ci: fix linter errors

Fixes few classes of errors:
* use errors.Is even for io.EOF
* use errors.As instead of casting to a particular type
* use context in http requests
* fix bug with appending

Change-Id: I1a398cf933c6eed744170e5dd5f2fdff8878ab4c

Author: egonelbre

encryption/transform.go

@@ -6,6 +6,7 @@ package encryption
 import (
 	"bytes"
 	"context"
+	"errors"
 	"io"
 	"io/ioutil"
 
@@ -88,14 +89,14 @@ func (t *transformedReader) Read(p []byte) (n int, err error) {
 		// the next block
 		b, err := io.ReadFull(t.r, t.inbuf)
 		t.bytesRead += b
-		if err == io.EOF && int64(t.bytesRead) < t.expectedSize {
+		if errors.Is(err, io.EOF) && int64(t.bytesRead) < t.expectedSize {
 			return 0, io.ErrUnexpectedEOF
 		} else if err != nil {
 			return 0, err
 		}
 		t.outbuf, err = t.t.Transform(t.outbuf, t.inbuf, t.blockNum)
 		if err != nil {
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				return 0, err
 			}
 			return 0, Error.Wrap(err)
@@ -178,7 +179,7 @@ func (t *transformedRanger) Range(ctx context.Context, offset, length int64) (_
 	_, err = io.CopyN(ioutil.Discard, tr,
 		offset-firstBlock*int64(t.t.OutBlockSize()))
 	if err != nil {
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			return nil, io.ErrUnexpectedEOF
 		}
 		return nil, Error.Wrap(err)

errs2/ignore.go

@@ -14,7 +14,7 @@ import (
 // IsCanceled returns true, when the error is a cancellation.
 func IsCanceled(err error) bool {
 	return errs.IsFunc(err, func(err error) bool {
-		return err == context.Canceled || //nolint: goerr113
+		return err == context.Canceled || //nolint: errorlint, goerr113
 			rpcstatus.Code(err) == rpcstatus.Canceled
 	})
 }

fpath/os.go

@@ -4,6 +4,7 @@
 package fpath
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -84,7 +85,7 @@ func IsValidSetupDir(name string) (ok bool, err error) {
 	for {
 		var filenames []string
 		filenames, err = f.Readdirnames(100)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// nothing more
 			return true, nil
 		} else if err != nil {

identity/identity.go

@@ -442,8 +442,8 @@ func (fi *FullIdentity) RawChain() [][]byte {
 // RawRestChain returns the rest (excluding leaf and CA) of the certificate chain as a 2d byte slice.
 func (fi *FullIdentity) RawRestChain() [][]byte {
 	rawChain := make([][]byte, len(fi.RestChain))
-	for _, cert := range fi.RestChain {
-		rawChain = append(rawChain, cert.Raw)
+	for i, cert := range fi.RestChain {
+		rawChain[i] = cert.Raw
 	}
 	return rawChain
 }

peertls/peertls_test.go

@@ -9,6 +9,7 @@ import (
 	"crypto/x509/pkix"
 	"encoding/asn1"
 	"encoding/gob"
+	"errors"
 	"testing"
 	"time"
 
@@ -120,8 +121,8 @@ func TestVerifyPeerCertChains(t *testing.T) {
 	assert.NoError(t, err)
 
 	err = peertls.VerifyPeerFunc(peertls.VerifyPeerCertChains)([][]byte{leafCert.Raw, caCert.Raw}, nil)
-	nonTempErr, ok := err.(peertls.NonTemporaryError)
-	require.True(t, ok)
+	var nonTempErr peertls.NonTemporaryError
+	require.True(t, errors.As(err, &nonTempErr))
 	assert.True(t, peertls.ErrVerifyPeerCert.Has(nonTempErr.Err()))
 	assert.True(t, peertls.ErrVerifyCertificateChain.Has(nonTempErr.Err()))
 }
@@ -151,8 +152,8 @@ func TestVerifyCAWhitelist(t *testing.T) {
 
 	t.Run("no valid signed extension, non-empty whitelist", func(t *testing.T) {
 		err = peertls.VerifyPeerFunc(peertls.VerifyCAWhitelist([]*x509.Certificate{unrelatedCert}))([][]byte{leafCert.Raw, caCert.Raw}, nil)
-		nonTempErr, ok := err.(peertls.NonTemporaryError)
-		require.True(t, ok)
+		var nonTempErr peertls.NonTemporaryError
+		require.True(t, errors.As(err, &nonTempErr))
 		assert.True(t, peertls.ErrVerifyCAWhitelist.Has(nonTempErr.Err()))
 	})
 

ranger/file.go

@@ -5,6 +5,7 @@ package ranger
 
 import (
 	"context"
+	"errors"
 	"io"
 	"os"
 
@@ -69,7 +70,7 @@ func (reader *FileReader) Read(data []byte) (n int, err error) {
 	}
 	n, err = reader.file.Read(data)
 	reader.remaining -= int64(n)
-	if err == io.EOF && reader.remaining == 0 {
+	if errors.Is(err, io.EOF) && reader.remaining == 0 {
 		err = nil
 	}
 	return

ranger/httpranger/http.go

@@ -25,7 +25,11 @@ type httpRanger struct {
 func HTTPRanger(ctx context.Context, url string) (_ ranger.Ranger, err error) {
 	defer mon.Task()(&ctx)(&err)
 	/* #nosec G107 */ // The callers must control the soure of the url value
-	resp, err := http.Head(url)
+	req, err := http.NewRequestWithContext(ctx, http.MethodHead, url, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return nil, err
 	}
@@ -54,7 +58,7 @@ func HTTPRanger(ctx context.Context, url string) (_ ranger.Ranger, err error) {
 // HTTPRangerSize creates an HTTPRanger with known size.
 // Use it if you know the content size. This will safe the extra HEAD request
 // for retrieving the content size.
-func HTTPRangerSize(url string, size int64) ranger.Ranger { // nolint:golint
+func HTTPRangerSize(url string, size int64) ranger.Ranger { // nolint:golint,revive
 	return &httpRanger{
 		URL:  url,
 		size: size,
@@ -82,7 +86,7 @@ func (r *httpRanger) Range(ctx context.Context, offset, length int64) (_ io.Read
 		return ioutil.NopCloser(bytes.NewReader([]byte{})), nil
 	}
 	client := &http.Client{}
-	req, err := http.NewRequest("GET", r.URL, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, r.URL, nil)
 	if err != nil {
 		return nil, err
 	}

readcloser/multi.go

@@ -4,6 +4,7 @@
 package readcloser
 
 import (
+	"errors"
 	"io"
 
 	"github.com/zeebo/errs"
@@ -44,15 +45,15 @@ func (mr *multiReadCloser) Read(p []byte) (n int, err error) {
 			}
 		}
 		n, err = mr.readers[0].Read(p)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			err = mr.readers[0].Close()
 			// Use eofReader instead of nil to avoid nil panic
 			// after performing flatten (Issue 18232).
 			mr.readers[0] = eofReadCloser{} // permit earlier GC
 			mr.readers = mr.readers[1:]
 		}
-		if n > 0 || err != io.EOF {
-			if err == io.EOF && len(mr.readers) > 0 {
+		if n > 0 || !errors.Is(err, io.EOF) {
+			if errors.Is(err, io.EOF) && len(mr.readers) > 0 {
 				// Don't return EOF yet. More readers remain.
 				err = nil
 			}

rpc/rpccache/cache_test.go

@@ -416,7 +416,7 @@ func runBenchmarkFilterSlice(b *testing.B, n int) {
 	for i := 0; i < b.N; i++ {
 		ent := ents[0]
 		ents = filterEntry(ents, ent)
-		ents = append(ents, ent)
+		ents = append(ents, ent) //nolint: makezero // the test removes from slice and adds it back
 	}
 }
 

rpc/rpcstatus/status.go

@@ -6,6 +6,7 @@ package rpcstatus
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/zeebo/errs"
@@ -42,12 +43,12 @@ const (
 func Code(err error) StatusCode {
 	// special case: if the error is context canceled or deadline exceeded, the code
 	// must be those. additionally, grpc returns OK for a nil error, so we will, too.
-	switch err {
-	case nil:
+	switch {
+	case err == nil:
 		return OK
-	case context.Canceled:
+	case errors.Is(err, context.Canceled):
 		return Canceled
-	case context.DeadlineExceeded:
+	case errors.Is(err, context.DeadlineExceeded):
 		return DeadlineExceeded
 	default:
 		if code := StatusCode(drpcerr.Code(err)); code != Unknown {
@@ -68,10 +69,9 @@ func Wrap(code StatusCode, err error) error {
 		code: code,
 	}
 
-	if ee, ok := err.(errsError); ok {
-		ce.errsError = ee
-	} else {
-		ce.errsError = errs.Wrap(err).(errsError)
+	if !errors.As(err, &ce.errsError) {
+		werr := errs.Wrap(err)
+		errors.As(werr, &ce.errsError)
 	}
 
 	return ce

strictcsv/unmarshal.go

@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"encoding"
 	"encoding/csv"
+	"errors"
 	"io"
 	"reflect"
 	"sort"
@@ -116,7 +117,7 @@ func Read(r io.Reader, obj interface{}) error {
 	for {
 		record, err := csvr.Read()
 		if err != nil {
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				pv.Elem().Set(v)
 				return nil
 			}

sync2/pipe.go

@@ -231,7 +231,7 @@ func NewMultiPipeFile(tempdir string, pipeCount, pipeSize int64) (*MultiPipe, er
 	if err != nil {
 		closeErr := tempfile.Close()
 		if closeErr != nil {
-			return nil, fmt.Errorf("%v/%v", err, closeErr)
+			return nil, fmt.Errorf("%w/%v", err, closeErr)
 		}
 		return nil, err
 	}

sync2/tee.go

@@ -4,6 +4,7 @@
 package sync2
 
 import (
+	"errors"
 	"io"
 	"sync"
 	"sync/atomic"
@@ -84,7 +85,7 @@ func (reader *teeReader) Read(data []byte) (n int, err error) {
 	tee.mu.Lock()
 
 	// fail fast on writer error
-	if tee.writerErr != nil && tee.writerErr != io.EOF {
+	if tee.writerErr != nil && !errors.Is(tee.writerErr, io.EOF) {
 		tee.mu.Unlock()
 		return 0, tee.writerErr
 	}