feat: add UpdatePolicy(#36)

adapter.go

@@ -455,3 +455,10 @@ func (a *Adapter) filterQuery(session *xorm.Session, filter Filter) *xorm.Sessio
 
 	return session
 }
+
+// UpdatePolicy update oldRule to newPolicy permanently
+func (a *Adapter) UpdatePolicy(sec string, ptype string, oldRule, newPolicy []string) error {
+	oRule := a.genPolicyLine(ptype, oldRule)
+	_, err := a.engine.Update(a.genPolicyLine(ptype, newPolicy), oRule)
+	return err
+}

adapter_test.go

@@ -267,6 +267,34 @@ func testAddPolicies(t *testing.T, driverName string, dataSourceName string, dbS
 	testGetPolicy(t, e, [][]string{{"max", "data2", "read"}, {"max", "data1", "write"}})
 }
 
+func testUpdatePolicies(t *testing.T, driverName string, dataSourceName string, dbSpecified ...bool) {
+	// Initialize some policy in DB.
+	initPolicy(t, driverName, dataSourceName, dbSpecified...)
+	// Note: you don't need to look at the above code
+	// if you already have a working DB with policy inside.
+
+	// Now the DB has policy, so we can provide a normal use case.
+	// Create an adapter and an enforcer.
+	// NewEnforcer() will load the policy automatically.
+	a, _ := NewAdapter(driverName, dataSourceName, dbSpecified...)
+	e, _ := casbin.NewEnforcer("examples/rbac_model.conf")
+
+	// Now set the adapter
+	e.SetAdapter(a)
+
+	var err error
+	logErr := func(action string) {
+		if err != nil {
+			t.Fatalf("test action[%s] failed, err: %v", action, err)
+		}
+	}
+
+	err = a.UpdatePolicy("p", "p", []string{"bob", "data2", "write"}, []string{"alice", "data2", "write"})
+	logErr("UpdatePolicy")
+
+	testGetPolicy(t, e, [][]string{{"alice", "data1", "read"}, {"alice", "data2", "write"}, {"data2_admin", "data2", "read"}, {"data2_admin", "data2", "write"}})
+}
+
 func TestAdapters(t *testing.T) {
 	// You can also use the following way to use an existing DB "abc":
 	// testSaveLoad(t, "mysql", "root:@tcp(127.0.0.1:3306)/abc", true)
@@ -284,4 +312,7 @@ func TestAdapters(t *testing.T) {
 
 	testRemovePolicies(t, "mysql", "root:@tcp(127.0.0.1:3306)/")
 	testRemovePolicies(t, "postgres", "user=postgres host=127.0.0.1 port=5432 sslmode=disable")
+
+	testUpdatePolicies(t, "mysql", "root:@tcp(127.0.0.1:3306)/")
+	testUpdatePolicies(t, "postgres", "user=postgres host=127.0.0.1 port=5432 sslmode=disable")
 }