bug that delete the newest backups has been fixed

Author: AlexAkulov

utils.go

@@ -130,7 +130,7 @@ func copyFile(srcFile string, dstFile string) error {
 func GetBackupsToDelete(backups []Backup, keep int) []Backup {
 	if len(backups) > keep {
 		sort.SliceStable(backups, func(i, j int) bool {
-			return backups[i].Date.Before(backups[j].Date)
+			return backups[i].Date.After(backups[j].Date)
 		})
 		return backups[keep:]
 	}

utils_test.go

@@ -19,14 +19,14 @@ func timeParse(s string) time.Time {
 func TestGetBackupsToDelete(t *testing.T) {
 	testData := []Backup{
 		Backup{Name: "three", Date: timeParse("2019-03-28T19-50-12")},
+		Backup{Name: "one", Date: timeParse("2019-01-28T19-50-12")},
 		Backup{Name: "five", Date: timeParse("2019-05-28T19-50-12")},
 		Backup{Name: "two", Date: timeParse("2019-02-28T19-50-12")},
-		Backup{Name: "one", Date: timeParse("2019-01-28T19-50-12")},
 		Backup{Name: "four", Date: timeParse("2019-04-28T19-50-12")},
 	}
 	expectedData := []Backup{
-		Backup{Name: "four", Date: timeParse("2019-04-28T19-50-12")},
-		Backup{Name: "five", Date: timeParse("2019-05-28T19-50-12")},
+		Backup{Name: "two", Date: timeParse("2019-02-28T19-50-12")},
+		Backup{Name: "one", Date: timeParse("2019-01-28T19-50-12")},
 	}
 	assert.Equal(t, expectedData, GetBackupsToDelete(testData, 3))
 	assert.Equal(t, []Backup{}, GetBackupsToDelete([]Backup{testData[0]}, 3))