server: migrate test-infra to testify for tidb_test.go

server/main_test.go

@@ -21,6 +21,7 @@ import (
 	"testing"
 
 	"github.com/pingcap/tidb/config"
+	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/util/testbridge"
 	"github.com/tikv/client-go/v2/tikv"
@@ -30,12 +31,16 @@ import (
 func TestMain(m *testing.M) {
 	testbridge.WorkaroundGoCheckFlags()
 
+	runInGoTest = true // flag for NewServer to known it is running in test environment
+
 	// AsyncCommit will make DDL wait 2.5s before changing to the next state.
 	// Set schema lease to avoid it from making CI slow.
 	session.SetSchemaLease(0)
 
 	tikv.EnableFailpoints()
 
+	metrics.RegisterMetrics()
+
 	// sanity check: the global config should not be changed by other pkg init function.
 	// see also https://github.com/pingcap/tidb/issues/22162
 	defaultConfig := config.NewConfig()

server/server.go

@@ -32,7 +32,6 @@ package server
 import (
 	"context"
 	"crypto/tls"
-	"flag"
 	"fmt"
 	"math/rand"
 	"net"
@@ -88,7 +87,6 @@ func init() {
 	if err != nil {
 		osVersion = ""
 	}
-	runInGoTest = flag.Lookup("test.v") != nil || flag.Lookup("check.v") != nil
 }
 
 var (