Added support for gorm/v2 (#36)

* Added support for gorm/v2

Signed-off-by: l1ghtman2k <aibek.zhil@gmail.com>

* Add gorm-adapter/v3 to the documentation

Signed-off-by: l1ghtman2k <aibek.zhil@gmail.com>

* Return a modified finalizer

Signed-off-by: l1ghtman2k <aibek.zhil@gmail.com>

README.md

@@ -9,7 +9,7 @@ Gorm Adapter
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/casbin/lobby)
 [![Sourcegraph](https://sourcegraph.com/github.com/casbin/gorm-adapter/-/badge.svg)](https://sourcegraph.com/github.com/casbin/gorm-adapter?badge)
 
-Gorm Adapter is the [Gorm](https://github.com/jinzhu/gorm) adapter for [Casbin](https://github.com/casbin/casbin). With this library, Casbin can load policy from Gorm supported database or save policy to it.
+Gorm Adapter is the [Gorm](https://gorm.io/gorm) adapter for [Casbin](https://github.com/casbin/casbin). With this library, Casbin can load policy from Gorm supported database or save policy to it.
 
 Based on [Officially Supported Databases](http://jinzhu.me/gorm/database.html), The current supported databases are:
 
@@ -31,7 +31,7 @@ package main
 
 import (
 	"github.com/casbin/casbin/v2"
-	gormadapter "github.com/casbin/gorm-adapter/v2"
+	gormadapter "github.com/casbin/gorm-adapter/v3"
 	_ "github.com/go-sql-driver/mysql"
 )
 

adapter.go

@@ -16,13 +16,16 @@ package gormadapter
 
 import (
 	"errors"
-	"runtime"
-	"strings"
-
 	"github.com/casbin/casbin/v2/model"
 	"github.com/casbin/casbin/v2/persist"
-	"github.com/jinzhu/gorm"
 	"github.com/lib/pq"
+	"gorm.io/driver/mysql"
+	"gorm.io/driver/postgres"
+	"gorm.io/driver/sqlite"
+	"gorm.io/driver/sqlserver"
+	"gorm.io/gorm"
+	"runtime"
+	"strings"
 )
 
 var tablePrefix string
@@ -64,7 +67,11 @@ type Adapter struct {
 
 // finalizer is the destructor for Adapter.
 func finalizer(a *Adapter) {
-	err := a.db.Close()
+	sqlDB, err := a.db.DB()
+	if err != nil {
+		panic(err)
+	}
+	err = sqlDB.Close()
 	if err != nil {
 		panic(err)
 	}
@@ -131,74 +138,77 @@ func NewAdapterByDB(db *gorm.DB) (*Adapter, error) {
 	return a, nil
 }
 
-func (a *Adapter) createDatabase() error {
+func openDBConnection(driverName, dataSourceName string) (*gorm.DB, error) {
 	var err error
 	var db *gorm.DB
-	if a.driverName == "postgres" {
-		db, err = gorm.Open(a.driverName, a.dataSourceName+" dbname=postgres")
+	if driverName == "postgres" {
+		db, err = gorm.Open(postgres.Open(dataSourceName+" dbname=postgres"), &gorm.Config{})
+	} else if driverName == "mysql" {
+		db, err = gorm.Open(mysql.Open(dataSourceName), &gorm.Config{})
+	} else if driverName == "sqlite3" {
+		db, err = gorm.Open(sqlite.Open(dataSourceName), &gorm.Config{})
+	} else if driverName == "sqlserver" {
+		db, err = gorm.Open(sqlserver.Open(dataSourceName), &gorm.Config{})
 	} else {
-		db, err = gorm.Open(a.driverName, a.dataSourceName)
+		return nil, errors.New("database dialect is not supported")
 	}
 	if err != nil {
-		return err
+		return nil, err
 	}
+	return db, err
+}
 
+func (a *Adapter) createDatabase() error {
+	var err error
+	db, err := openDBConnection(a.driverName, a.dataSourceName)
+	if err != nil {
+		return err
+	}
 	if a.driverName == "postgres" {
 		if err = db.Exec("CREATE DATABASE casbin").Error; err != nil {
 			// 42P04 is	duplicate_database
 			if err.(*pq.Error).Code == "42P04" {
-				db.Close()
 				return nil
 			}
 		}
 	} else if a.driverName != "sqlite3" {
 		err = db.Exec("CREATE DATABASE IF NOT EXISTS casbin").Error
 	}
 	if err != nil {
-		db.Close()
 		return err
 	}
-
-	return db.Close()
+	return nil
 }
 
 func (a *Adapter) open() error {
 	var err error
 	var db *gorm.DB
 
 	if a.dbSpecified {
-		db, err = gorm.Open(a.driverName, a.dataSourceName)
+		db, err = openDBConnection(a.driverName, a.dataSourceName)
 		if err != nil {
 			return err
 		}
 	} else {
 		if err = a.createDatabase(); err != nil {
 			return err
 		}
-
 		if a.driverName == "postgres" {
-			db, err = gorm.Open(a.driverName, a.dataSourceName+" dbname=casbin")
+			db, err = openDBConnection(a.driverName, a.dataSourceName+" dbname=casbin")
 		} else if a.driverName == "sqlite3" {
-			db, err = gorm.Open(a.driverName, a.dataSourceName)
+			db, err = openDBConnection(a.driverName, a.dataSourceName)
 		} else {
-			db, err = gorm.Open(a.driverName, a.dataSourceName+"casbin")
+			db, err = openDBConnection(a.driverName, a.dataSourceName+"casbin")
 		}
 		if err != nil {
 			return err
 		}
 	}
-
 	a.db = db
-
 	return a.createTable()
 }
 
 func (a *Adapter) close() error {
-	err := a.db.Close()
-	if err != nil {
-		return err
-	}
-
 	a.db = nil
 	return nil
 }
@@ -209,15 +219,15 @@ func (a *Adapter) getTableInstance() *CasbinRule {
 }
 
 func (a *Adapter) createTable() error {
-	if a.db.HasTable(a.getTableInstance()) {
+	if a.db.Migrator().HasTable(a.getTableInstance()) {
 		return nil
 	}
 
-	return a.db.CreateTable(a.getTableInstance()).Error
+	return a.db.Migrator().CreateTable(a.getTableInstance())
 }
 
 func (a *Adapter) dropTable() error {
-	return a.db.DropTable(a.getTableInstance()).Error
+	return a.db.Migrator().DropTable(a.getTableInstance())
 }
 
 func loadPolicyLine(line CasbinRule, model model.Model) {

adapter_test.go

@@ -15,19 +15,18 @@
 package gormadapter
 
 import (
+	"gorm.io/driver/mysql"
+	"gorm.io/driver/postgres"
 	"log"
 	"os"
 	"testing"
 
 	"github.com/casbin/casbin/v2"
 	"github.com/casbin/casbin/v2/util"
 	_ "github.com/go-sql-driver/mysql"
-	"github.com/jinzhu/gorm"
-	_ "github.com/jinzhu/gorm/dialects/mssql"
-	_ "github.com/jinzhu/gorm/dialects/postgres"
-	_ "github.com/jinzhu/gorm/dialects/sqlite"
 	_ "github.com/lib/pq"
 	"github.com/stretchr/testify/assert"
+	"gorm.io/gorm"
 )
 
 func testGetPolicy(t *testing.T, e *casbin.Enforcer, res [][]string) {
@@ -199,7 +198,7 @@ func TestAdapters(t *testing.T) {
 	testAutoSave(t, a)
 	testSaveLoad(t, a)
 
-	db, err := gorm.Open("mysql", "root:@tcp(127.0.0.1:3306)/casbin")
+	db, err := gorm.Open(mysql.Open("root:@tcp(127.0.0.1:3306)/casbin"), &gorm.Config{})
 	if err != nil {
 		panic(err)
 	}
@@ -210,7 +209,7 @@ func TestAdapters(t *testing.T) {
 	a = initAdapterWithGormInstance(t, db)
 	testFilteredPolicy(t, a)
 
-	db, err = gorm.Open("postgres", "user=postgres host=127.0.0.1 port=5432 sslmode=disable dbname=casbin")
+	db, err = gorm.Open(postgres.Open("user=postgres host=127.0.0.1 port=5432 sslmode=disable dbname=casbin"), &gorm.Config{})
 	if err != nil {
 		panic(err)
 	}

go.mod

@@ -1,11 +1,16 @@
-module github.com/casbin/gorm-adapter/v2
+module github.com/casbin/gorm-adapter/v3
 
 go 1.12
 
 require (
 	github.com/casbin/casbin/v2 v2.2.2
-	github.com/go-sql-driver/mysql v1.4.1
-	github.com/jinzhu/gorm v1.9.12
-	github.com/lib/pq v1.1.1
-	github.com/stretchr/testify v1.3.0
+	github.com/go-sql-driver/mysql v1.5.0
+	github.com/lib/pq v1.3.0
+	github.com/mattn/go-sqlite3 v2.0.1+incompatible // indirect
+	github.com/stretchr/testify v1.5.1
+	gorm.io/driver/mysql v0.3.0
+	gorm.io/driver/postgres v0.2.6
+	gorm.io/driver/sqlite v1.0.8
+	gorm.io/driver/sqlserver v0.2.4
+	gorm.io/gorm v0.2.23
 )