Decouple unit test code from business code (#17623)

models/db/paginator/main_test.go

@@ -0,0 +1,16 @@
+// 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 paginator
+
+import (
+	"path/filepath"
+	"testing"
+
+	"code.gitea.io/gitea/models/unittest"
+)
+
+func TestMain(m *testing.M) {
+	unittest.MainTest(m, filepath.Join("..", "..", ".."))
+}

models/db/paginator/paginator.go

@@ -0,0 +1,8 @@
+// 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 paginator
+
+// dummy only. in the future, the models/db/list_options.go should be moved here to decouple from db package
+// otherwise the unit test will cause cycle import

models/db/paginator/paginator_test.go

@@ -0,0 +1,63 @@
+// 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 paginator
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPaginator(t *testing.T) {
+	cases := []struct {
+		db.Paginator
+		Skip  int
+		Take  int
+		Start int
+		End   int
+	}{
+		{
+			Paginator: &db.ListOptions{Page: -1, PageSize: -1},
+			Skip:      0,
+			Take:      setting.API.DefaultPagingNum,
+			Start:     0,
+			End:       setting.API.DefaultPagingNum,
+		},
+		{
+			Paginator: &db.ListOptions{Page: 2, PageSize: 10},
+			Skip:      10,
+			Take:      10,
+			Start:     10,
+			End:       20,
+		},
+		{
+			Paginator: db.NewAbsoluteListOptions(-1, -1),
+			Skip:      0,
+			Take:      setting.API.DefaultPagingNum,
+			Start:     0,
+			End:       setting.API.DefaultPagingNum,
+		},
+		{
+			Paginator: db.NewAbsoluteListOptions(2, 10),
+			Skip:      2,
+			Take:      10,
+			Start:     2,
+			End:       12,
+		},
+	}
+
+	for _, c := range cases {
+		skip, take := c.Paginator.GetSkipTake()
+		start, end := c.Paginator.GetStartEnd()
+
+		assert.Equal(t, c.Skip, skip)
+		assert.Equal(t, c.Take, take)
+		assert.Equal(t, c.Start, start)
+		assert.Equal(t, c.End, end)
+	}
+}