From e747e612d3da06391a90ef6f47de77351395a74b Mon Sep 17 00:00:00 2001
From: Larry Morales Jordan <larrymoralesjordan@gmail.com>
Date: Fri, 8 May 2020 08:46:17 -0500
Subject: [PATCH] Fix belongs_to tag value to support underscored. (#546)

* Reset to development

* Fix belongs_to tag value to support underscored, also support pointer fields for belongs_to

* add break clause when finding a match
---
 associations/belongs_to_association.go | 18 +++++++++++++++++-
 executors_test.go                      |  4 ++--
 pop_test.go                            |  2 +-
 preload_associations.go                | 20 ++++++++++++++------
 4 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/associations/belongs_to_association.go b/associations/belongs_to_association.go
index 2d70667c..a28e5d0a 100644
--- a/associations/belongs_to_association.go
+++ b/associations/belongs_to_association.go
@@ -31,7 +31,23 @@ func belongsToAssociationBuilder(p associationParams) (Association, error) {
 	ownerVal := p.modelValue.FieldByName(p.field.Name)
 	tags := p.popTags
 	primaryIDField := defaults.String(tags.Find("primary_id").Value, "ID")
-	ownerIDField := defaults.String(tags.Find("fk_id").Value, fmt.Sprintf("%s%s", p.field.Name, "ID"))
+	ownerIDField := fmt.Sprintf("%s%s", p.field.Name, "ID")
+
+	if tags.Find("fk_id").Value != "" {
+		dbTag := tags.Find("fk_id").Value
+		if _, found := p.modelType.FieldByName(dbTag); !found {
+			t := p.modelValue.Type()
+			for i := 0; i < t.NumField(); i++ {
+				f := t.Field(i)
+				if f.Tag.Get("db") == dbTag {
+					ownerIDField = f.Name
+					break
+				}
+			}
+		} else {
+			ownerIDField = dbTag
+		}
+	}
 
 	// belongs_to requires an holding field for the foreign model ID.
 	if _, found := p.modelType.FieldByName(ownerIDField); !found {
diff --git a/executors_test.go b/executors_test.go
index 5af9304b..8b263c72 100644
--- a/executors_test.go
+++ b/executors_test.go
@@ -972,7 +972,7 @@ func Test_Eager_Create_Belongs_To(t *testing.T) {
 
 		car := Taxi{
 			Model: "Fancy car",
-			Driver: User{
+			Driver: &User{
 				Name: nulls.NewString("Larry 2"),
 			},
 		}
@@ -1101,7 +1101,7 @@ func Test_Flat_Create_Belongs_To(t *testing.T) {
 
 		car := Taxi{
 			Model:  "Fancy car",
-			Driver: user,
+			Driver: &user,
 		}
 
 		err = tx.Create(&car)
diff --git a/pop_test.go b/pop_test.go
index 6dd812af..20e4eda5 100644
--- a/pop_test.go
+++ b/pop_test.go
@@ -124,7 +124,7 @@ type Taxi struct {
 	ID        int       `db:"id"`
 	Model     string    `db:"model"`
 	UserID    nulls.Int `db:"user_id"`
-	Driver    User      `belongs_to:"user" fk_id:"UserID"`
+	Driver    *User     `belongs_to:"user" fk_id:"user_id"`
 	CreatedAt time.Time `db:"created_at"`
 	UpdatedAt time.Time `db:"updated_at"`
 }
diff --git a/preload_associations.go b/preload_associations.go
index 99236f2b..5d3be99a 100644
--- a/preload_associations.go
+++ b/preload_associations.go
@@ -270,11 +270,15 @@ func preloadHasMany(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaInf
 			asocValue := slice.Elem().Index(i)
 			if mmi.mapper.FieldByName(mvalue, "ID").Interface() == mmi.mapper.FieldByName(asocValue, foreignField.Path).Interface() ||
 				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, "ID"), mmi.mapper.FieldByName(asocValue, foreignField.Path)) {
-				if modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array {
+
+				switch {
+				case modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array:
 					modelAssociationField.Set(reflect.Append(modelAssociationField, asocValue))
-					continue
+				case modelAssociationField.Kind() == reflect.Ptr:
+					modelAssociationField.Elem().Set(reflect.Append(modelAssociationField.Elem(), asocValue))
+				default:
+					modelAssociationField.Set(asocValue)
 				}
-				modelAssociationField.Set(asocValue)
 			}
 		}
 	})
@@ -380,11 +384,15 @@ func preloadBelongsTo(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaI
 			asocValue := slice.Elem().Index(i)
 			if mmi.mapper.FieldByName(mvalue, fi.Path).Interface() == mmi.mapper.FieldByName(asocValue, "ID").Interface() ||
 				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, fi.Path), mmi.mapper.FieldByName(asocValue, "ID")) {
-				if modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array {
+
+				switch {
+				case modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array:
 					modelAssociationField.Set(reflect.Append(modelAssociationField, asocValue))
-					continue
+				case modelAssociationField.Kind() == reflect.Ptr:
+					modelAssociationField.Elem().Set(asocValue)
+				default:
+					modelAssociationField.Set(asocValue)
 				}
-				modelAssociationField.Set(asocValue)
 			}
 		}
 	})