add a ut

dumpling/export/status_test.go

@@ -4,6 +4,7 @@ package export
 
 import (
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 )
@@ -30,3 +31,22 @@ func TestGetParameters(t *testing.T) {
 	require.EqualValues(t, float64(30), mid.FinishedRows)
 	require.EqualValues(t, float64(40), mid.EstimateTotalRows)
 }
+
+func TestSpeedRecorder(t *testing.T) {
+	testCases := []struct {
+		spentTime int64
+		finished  int64
+		expected  int64
+	}{
+		{spentTime: 1, finished: 100, expected: 100},
+		{spentTime: 2, finished: 200, expected: 50},
+		// already finished, will return last speed
+		{spentTime: 3, finished: 200, expected: 50},
+	}
+	speedRecorder := NewSpeedRecorder()
+	for _, tc := range testCases {
+		time.Sleep(time.Duration(tc.spentTime) * time.Second)
+		recentSpeed := speedRecorder.GetSpeed(tc.finished)
+		require.Equal(t, tc.expected, recentSpeed)
+	}
+}