Refactor StringsToInt64s (#29967)

And close #27176

modules/base/tool.go

@@ -150,13 +150,16 @@ func TruncateString(str string, limit int) string {
 
 // StringsToInt64s converts a slice of string to a slice of int64.
 func StringsToInt64s(strs []string) ([]int64, error) {
-	ints := make([]int64, len(strs))
-	for i := range strs {
-		n, err := strconv.ParseInt(strs[i], 10, 64)
+	if strs == nil {
+		return nil, nil
+	}
+	ints := make([]int64, 0, len(strs))
+	for _, s := range strs {
+		n, err := strconv.ParseInt(s, 10, 64)
 		if err != nil {
-			return ints, err
+			return nil, err
 		}
-		ints[i] = n
+		ints = append(ints, n)
 	}
 	return ints, nil
 }

modules/base/tool_test.go

@@ -138,12 +138,13 @@ func TestStringsToInt64s(t *testing.T) {
 		assert.NoError(t, err)
 		assert.Equal(t, expected, result)
 	}
+	testSuccess(nil, nil)
 	testSuccess([]string{}, []int64{})
 	testSuccess([]string{"-1234"}, []int64{-1234})
-	testSuccess([]string{"1", "4", "16", "64", "256"},
-		[]int64{1, 4, 16, 64, 256})
+	testSuccess([]string{"1", "4", "16", "64", "256"}, []int64{1, 4, 16, 64, 256})
 
-	_, err := StringsToInt64s([]string{"-1", "a", "$"})
+	ints, err := StringsToInt64s([]string{"-1", "a"})
+	assert.Len(t, ints, 0)
 	assert.Error(t, err)
 }