert(r[1].TagStr(), `dc:"Capacity []MetaNodeZone"`)
+		t.Assert(r[2].Name(), `Allocatable`)
+		t.Assert(r[2].TagStr(), `dc:"Allocatable []MetaNodeZone"`)
+		t.Assert(r[3].Name(), `Status`)
+	})
+}
+
 // Filter repeated fields when there is embedded struct.
 func Test_Fields_WithEmbedded_Filter(t *testing.T) {
 	gtest.C(t, func(t *gtest.T) {
diff --git a/util/gvalid/gvalid_validator_rule_required.go b/util/gvalid/gvalid_validator_rule_required.go
index e50be29e0..14470f96d 100644
--- a/util/gvalid/gvalid_validator_rule_required.go
+++ b/util/gvalid/gvalid_validator_rule_required.go
@@ -116,7 +116,7 @@ func (v *Validator) checkRequired(value interface{}, ruleKey, rulePattern string
 			}
 		}
 
-	// Required if all of given fields are empty.
+	// Required if all given fields are empty.
 	// Example: required-with:id,name
 	case "required-without-all":
 		required = true