Add staticcheck (#1735)

Fix issues found (only costmetic) also deprecating ioutil.

Make all constants have types.

Makefile

@@ -16,6 +16,8 @@ lint:
 
 vet:
 	@GO111MODULE=on go vet ./...
+	@echo "Installing staticcheck" && go install honnef.co/go/tools/cmd/staticcheck@latest
+	${GOPATH}/bin/staticcheck -tests=false -checks="all,-ST1000,-ST1003,-ST1016,-ST1020,-ST1021,-ST1022,-ST1023,-ST1005"
 
 test:
 	@GO111MODULE=on SERVER_ENDPOINT=localhost:9000 ACCESS_KEY=minio SECRET_KEY=minio123 ENABLE_HTTPS=1 MINT_MODE=full go test -race -v ./...

api-bucket-lifecycle.go

@@ -21,7 +21,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/xml"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 
@@ -143,5 +143,5 @@ func (c *Client) getBucketLifecycle(ctx context.Context, bucketName string) ([]b
 		}
 	}
 
-	return ioutil.ReadAll(resp.Body)
+	return io.ReadAll(resp.Body)
 }

api-bucket-policy.go

@@ -18,7 +18,7 @@ package minio
 
 import (
 	"context"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
@@ -137,7 +137,7 @@ func (c *Client) getBucketPolicy(ctx context.Context, bucketName string) (string
 		}
 	}
 
-	bucketPolicyBuf, err := ioutil.ReadAll(resp.Body)
+	bucketPolicyBuf, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return "", err
 	}

api-bucket-replication.go

@@ -22,7 +22,7 @@ import (
 	"context"
 	"encoding/json"
 	"encoding/xml"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"time"
@@ -180,7 +180,7 @@ func (c *Client) GetBucketReplicationMetrics(ctx context.Context, bucketName str
 	if resp.StatusCode != http.StatusOK {
 		return s, httpRespToErrorResponse(resp, bucketName, "")
 	}
-	respBytes, err := ioutil.ReadAll(resp.Body)
+	respBytes, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return s, err
 	}

api-bucket-tagging.go

@@ -22,7 +22,6 @@ import (
 	"encoding/xml"
 	"errors"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 
@@ -58,7 +57,7 @@ func (c *Client) GetBucketTagging(ctx context.Context, bucketName string) (*tags
 		return nil, httpRespToErrorResponse(resp, bucketName, "")
 	}
 
-	defer io.Copy(ioutil.Discard, resp.Body)
+	defer io.Copy(io.Discard, resp.Body)
 	return tags.ParseBucketXML(resp.Body)
 }
 

api-compose-object.go

@@ -21,7 +21,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -516,7 +515,7 @@ func (c *Client) ComposeObject(ctx context.Context, dst CopyDestOptions, srcs ..
 				return UploadInfo{}, err
 			}
 			if dst.Progress != nil {
-				io.CopyN(ioutil.Discard, dst.Progress, end-start+1)
+				io.CopyN(io.Discard, dst.Progress, end-start+1)
 			}
 			objParts = append(objParts, complPart)
 			partIndex++

api-copy-object.go

@@ -20,7 +20,6 @@ package minio
 import (
 	"context"
 	"io"
-	"io/ioutil"
 	"net/http"
 )
 
@@ -54,7 +53,7 @@ func (c *Client) CopyObject(ctx context.Context, dst CopyDestOptions, src CopySr
 
 	// Update the progress properly after successful copy.
 	if dst.Progress != nil {
-		io.Copy(ioutil.Discard, io.LimitReader(dst.Progress, dst.Size))
+		io.Copy(io.Discard, io.LimitReader(dst.Progress, dst.Size))
 	}
 
 	cpObjRes := copyObjectResult{}

api-error-response.go

@@ -22,7 +22,6 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 )
 
@@ -108,7 +107,7 @@ const (
 func xmlDecodeAndBody(bodyReader io.Reader, v interface{}) ([]byte, error) {
 	// read the whole body (up to 1MB)
 	const maxBodyLength = 1 << 20
-	body, err := ioutil.ReadAll(io.LimitReader(bodyReader, maxBodyLength))
+	body, err := io.ReadAll(io.LimitReader(bodyReader, maxBodyLength))
 	if err != nil {
 		return nil, err
 	}
@@ -253,26 +252,6 @@ func errUnexpectedEOF(totalRead, totalSize int64, bucketName, objectName string)
 	}
 }
 
-// errInvalidBucketName - Invalid bucket name response.
-func errInvalidBucketName(message string) error {
-	return ErrorResponse{
-		StatusCode: http.StatusBadRequest,
-		Code:       "InvalidBucketName",
-		Message:    message,
-		RequestID:  "minio",
-	}
-}
-
-// errInvalidObjectName - Invalid object name response.
-func errInvalidObjectName(message string) error {
-	return ErrorResponse{
-		StatusCode: http.StatusNotFound,
-		Code:       "NoSuchKey",
-		Message:    message,
-		RequestID:  "minio",
-	}
-}
-
 // errInvalidArgument - Invalid argument response.
 func errInvalidArgument(message string) error {
 	return ErrorResponse{

api-error-response_test.go

@@ -21,7 +21,7 @@ import (
 	"bytes"
 	"encoding/xml"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"reflect"
 	"strconv"
@@ -57,7 +57,7 @@ func TestHttpRespToErrorResponse(t *testing.T) {
 		resp := &http.Response{}
 		resp.StatusCode = statusCode
 		resp.Status = http.StatusText(statusCode)
-		resp.Body = ioutil.NopCloser(bytes.NewBuffer(body))
+		resp.Body = io.NopCloser(bytes.NewBuffer(body))
 		return resp
 	}
 
@@ -113,7 +113,7 @@ func TestHttpRespToErrorResponse(t *testing.T) {
 		resp := &http.Response{
 			StatusCode: statusCode,
 			Status:     http.StatusText(statusCode),
-			Body:       ioutil.NopCloser(bytes.NewReader(nil)),
+			Body:       io.NopCloser(bytes.NewReader(nil)),
 		}
 		setCommonHeaders(resp)
 		return resp
@@ -243,34 +243,6 @@ func TestErrUnexpectedEOF(t *testing.T) {
 	}
 }
 
-// Test validates 'ErrInvalidBucketName' error response.
-func TestErrInvalidBucketName(t *testing.T) {
-	expectedResult := ErrorResponse{
-		StatusCode: http.StatusBadRequest,
-		Code:       "InvalidBucketName",
-		Message:    "Invalid Bucket name",
-		RequestID:  "minio",
-	}
-	actualResult := errInvalidBucketName("Invalid Bucket name")
-	if !reflect.DeepEqual(expectedResult, actualResult) {
-		t.Errorf("Expected result to be '%#v', but instead got '%#v'", expectedResult, actualResult)
-	}
-}
-
-// Test validates 'ErrInvalidObjectName' error response.
-func TestErrInvalidObjectName(t *testing.T) {
-	expectedResult := ErrorResponse{
-		StatusCode: http.StatusNotFound,
-		Code:       "NoSuchKey",
-		Message:    "Invalid Object Key",
-		RequestID:  "minio",
-	}
-	actualResult := errInvalidObjectName("Invalid Object Key")
-	if !reflect.DeepEqual(expectedResult, actualResult) {
-		t.Errorf("Expected result to be '%#v', but instead got '%#v'", expectedResult, actualResult)
-	}
-}
-
 // Test validates 'errInvalidArgument' response.
 func TestErrInvalidArgument(t *testing.T) {
 	expectedResult := ErrorResponse{

api-get-object_test.go

@@ -21,7 +21,6 @@ import (
 	"context"
 	"crypto/rand"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -51,7 +50,7 @@ func TestGetObjectReturnSuccess(t *testing.T) {
 	}
 
 	// We expect an error when reading back.
-	buf, err := ioutil.ReadAll(obj)
+	buf, err := io.ReadAll(obj)
 	if err != nil {
 		t.Fatalf("Expected 'nil', got %v", err)
 	}
@@ -85,7 +84,7 @@ func TestGetObjectReturnErrorIfServerTruncatesResponse(t *testing.T) {
 	}
 
 	// We expect an error when reading back.
-	if _, err = ioutil.ReadAll(obj); err != io.ErrUnexpectedEOF {
+	if _, err = io.ReadAll(obj); err != io.ErrUnexpectedEOF {
 		t.Fatalf("Expected %v, got %v", io.ErrUnexpectedEOF, err)
 	}
 }
@@ -114,7 +113,7 @@ func TestGetObjectReturnErrorIfServerTruncatesResponseDouble(t *testing.T) {
 	}
 
 	// We expect an error when reading back.
-	if _, err = ioutil.ReadAll(obj); err != io.ErrUnexpectedEOF {
+	if _, err = io.ReadAll(obj); err != io.ErrUnexpectedEOF {
 		t.Fatalf("Expected %v, got %v", io.ErrUnexpectedEOF, err)
 	}
 }
@@ -143,7 +142,7 @@ func TestGetObjectReturnErrorIfServerSendsMore(t *testing.T) {
 	}
 
 	// We expect an error when reading back.
-	if _, err = ioutil.ReadAll(obj); err != io.ErrUnexpectedEOF {
+	if _, err = io.ReadAll(obj); err != io.ErrUnexpectedEOF {
 		t.Fatalf("Expected %v, got %v", io.ErrUnexpectedEOF, err)
 	}
 }

api-list.go

@@ -897,6 +897,8 @@ func (c *Client) listMultipartUploadsQuery(ctx context.Context, bucketName, keyM
 }
 
 // listObjectParts list all object parts recursively.
+//
+//lint:ignore U1000 Keep this around
 func (c *Client) listObjectParts(ctx context.Context, bucketName, objectName, uploadID string) (partsInfo map[int]ObjectPart, err error) {
 	// Part number marker for the next batch of request.
 	var nextPartNumberMarker int

api-put-object-multipart.go

@@ -26,7 +26,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"sort"
@@ -412,7 +411,7 @@ func (c *Client) completeMultipartUpload(ctx context.Context, bucketName, object
 
 	// Read resp.Body into a []bytes to parse for Error response inside the body
 	var b []byte
-	b, err = ioutil.ReadAll(resp.Body)
+	b, err = io.ReadAll(resp.Body)
 	if err != nil {
 		return UploadInfo{}, err
 	}

api-putobject-snowball.go

@@ -24,7 +24,6 @@ import (
 	"context"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"strings"
 	"sync"
@@ -107,7 +106,7 @@ func (c Client) PutObjectsSnowball(ctx context.Context, bucketName string, opts
 			return nopReadSeekCloser{bytes.NewReader(b.Bytes())}, int64(b.Len()), nil
 		}
 	} else {
-		f, err := ioutil.TempFile("", "s3-putsnowballobjects-*")
+		f, err := os.CreateTemp("", "s3-putsnowballobjects-*")
 		if err != nil {
 			return err
 		}

api-select.go

@@ -41,8 +41,8 @@ type CSVFileHeaderInfo string
 // Constants for file header info.
 const (
 	CSVFileHeaderInfoNone   CSVFileHeaderInfo = "NONE"
-	CSVFileHeaderInfoIgnore                   = "IGNORE"
-	CSVFileHeaderInfoUse                      = "USE"
+	CSVFileHeaderInfoIgnore CSVFileHeaderInfo = "IGNORE"
+	CSVFileHeaderInfoUse    CSVFileHeaderInfo = "USE"
 )
 
 // SelectCompressionType - is the parameter for what type of compression is
@@ -52,15 +52,15 @@ type SelectCompressionType string
 // Constants for compression types under select API.
 const (
 	SelectCompressionNONE SelectCompressionType = "NONE"
-	SelectCompressionGZIP                       = "GZIP"
-	SelectCompressionBZIP                       = "BZIP2"
+	SelectCompressionGZIP SelectCompressionType = "GZIP"
+	SelectCompressionBZIP SelectCompressionType = "BZIP2"
 
 	// Non-standard compression schemes, supported by MinIO hosts:
 
-	SelectCompressionZSTD   = "ZSTD"   // Zstandard compression.
-	SelectCompressionLZ4    = "LZ4"    // LZ4 Stream
-	SelectCompressionS2     = "S2"     // S2 Stream
-	SelectCompressionSNAPPY = "SNAPPY" // Snappy stream
+	SelectCompressionZSTD   SelectCompressionType = "ZSTD"   // Zstandard compression.
+	SelectCompressionLZ4    SelectCompressionType = "LZ4"    // LZ4 Stream
+	SelectCompressionS2     SelectCompressionType = "S2"     // S2 Stream
+	SelectCompressionSNAPPY SelectCompressionType = "SNAPPY" // Snappy stream
 )
 
 // CSVQuoteFields - is the parameter for how CSV fields are quoted.
@@ -69,7 +69,7 @@ type CSVQuoteFields string
 // Constants for csv quote styles.
 const (
 	CSVQuoteFieldsAlways   CSVQuoteFields = "Always"
-	CSVQuoteFieldsAsNeeded                = "AsNeeded"
+	CSVQuoteFieldsAsNeeded CSVQuoteFields = "AsNeeded"
 )
 
 // QueryExpressionType - is of what syntax the expression is, this should only
@@ -87,7 +87,7 @@ type JSONType string
 // Constants for JSONTypes.
 const (
 	JSONDocumentType JSONType = "DOCUMENT"
-	JSONLinesType             = "LINES"
+	JSONLinesType    JSONType = "LINES"
 )
 
 // ParquetInputOptions parquet input specific options
@@ -378,8 +378,8 @@ type SelectObjectType string
 // Constants for input data types.
 const (
 	SelectObjectTypeCSV     SelectObjectType = "CSV"
-	SelectObjectTypeJSON                     = "JSON"
-	SelectObjectTypeParquet                  = "Parquet"
+	SelectObjectTypeJSON    SelectObjectType = "JSON"
+	SelectObjectTypeParquet SelectObjectType = "Parquet"
 )
 
 // preludeInfo is used for keeping track of necessary information from the
@@ -416,7 +416,7 @@ type messageType string
 
 const (
 	errorMsg  messageType = "error"
-	commonMsg             = "event"
+	commonMsg messageType = "event"
 )
 
 // eventType represents the type of event.
@@ -425,9 +425,9 @@ type eventType string
 // list of event-types returned by Select API.
 const (
 	endEvent      eventType = "End"
-	recordsEvent            = "Records"
-	progressEvent           = "Progress"
-	statsEvent              = "Stats"
+	recordsEvent  eventType = "Records"
+	progressEvent eventType = "Progress"
+	statsEvent    eventType = "Stats"
 )
 
 // contentType represents content type of event.