Split migrations folder (#21549)

There are too many files in `models/migrations` folder so that I split
them into sub folders.

models/migrations/v1_16/v189_test.go

@@ -0,0 +1,83 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package v1_16 //nolint
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/modules/json"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// LoginSource represents an external way for authorizing users.
+type LoginSourceOriginalV189 struct {
+	ID        int64 `xorm:"pk autoincr"`
+	Type      int
+	IsActived bool   `xorm:"INDEX NOT NULL DEFAULT false"`
+	Cfg       string `xorm:"TEXT"`
+	Expected  string `xorm:"TEXT"`
+}
+
+func (ls *LoginSourceOriginalV189) TableName() string {
+	return "login_source"
+}
+
+func Test_UnwrapLDAPSourceCfg(t *testing.T) {
+	// Prepare and load the testing database
+	x, deferable := base.PrepareTestEnv(t, 0, new(LoginSourceOriginalV189))
+	if x == nil || t.Failed() {
+		defer deferable()
+		return
+	}
+	defer deferable()
+
+	// LoginSource represents an external way for authorizing users.
+	type LoginSource struct {
+		ID       int64 `xorm:"pk autoincr"`
+		Type     int
+		IsActive bool   `xorm:"INDEX NOT NULL DEFAULT false"`
+		Cfg      string `xorm:"TEXT"`
+		Expected string `xorm:"TEXT"`
+	}
+
+	// Run the migration
+	if err := UnwrapLDAPSourceCfg(x); err != nil {
+		assert.NoError(t, err)
+		return
+	}
+
+	const batchSize = 100
+	for start := 0; ; start += batchSize {
+		sources := make([]*LoginSource, 0, batchSize)
+		if err := x.Table("login_source").Limit(batchSize, start).Find(&sources); err != nil {
+			assert.NoError(t, err)
+			return
+		}
+
+		if len(sources) == 0 {
+			break
+		}
+
+		for _, source := range sources {
+			converted := map[string]interface{}{}
+			expected := map[string]interface{}{}
+
+			if err := json.Unmarshal([]byte(source.Cfg), &converted); err != nil {
+				assert.NoError(t, err)
+				return
+			}
+
+			if err := json.Unmarshal([]byte(source.Expected), &expected); err != nil {
+				assert.NoError(t, err)
+				return
+			}
+
+			assert.EqualValues(t, expected, converted, "UnwrapLDAPSourceCfg failed for %d", source.ID)
+			assert.EqualValues(t, source.ID%2 == 0, source.IsActive, "UnwrapLDAPSourceCfg failed for %d", source.ID)
+		}
+	}
+}