test(master/shardddl): migrate test-infra to testify for master/shardddl pkg

dm/dm/master/shardddl/info_test.go

@@ -14,12 +14,14 @@
 package shardddl
 
 import (
-	. "github.com/pingcap/check"
+	"testing"
+
+	"github.com/stretchr/testify/require"
 
 	"github.com/pingcap/tiflow/dm/pkg/shardddl/pessimism"
 )
 
-func (t *testPessimist) TestInfoSlice(c *C) {
+func TestInfoSlice(t *testing.T) {
 	var (
 		task          = "task"
 		source1       = "mysql-replica-1"
@@ -35,8 +37,8 @@ func (t *testPessimist) TestInfoSlice(c *C) {
 	)
 
 	ifs := pessimismInfoMapToSlice(ifm)
-	c.Assert(ifs, HasLen, 3)
-	c.Assert(ifs[0], DeepEquals, ifm[source1])
-	c.Assert(ifs[1], DeepEquals, ifm[source2])
-	c.Assert(ifs[2], DeepEquals, ifm[source3])
+	require.Len(t, ifs, 3)
+	require.Equal(t, ifm[source1], ifs[0])
+	require.Equal(t, ifm[source2], ifs[1])
+	require.Equal(t, ifm[source3], ifs[2])
 }

dm/dm/master/shardddl/optimist.go

@@ -95,9 +95,8 @@ func (o *Optimist) Start(pCtx context.Context, etcdCli *clientv3.Client) error {
 // Close closes the Optimist instance.
 func (o *Optimist) Close() {
 	o.mu.Lock()
-	defer o.mu.Unlock()
-
 	if o.closed {
+		o.mu.Unlock()
 		return
 	}
 
@@ -106,8 +105,11 @@ func (o *Optimist) Close() {
 		o.cancel = nil
 	}
 
-	o.wg.Wait()
 	o.closed = true // closed now.
+	o.mu.Unlock()
+	// unlock before wg.Wait() to avoid deadlock because other goroutines acquire the lock.
+	// such as https://github.com/pingcap/tiflow/blob/92fc4c4/dm/dm/master/shardddl/optimist.go#L686
+	o.wg.Wait()
 	o.logger.Info("the shard DDL optimist has closed")
 }