// 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 (	"context"	"os"	"path/filepath"	"testing") // TestFSFormatFS - tests initFormatFS, formatMetaGetFormatBackendFS, formatFSGetVersion.func TestFSFormatFS(t *testing.T) {	// Prepare for testing	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())	defer os.RemoveAll(disk) 	fsFormatPath := pathJoin(disk, minioMetaBucket, formatConfigFile) 	// Assign a new UUID.	uuid := mustGetUUID() 	// Initialize meta volume, if volume already exists ignores it.	if err := initMetaVolumeFS(disk, uuid); err != nil {		t.Fatal(err)	} 	rlk, err := initFormatFS(context.Background(), disk)	if err != nil {		t.Fatal(err)	}	rlk.Close() 	// Do the basic sanity checks to check if initFormatFS() did its job.	f, err := os.OpenFile(fsFormatPath, os.O_RDWR|os.O_SYNC, 0)	if err != nil {		t.Fatal(err)	}	defer f.Close() 	format, err := formatMetaGetFormatBackendFS(f)	if err != nil {		t.Fatal(err)	}	if format != formatBackendFS {		t.Fatalf(`expected: %s, got: %s`, formatBackendFS, format)	}	version, err := formatFSGetVersion(f)	if err != nil {		t.Fatal(err)	}	if version != formatFSVersionV2 {		t.Fatalf(`expected: %s, got: %s`, formatFSVersionV2, version)	} 	// Corrupt the format.json file and test the functions.	// formatMetaGetFormatBackendFS, formatFSGetVersion, initFormatFS should return errors.	if err = f.Truncate(0); err != nil {		t.Fatal(err)	}	if _, err = f.WriteString("b"); err != nil {		t.Fatal(err)	} 	if _, err = formatMetaGetFormatBackendFS(f); err == nil {		t.Fatal("expected to fail")	}	if _, err = formatFSGetVersion(rlk); err == nil {		t.Fatal("expected to fail")	}	if _, err = initFormatFS(context.Background(), disk); err == nil {		t.Fatal("expected to fail")	} 	// With unknown formatMetaV1.Version formatMetaGetFormatBackendFS, initFormatFS should return error.	if err = f.Truncate(0); err != nil {		t.Fatal(err)	}	// Here we set formatMetaV1.Version to "2"	if _, err = f.WriteString(`{"version":"2","format":"fs","fs":{"version":"1"}}`); err != nil {		t.Fatal(err)	}	if _, err = formatMetaGetFormatBackendFS(f); err == nil {		t.Fatal("expected to fail")	}	if _, err = initFormatFS(context.Background(), disk); err == nil {		t.Fatal("expected to fail")	}}