Refactor database connection (#37496)

Clean up legacy copied&pasted code, introduce the unique "database
connection" function. Move migration testing helper function
PrepareTestEnv to a separate package.

By the way, remove "shadow connection secrets" tricks: showing
connection string on UI is useless

---------

Co-authored-by: Nicolas <bircni@icloud.com>

models/migrations/v1_26/main_test.go

@@ -6,9 +6,9 @@ package v1_26
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/migrations/migrationtest"
 )
 
 func TestMain(m *testing.M) {
-	base.MainTest(m)
+	migrationtest.MainTest(m)
 }

models/migrations/v1_26/v325_test.go

@@ -6,7 +6,7 @@ package v1_26
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/migrations/migrationtest"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/require"
@@ -38,7 +38,7 @@ func Test_FixMissedRepoIDWhenMigrateAttachments(t *testing.T) {
 	}
 
 	// Prepare and load the testing database
-	x, deferrable := base.PrepareTestEnv(t, 0, new(Attachment), new(Issue), new(Release))
+	x, deferrable := migrationtest.PrepareTestEnv(t, 0, new(Attachment), new(Issue), new(Release))
 	defer deferrable()
 
 	require.NoError(t, FixMissedRepoIDWhenMigrateAttachments(x))

models/migrations/v1_26/v326_test.go

@@ -6,7 +6,7 @@ package v1_26
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/migrations/migrationtest"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 
@@ -57,7 +57,7 @@ func Test_FixCommitStatusTargetURLToUseRunAndJobID(t *testing.T) {
 		TargetURL string
 	}
 
-	x, deferable := base.PrepareTestEnv(t, 0,
+	x, deferable := migrationtest.PrepareTestEnv(t, 0,
 		new(Repository),
 		new(ActionRun),
 		new(ActionRunJob),

models/migrations/v1_26/v327_test.go

@@ -6,7 +6,7 @@ package v1_26
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/migrations/migrationtest"
 
 	"github.com/stretchr/testify/require"
 )
@@ -17,7 +17,7 @@ func Test_AddDisabledToActionRunner(t *testing.T) {
 		Name string
 	}
 
-	x, deferable := base.PrepareTestEnv(t, 0, new(ActionRunner))
+	x, deferable := migrationtest.PrepareTestEnv(t, 0, new(ActionRunner))
 	defer deferable()
 
 	_, err := x.Insert(&ActionRunner{Name: "runner"})

models/migrations/v1_26/v329_test.go

@@ -6,7 +6,7 @@ package v1_26
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models/migrations/base"
+	"code.gitea.io/gitea/models/migrations/migrationtest"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -22,7 +22,7 @@ func (UserBadgeBefore) TableName() string {
 }
 
 func Test_AddUniqueIndexForUserBadge(t *testing.T) {
-	x, deferable := base.PrepareTestEnv(t, 0, new(UserBadgeBefore))
+	x, deferable := migrationtest.PrepareTestEnv(t, 0, new(UserBadgeBefore))
 	defer deferable()
 	if x == nil || t.Failed() {
 		return