You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: update-notifier_test.go
    path of file: ./repos/minio/cmd
    
    the code of the file until where you have to start completion: // Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package cmd

import (
	"fmt"
	"strings"
	"testing"
	"time"

	"github.com/minio/minio/internal/color"
)

// Tests update notifier string builder.
func TestPrepareUpdateMessage(t *testing.T) {
	testCases := []struct {
		older time.Duration
		dlURL string

		expectedSubStr string
	}{
		// Testcase index 0
		{72 * time.Hour, "my_download_url", "3 days before the latest release"},
		{3 * time.Hour, "https://my_download_url_is_huge/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "3 hours before the latest release"},
		{-72 * time.Hour, "another_update_url", ""},
		{0, "another_update_url", ""},
		{time.Hour, "", ""},
		{0 * time.Second, "my_download_url", "now"},
		{1 * time.Second, "my_download_url", "1 seco
    
func TestPrepareUpdateMessage(t *testing.T) {
	testCases := []struct {
		older time.Duration
		dlURL string

		expectedSubStr string
	}{
		// Testcase index 0
		{72 * time.Hour, "my_download_url", "3 days before the latest release"},
		{3 * time.Hour, "https://my_download_url_is_huge/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "3 hours before the latest release"},
		{-72 * time.Hour, "another_update_url", ""},
		{0, "another_update_url", ""},
		{time.Hour, "", ""},
		{0 * time.Second, "my_download_url", "now"},
		{1 * time.Second, "my_download_url", "1 second before the latest release"},
		{37 * time.Second, "my_download_url", "37 seconds before the latest release"},
		{60 * time.Second, "my_download_url", "1 minute before the latest release"},
		{61 * time.Second, "my_download_url", "1 minute before the latest release"},

		// Testcase index 10
		{37 * time.Minute, "my_download_url", "37 minutes before the latest release"},
		{1 * time.Hour, "my_download_url", "1 hour before the latest release"},
		{61 * time.Minute, "my_download_url", "1 hour before the latest release"},
		{122 * time.Minute, "my_download_url", "2 hours before the latest release"},
		{24 * time.Hour, "my_download_url", "1 day before the latest release"},
		{25 * time.Hour, "my_download_url", "1 day before the latest release"},
		{49 * time.Hour, "my_download_url", "2 days before the latest release"},
		{7 * 24 * time.Hour, "my_download_url", "1 week before the latest release"},
		{8 * 24 * time.Hour, "my_download_url", "1 week before the latest release"},
		{15 * 24 * time.Hour, "my_download_url", "2 weeks before the latest release"},

		// Testcase index 20
		{30 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{31 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{61 * 24 * time.Hour, "my_download_url", "2 months before the latest release"},
		{360 * 24 * time.Hour, "my_download_url", "1 year before the latest release"},
		{361 * 24 * time.Hour, "my_download_url", "1 year before the latest release"},
		{2 * 365 * 24 * time.Hour, "my_download_url", "2 years before the latest release"},
	}

	plainMsg := "You are running an older version of MinIO released"

	for i, testCase := range testCases {
		output := prepareUpdateMessage(testCase.dlURL, testCase.older)
		line1 := fmt.Sprintf("%s %s", plainMsg, color.YellowBold(testCase.expectedSubStr))
		line2 := fmt.Sprintf("Update: %s", color.CyanBold(testCase.dlURL))
		// Uncomment below to see message appearance:
		// fmt.Println(output)
		switch {
		case testCase.dlURL == "" && output != "":
			t.Errorf("Testcase %d: no newer release available but got an update message: %s", i+1, output)
		case output == "" && testCase.dlURL != "" && testCase.older > 0:
			t.Errorf("Testcase %d: newer release is available but got empty update message!", i+1)
		case output == "" && (testCase.dlURL == "" || testCase.older <= 0):
			// Valid no update message case. No further
			// validation needed.
			continue
		case !strings.Contains(output, line1):
			t.Errorf("Testcase %d: output '%s' did not contain line 1: '%s'", i+1, output, line1)
		case !strings.Contains(output, line2):
			t.Errorf("Testcase %d: output '%s' did not contain line 2: '%s'", i+1, output, line2)
		}
	}
}