demonstrate gorm AfterUpdate hook failure

afterupdate_hook_test.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"fmt"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"gorm.io/gorm"
+	"testing"
+)
+
+type Product6 struct {
+	ID       uint `gorm:"primarykey"`
+	Name     *string
+	UniqueId *uuid.UUID `gorm:"type:varchar(36);unique" json:",omitempty"`
+}
+
+// Hold copy of the values passed to the AfterUpdate() for subsequent check
+var hookName *string
+var hookUuid *uuid.UUID
+
+func (p *Product6) AfterUpdate(*gorm.DB) error {
+
+	hookName = p.Name
+	hookUuid = p.UniqueId
+
+	name := "nil"
+	if p.Name != nil {
+		name = *p.Name
+	}
+	uniqueId := "nil"
+	if p.UniqueId != nil {
+		uniqueId = p.UniqueId.String()
+	}
+	fmt.Printf("After update p.UniqueId %v p.Name %v\n", uniqueId, name)
+	return nil
+}
+
+func StringPtr(s string) *string {
+	return &s
+}
+func UuidPtr(u uuid.UUID) *uuid.UUID {
+	return &u
+}
+
+func TestAfterUpdateHook(t *testing.T) {
+	DB.Migrator().DropTable(&Product6{})
+	DB.Debug().AutoMigrate(&Product6{})
+
+	productName := StringPtr("product name")
+	productUuid := UuidPtr(uuid.MustParse("5f003fc3-f806-42a3-ae4e-4d4335581de0"))
+	p := Product6{Name: productName, UniqueId: productUuid}
+	DB.Model(&Product6{}).Create(&p)
+
+	p.Name = nil
+	p.UniqueId = nil
+	err := DB.Model(&p).Updates(map[string]interface{}{"name": p.Name, "unique_id": p.UniqueId}).Error
+	assert.Nil(t, err)
+	assert.Nil(t, hookName)
+	assert.Nil(t, hookUuid)
+
+	productName = StringPtr("new name")
+	productUuid = UuidPtr(uuid.MustParse("415d9c8a-8742-4fe6-a6cd-8062a121eeb4"))
+	err = DB.Model(&p).Updates(map[string]interface{}{"name": productName, "unique_id": productUuid}).Error
+	assert.Nil(t, err)
+	assert.Equal(t, hookName, productName)
+	assert.Equal(t, hookUuid, productUuid)
+
+	productName = nil
+	productUuid = nil
+	err = DB.Model(&p).Updates(map[string]interface{}{"name": productName, "unique_id": productUuid}).Error
+	assert.Nil(t, err)
+	assert.Nil(t, hookName)
+	assert.Nil(t, hookUuid)
+}

go.mod

@@ -3,30 +3,38 @@ module gorm.io/playground
 go 1.20
 
 require (
-	gorm.io/driver/mysql v1.5.2
-	gorm.io/driver/postgres v1.5.2
-	gorm.io/driver/sqlite v1.5.3
-	gorm.io/driver/sqlserver v1.5.1
+	github.com/google/uuid v1.6.0
+	github.com/stretchr/testify v1.9.0
+	gorm.io/driver/mysql v1.5.7
+	gorm.io/driver/postgres v1.5.9
+	gorm.io/driver/sqlite v1.5.6
+	gorm.io/driver/sqlserver v1.5.3
 	gorm.io/gen v0.3.25
-	gorm.io/gorm v1.25.4
+	gorm.io/gorm v1.25.10
 )
 
 require (
-	github.com/go-sql-driver/mysql v1.7.1 // indirect
+	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/go-sql-driver/mysql v1.8.1 // indirect
 	github.com/golang-sql/civil v0.0.0-20220223132316-b832511892a9 // indirect
 	github.com/golang-sql/sqlexp v0.1.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
-	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
-	github.com/jackc/pgx/v5 v5.4.3 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/pgx/v5 v5.6.0 // indirect
+	github.com/jackc/puddle/v2 v2.2.1 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
-	github.com/mattn/go-sqlite3 v1.14.17 // indirect
-	github.com/microsoft/go-mssqldb v1.5.0 // indirect
-	golang.org/x/crypto v0.14.0 // indirect
-	golang.org/x/mod v0.14.0 // indirect
-	golang.org/x/sys v0.14.0 // indirect
-	golang.org/x/text v0.13.0 // indirect
-	golang.org/x/tools v0.15.0 // indirect
+	github.com/mattn/go-sqlite3 v1.14.22 // indirect
+	github.com/microsoft/go-mssqldb v1.7.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	golang.org/x/crypto v0.24.0 // indirect
+	golang.org/x/mod v0.17.0 // indirect
+	golang.org/x/sync v0.7.0 // indirect
+	golang.org/x/sys v0.21.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
+	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 	gorm.io/datatypes v1.1.1-0.20230130040222-c43177d3cf8c // indirect
 	gorm.io/hints v1.1.0 // indirect
 	gorm.io/plugin/dbresolver v1.5.0 // indirect