Refactor integration tests infrastructure (#37462)

Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

tests/test_utils.go

@@ -6,7 +6,6 @@ package tests
 import (
 	"database/sql"
 	"fmt"
-	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -25,17 +24,14 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func InitTest() error {
+func InitIntegrationTest() error {
 	testlogger.Init()
 
-	if os.Getenv("GITEA_TEST_CONF") == "" {
-		// By default, use sqlite.ini for testing, then IDE like GoLand can start the test process with debugger.
-		// It's easier for developers to debug bugs step by step with a debugger.
-		// Notice: when doing "ssh push", Gitea executes sub processes, debugger won't work for the sub processes.
-		giteaConf := "tests/sqlite.ini"
-		_ = os.Setenv("GITEA_TEST_CONF", giteaConf)
-		_, _ = fmt.Fprintf(os.Stderr, "Environment variable GITEA_TEST_CONF not set - defaulting to %s\n", giteaConf)
+	err := setting.PrepareIntegrationTestConfig()
+	if err != nil {
+		return err
 	}
+
 	setting.SetupGiteaTestEnv()
 	setting.Repository.DefaultBranch = "master" // many test code still assume that default branch is called "master"
 
@@ -132,6 +128,9 @@ func InitTest() error {
 				return err
 			}
 		}
+	case setting.Database.Type.IsSQLite3():
+	default:
+		return fmt.Errorf("unsupported database type: %s", setting.Database.Type)
 	}
 
 	routers.InitWebInstalled(graceful.GetManager().HammerContext())