all: Bunch of more linter fixes (#5500)

lib/beacon/broadcast.go

@@ -126,9 +126,9 @@ func (w *broadcastWriter) Serve() {
 		for _, ip := range dsts {
 			dst := &net.UDPAddr{IP: ip, Port: w.port}
 
-			conn.SetWriteDeadline(time.Now().Add(time.Second))
+			_ = conn.SetWriteDeadline(time.Now().Add(time.Second))
 			_, err := conn.WriteTo(bs, dst)
-			conn.SetWriteDeadline(time.Time{})
+			_ = conn.SetWriteDeadline(time.Time{})
 
 			if err, ok := err.(net.Error); ok && err.Timeout() {
 				// Write timeouts should not happen. We treat it as a fatal

lib/beacon/multicast.go

@@ -117,9 +117,9 @@ func (w *multicastWriter) Serve() {
 		success := 0
 		for _, intf := range intfs {
 			wcm.IfIndex = intf.Index
-			pconn.SetWriteDeadline(time.Now().Add(time.Second))
+			_ = pconn.SetWriteDeadline(time.Now().Add(time.Second))
 			_, err = pconn.WriteTo(bs, wcm, gaddr)
-			pconn.SetWriteDeadline(time.Time{})
+			_ = pconn.SetWriteDeadline(time.Time{})
 
 			if err != nil {
 				l.Debugln(err, "on write to", gaddr, intf.Name)

lib/config/config.go

@@ -71,9 +71,9 @@ func New(myID protocol.DeviceID) Configuration {
 	cfg.Version = CurrentVersion
 	cfg.OriginalVersion = CurrentVersion
 
-	util.SetDefaults(&cfg)
-	util.SetDefaults(&cfg.Options)
-	util.SetDefaults(&cfg.GUI)
+	_ = util.SetDefaults(&cfg)
+	_ = util.SetDefaults(&cfg.Options)
+	_ = util.SetDefaults(&cfg.GUI)
 
 	// Can't happen.
 	if err := cfg.prepare(myID); err != nil {
@@ -86,9 +86,9 @@ func New(myID protocol.DeviceID) Configuration {
 func ReadXML(r io.Reader, myID protocol.DeviceID) (Configuration, error) {
 	var cfg Configuration
 
-	util.SetDefaults(&cfg)
-	util.SetDefaults(&cfg.Options)
-	util.SetDefaults(&cfg.GUI)
+	_ = util.SetDefaults(&cfg)
+	_ = util.SetDefaults(&cfg.Options)
+	_ = util.SetDefaults(&cfg.GUI)
 
 	if err := xml.NewDecoder(r).Decode(&cfg); err != nil {
 		return Configuration{}, err
@@ -104,9 +104,9 @@ func ReadXML(r io.Reader, myID protocol.DeviceID) (Configuration, error) {
 func ReadJSON(r io.Reader, myID protocol.DeviceID) (Configuration, error) {
 	var cfg Configuration
 
-	util.SetDefaults(&cfg)
-	util.SetDefaults(&cfg.Options)
-	util.SetDefaults(&cfg.GUI)
+	_ = util.SetDefaults(&cfg)
+	_ = util.SetDefaults(&cfg.Options)
+	_ = util.SetDefaults(&cfg.GUI)
 
 	bs, err := ioutil.ReadAll(r)
 	if err != nil {
@@ -211,7 +211,7 @@ found:
 }
 
 func (cfg *Configuration) clean() error {
-	util.FillNilSlices(&cfg.Options)
+	_ = util.FillNilSlices(&cfg.Options)
 
 	// Prepare folders and check for duplicates. Duplicates are bad and
 	// dangerous, can't currently be resolved in the GUI, and shouldn't
@@ -477,7 +477,7 @@ func convertV22V23(cfg *Configuration) {
 			err = fs.Remove(DefaultMarkerName)
 			if err == nil {
 				err = fs.Mkdir(DefaultMarkerName, permBits)
-				fs.Hide(DefaultMarkerName) // ignore error
+				_ = fs.Hide(DefaultMarkerName) // ignore error
 			}
 			if err != nil {
 				l.Infoln("Failed to upgrade folder marker:", err)
@@ -810,13 +810,13 @@ func cleanSymlinks(filesystem fs.Filesystem, dir string) {
 		// should leave alone. Deduplicated files, for example.
 		return
 	}
-	filesystem.Walk(dir, func(path string, info fs.FileInfo, err error) error {
+	_ = filesystem.Walk(dir, func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
 		if info.IsSymlink() {
 			l.Infoln("Removing incorrectly versioned symlink", path)
-			filesystem.Remove(path)
+			_ = filesystem.Remove(path)
 			return fs.SkipDir
 		}
 		return nil

lib/config/config_test.go

@@ -548,7 +548,7 @@ func TestPrepare(t *testing.T) {
 		t.Error("Expected nil")
 	}
 
-	cfg.prepare(device1)
+	_ = cfg.prepare(device1)
 
 	if cfg.Folders == nil || cfg.Devices == nil || cfg.Options.ListenAddresses == nil {
 		t.Error("Unexpected nil")
@@ -627,7 +627,7 @@ func TestPullOrder(t *testing.T) {
 
 	buf := new(bytes.Buffer)
 	cfg := wrapper.RawCopy()
-	cfg.WriteXML(buf)
+	_ = cfg.WriteXML(buf)
 
 	t.Logf("%s", buf.Bytes())
 
@@ -918,7 +918,7 @@ func TestIssue4219(t *testing.T) {
 		],
 		"folders": [
 			{
-				"id": "abcd123", 
+				"id": "abcd123",
 				"devices":[
 					{"deviceID": "GYRZZQB-IRNPV4Z-T7TC52W-EQYJ3TT-FDQW6MW-DFLMU42-SSSU6EM-FBK2VAY"}
 				]
@@ -1080,7 +1080,7 @@ func TestDeviceConfigObservedNotNil(t *testing.T) {
 		},
 	}
 
-	cfg.prepare(device1)
+	_ = cfg.prepare(device1)
 
 	for _, dev := range cfg.Devices {
 		if dev.IgnoredFolders == nil {

lib/config/folderconfiguration.go

@@ -142,7 +142,7 @@ func (f *FolderConfiguration) CreateMarker() error {
 	} else if err := dir.Sync(); err != nil {
 		l.Debugln("folder marker: fsync . failed:", err)
 	}
-	fs.Hide(DefaultMarkerName)
+	_ = fs.Hide(DefaultMarkerName)
 
 	return nil
 }

lib/config/wrapper.go

@@ -448,7 +448,7 @@ func (w *Wrapper) MyName() string {
 }
 
 func (w *Wrapper) AddOrUpdatePendingDevice(device protocol.DeviceID, name, address string) {
-	defer w.Save()
+	defer func() { _ = w.Save() }()
 
 	w.mut.Lock()
 	defer w.mut.Unlock()
@@ -471,7 +471,7 @@ func (w *Wrapper) AddOrUpdatePendingDevice(device protocol.DeviceID, name, addre
 }
 
 func (w *Wrapper) AddOrUpdatePendingFolder(id, label string, device protocol.DeviceID) {
-	defer w.Save()
+	defer func() { _ = w.Save() }()
 
 	w.mut.Lock()
 	defer w.mut.Unlock()

lib/connections/limiter.go

@@ -257,17 +257,17 @@ func take(waiter waiter, tokens int) {
 	if tokens < limiterBurstSize {
 		// This is the by far more common case so we get it out of the way
 		// early.
-		waiter.WaitN(context.TODO(), tokens)
+		_ = waiter.WaitN(context.TODO(), tokens)
 		return
 	}
 
 	for tokens > 0 {
 		// Consume limiterBurstSize tokens at a time until we're done.
 		if tokens > limiterBurstSize {
-			waiter.WaitN(context.TODO(), limiterBurstSize)
+			_ = waiter.WaitN(context.TODO(), limiterBurstSize)
 			tokens -= limiterBurstSize
 		} else {
-			waiter.WaitN(context.TODO(), tokens)
+			_ = waiter.WaitN(context.TODO(), tokens)
 			tokens = 0
 		}
 	}

lib/connections/service.go

@@ -190,7 +190,7 @@ next:
 			continue
 		}
 
-		c.SetDeadline(time.Now().Add(20 * time.Second))
+		_ = c.SetDeadline(time.Now().Add(20 * time.Second))
 		hello, err := protocol.ExchangeHello(c, s.model.GetHello(remoteID))
 		if err != nil {
 			if protocol.IsVersionMismatch(err) {
@@ -214,7 +214,7 @@ next:
 			c.Close()
 			continue
 		}
-		c.SetDeadline(time.Time{})
+		_ = c.SetDeadline(time.Time{})
 
 		// The Model will return an error for devices that we don't want to
 		// have a connection with for whatever reason, for example unknown devices.
@@ -569,7 +569,7 @@ func (s *Service) CommitConfiguration(from, to config.Configuration) bool {
 	for addr, listener := range s.listeners {
 		if _, ok := seen[addr]; !ok || listener.Factory().Valid(to) != nil {
 			l.Debugln("Stopping listener", addr)
-			s.listenerSupervisor.Remove(s.listenerTokens[addr])
+			_ = s.listenerSupervisor.Remove(s.listenerTokens[addr])
 			delete(s.listenerTokens, addr)
 			delete(s.listeners, addr)
 		}
@@ -582,7 +582,7 @@ func (s *Service) CommitConfiguration(from, to config.Configuration) bool {
 		s.natServiceToken = &token
 	} else if !to.Options.NATEnabled && s.natServiceToken != nil {
 		l.Debugln("Stopping NAT service")
-		s.Remove(*s.natServiceToken)
+		_ = s.Remove(*s.natServiceToken)
 		s.natServiceToken = nil
 	}
 
@@ -717,8 +717,8 @@ func warningFor(dev protocol.DeviceID, msg string) {
 }
 
 func tlsTimedHandshake(tc *tls.Conn) error {
-	tc.SetDeadline(time.Now().Add(tlsHandshakeTimeout))
-	defer tc.SetDeadline(time.Time{})
+	_ = tc.SetDeadline(time.Now().Add(tlsHandshakeTimeout))
+	defer func() { _ = tc.SetDeadline(time.Time{}) }()
 	return tc.Handshake()
 }
 

lib/connections/structs.go

@@ -89,8 +89,8 @@ func (c internalConn) Close() {
 	// *tls.Conn.Close() does more than it says on the tin. Specifically, it
 	// sends a TLS alert message, which might block forever if the
 	// connection is dead and we don't have a deadline set.
-	c.SetWriteDeadline(time.Now().Add(250 * time.Millisecond))
-	c.Conn.Close()
+	_ = c.SetWriteDeadline(time.Now().Add(250 * time.Millisecond))
+	_ = c.Conn.Close()
 }
 
 func (c internalConn) Type() string {

lib/connections/tcp_listen.go

@@ -83,7 +83,7 @@ func (t *tcpListener) Serve() {
 	const maxAcceptFailures = 10
 
 	for {
-		listener.SetDeadline(time.Now().Add(time.Second))
+		_ = listener.SetDeadline(time.Now().Add(time.Second))
 		conn, err := listener.Accept()
 		select {
 		case <-t.stop:

lib/db/db_test.go

@@ -19,7 +19,7 @@ func TestIgnoredFiles(t *testing.T) {
 		t.Fatal(err)
 	}
 	db := NewLowlevel(ldb, "<memory>")
-	UpdateSchema(db)
+	_ = UpdateSchema(db)
 
 	fs := NewFileSet("test", fs.NewFilesystem(fs.FilesystemTypeBasic, "."), db)
 
@@ -204,7 +204,7 @@ func TestUpdate0to3(t *testing.T) {
 
 func TestDowngrade(t *testing.T) {
 	db := OpenMemory()
-	UpdateSchema(db) // sets the min version etc
+	_ = UpdateSchema(db) // sets the min version etc
 
 	// Bump the database version to something newer than we actually support
 	miscDB := NewMiscDataNamespace(db)

lib/db/instance.go

@@ -13,12 +13,9 @@ import (
 
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syndtr/goleveldb/leveldb"
-	"github.com/syndtr/goleveldb/leveldb/iterator"
 	"github.com/syndtr/goleveldb/leveldb/util"
 )
 
-type deletionHandler func(t readWriteTransaction, folder, device, name []byte, dbi iterator.Iterator)
-
 type instance struct {
 	*Lowlevel
 	keyer keyer

lib/db/namespaced.go

@@ -61,7 +61,7 @@ func (n *NamespacedKV) Reset() {
 func (n *NamespacedKV) PutInt64(key string, val int64) {
 	var valBs [8]byte
 	binary.BigEndian.PutUint64(valBs[:], uint64(val))
-	n.db.Put(n.prefixedKey(key), valBs[:], nil)
+	_ = n.db.Put(n.prefixedKey(key), valBs[:], nil)
 }
 
 // Int64 returns the stored value interpreted as an int64 and a boolean that
@@ -79,7 +79,7 @@ func (n *NamespacedKV) Int64(key string) (int64, bool) {
 // type) is overwritten.
 func (n *NamespacedKV) PutTime(key string, val time.Time) {
 	valBs, _ := val.MarshalBinary() // never returns an error
-	n.db.Put(n.prefixedKey(key), valBs, nil)
+	_ = n.db.Put(n.prefixedKey(key), valBs, nil)
 }
 
 // Time returns the stored value interpreted as a time.Time and a boolean
@@ -97,7 +97,7 @@ func (n NamespacedKV) Time(key string) (time.Time, bool) {
 // PutString stores a new string. Any existing value (even if of another type)
 // is overwritten.
 func (n *NamespacedKV) PutString(key, val string) {
-	n.db.Put(n.prefixedKey(key), []byte(val), nil)
+	_ = n.db.Put(n.prefixedKey(key), []byte(val), nil)
 }
 
 // String returns the stored value interpreted as a string and a boolean that
@@ -113,7 +113,7 @@ func (n NamespacedKV) String(key string) (string, bool) {
 // PutBytes stores a new byte slice. Any existing value (even if of another type)
 // is overwritten.
 func (n *NamespacedKV) PutBytes(key string, val []byte) {
-	n.db.Put(n.prefixedKey(key), val, nil)
+	_ = n.db.Put(n.prefixedKey(key), val, nil)
 }
 
 // Bytes returns the stored value as a raw byte slice and a boolean that
@@ -130,9 +130,9 @@ func (n NamespacedKV) Bytes(key string) ([]byte, bool) {
 // is overwritten.
 func (n *NamespacedKV) PutBool(key string, val bool) {
 	if val {
-		n.db.Put(n.prefixedKey(key), []byte{0x0}, nil)
+		_ = n.db.Put(n.prefixedKey(key), []byte{0x0}, nil)
 	} else {
-		n.db.Put(n.prefixedKey(key), []byte{0x1}, nil)
+		_ = n.db.Put(n.prefixedKey(key), []byte{0x1}, nil)
 	}
 }
 
@@ -149,7 +149,7 @@ func (n NamespacedKV) Bool(key string) (bool, bool) {
 // Delete deletes the specified key. It is allowed to delete a nonexistent
 // key.
 func (n NamespacedKV) Delete(key string) {
-	n.db.Delete(n.prefixedKey(key), nil)
+	_ = n.db.Delete(n.prefixedKey(key), nil)
 }
 
 func (n NamespacedKV) prefixedKey(key string) []byte {

lib/db/set.go

@@ -101,7 +101,7 @@ func (s *FileSet) recalcCounts() {
 	})
 
 	s.meta.SetCreated()
-	s.meta.toDB(s.db, []byte(s.folder))
+	_ = s.meta.toDB(s.db, []byte(s.folder))
 }
 
 func (s *FileSet) Drop(device protocol.DeviceID) {
@@ -127,7 +127,7 @@ func (s *FileSet) Drop(device protocol.DeviceID) {
 		s.meta.resetAll(device)
 	}
 
-	s.meta.toDB(s.db, []byte(s.folder))
+	_ = s.meta.toDB(s.db, []byte(s.folder))
 }
 
 func (s *FileSet) Update(device protocol.DeviceID, fs []protocol.FileInfo) {
@@ -141,7 +141,7 @@ func (s *FileSet) Update(device protocol.DeviceID, fs []protocol.FileInfo) {
 	s.updateMutex.Lock()
 	defer s.updateMutex.Unlock()
 
-	defer s.meta.toDB(s.db, []byte(s.folder))
+	defer func() { _ = s.meta.toDB(s.db, []byte(s.folder)) }()
 
 	if device == protocol.LocalDeviceID {
 		// For the local device we have a bunch of metadata to track.
@@ -295,7 +295,7 @@ func DropDeltaIndexIDs(db *Lowlevel) {
 	dbi := db.NewIterator(util.BytesPrefix([]byte{KeyTypeIndexID}), nil)
 	defer dbi.Release()
 	for dbi.Next() {
-		db.Delete(dbi.Key(), nil)
+		_ = db.Delete(dbi.Key(), nil)
 	}
 }
 

lib/db/smallindex.go

@@ -82,7 +82,7 @@ func (i *smallIndex) ID(val []byte) uint32 {
 	key := make([]byte, len(i.prefix)+8) // prefix plus uint32 id
 	copy(key, i.prefix)
 	binary.BigEndian.PutUint32(key[len(i.prefix):], id)
-	i.db.Put(key, val, nil)
+	_ = i.db.Put(key, val, nil)
 
 	i.mut.Unlock()
 	return id
@@ -115,7 +115,7 @@ func (i *smallIndex) Delete(val []byte) {
 		// Put an empty value into the database. This indicates that the
 		// entry does not exist any more and prevents the ID from being
 		// reused in the future.
-		i.db.Put(key, []byte{}, nil)
+		_ = i.db.Put(key, []byte{}, nil)
 
 		// Delete reverse mapping.
 		delete(i.id2val, id)

lib/db/transactions.go

@@ -127,7 +127,7 @@ func (t readWriteTransaction) updateGlobal(gk, keyBuf, folder, device []byte, fi
 
 	var fl VersionList
 	if svl, err := t.Get(gk, nil); err == nil {
-		fl.Unmarshal(svl) // Ignore error, continue with empty fl
+		_ = fl.Unmarshal(svl) // Ignore error, continue with empty fl
 	}
 	fl, removedFV, removedAt, insertedAt := fl.update(folder, device, file, t.readOnlyTransaction)
 	if insertedAt == -1 {

lib/db/util_test.go

@@ -23,13 +23,17 @@ func writeJSONS(w io.Writer, db *leveldb.DB) {
 	defer it.Release()
 	enc := json.NewEncoder(w)
 	for it.Next() {
-		enc.Encode(map[string][]byte{
+		_ = enc.Encode(map[string][]byte{
 			"k": it.Key(),
 			"v": it.Value(),
 		})
 	}
 }
 
+// we know this function isn't generally used, nonetheless we want it in
+// here and the linter to not complain.
+var _ = writeJSONS
+
 // openJSONS reads a JSON stream file into a leveldb.DB
 func openJSONS(file string) (*leveldb.DB, error) {
 	fd, err := os.Open(file)
@@ -50,7 +54,7 @@ func openJSONS(file string) (*leveldb.DB, error) {
 			return nil, err
 		}
 
-		db.Put(row["k"], row["v"], nil)
+		_ = db.Put(row["k"], row["v"], nil)
 	}
 
 	return db, nil

lib/dialer/internal.go

@@ -62,7 +62,7 @@ func dialWithFallback(proxyDialFunc dialFunc, fallbackDialFunc dialFunc, network
 	conn, err := proxyDialFunc(network, addr)
 	if err == nil {
 		l.Debugf("Dialing %s address %s via proxy - success, %s -> %s", network, addr, conn.LocalAddr(), conn.RemoteAddr())
-		SetTCPOptions(conn)
+		_ = SetTCPOptions(conn)
 		return dialerConn{
 			conn, newDialerAddr(network, addr),
 		}, nil
@@ -76,7 +76,7 @@ func dialWithFallback(proxyDialFunc dialFunc, fallbackDialFunc dialFunc, network
 	conn, err = fallbackDialFunc(network, addr)
 	if err == nil {
 		l.Debugf("Dialing %s address %s via fallback - success, %s -> %s", network, addr, conn.LocalAddr(), conn.RemoteAddr())
-		SetTCPOptions(conn)
+		_ = SetTCPOptions(conn)
 	} else {
 		l.Debugf("Dialing %s address %s via fallback - error %s", network, addr, err)
 	}

lib/discover/cache_test.go

@@ -96,7 +96,7 @@ func TestCacheSlowLookup(t *testing.T) {
 	// Start a lookup, which will take at least a second
 
 	t0 := time.Now()
-	go c.Lookup(protocol.LocalDeviceID)
+	go func() { _, _ = c.Lookup(protocol.LocalDeviceID) }()
 	<-started // The slow lookup method has been called so we're inside the lock
 
 	// It should be possible to get ChildErrors while it's running

lib/discover/global_test.go

@@ -77,7 +77,7 @@ func TestGlobalOverHTTP(t *testing.T) {
 	s := new(fakeDiscoveryServer)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handler)
-	go http.Serve(list, mux)
+	go func() { _ = http.Serve(list, mux) }()
 
 	// This should succeed
 	addresses, err := testLookup("http://" + list.Addr().String() + "?insecure&noannounce")
@@ -125,7 +125,7 @@ func TestGlobalOverHTTPS(t *testing.T) {
 	s := new(fakeDiscoveryServer)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handler)
-	go http.Serve(list, mux)
+	go func() { _ = http.Serve(list, mux) }()
 
 	// With default options the lookup code expects the server certificate to
 	// check out according to the usual CA chains etc. That won't be the case
@@ -190,7 +190,7 @@ func TestGlobalAnnounce(t *testing.T) {
 	s := new(fakeDiscoveryServer)
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handler)
-	go http.Serve(list, mux)
+	go func() { _ = http.Serve(list, mux) }()
 
 	url := "https://" + list.Addr().String() + "?insecure"
 	disco, err := NewGlobal(url, cert, new(fakeAddressLister))
@@ -242,7 +242,7 @@ func (s *fakeDiscoveryServer) handler(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(204)
 	} else {
 		w.Header().Set("Content-Type", "application/json")
-		w.Write([]byte(`{"addresses":["tcp://192.0.2.42::22000"], "relays":[{"url": "relay://192.0.2.43:443", "latency": 42}]}`))
+		_, _ = w.Write([]byte(`{"addresses":["tcp://192.0.2.42::22000"], "relays":[{"url": "relay://192.0.2.43:443", "latency": 42}]}`))
 	}
 }
 

lib/fs/basicfs_test.go

@@ -33,7 +33,7 @@ func TestChmodFile(t *testing.T) {
 	path := filepath.Join(dir, "file")
 	defer os.RemoveAll(dir)
 
-	defer os.Chmod(path, 0666)
+	defer func() { _ = os.Chmod(path, 0666) }()
 
 	fd, err := os.Create(path)
 	if err != nil {
@@ -74,7 +74,7 @@ func TestChownFile(t *testing.T) {
 	path := filepath.Join(dir, "file")
 	defer os.RemoveAll(dir)
 
-	defer os.Chmod(path, 0666)
+	defer func() { _ = os.Chmod(path, 0666) }()
 
 	fd, err := os.Create(path)
 	if err != nil {
@@ -116,7 +116,7 @@ func TestChmodDir(t *testing.T) {
 		mode = os.FileMode(0777)
 	}
 
-	defer os.Chmod(path, mode)
+	defer func() { _ = os.Chmod(path, mode) }()
 
 	if err := os.Mkdir(path, mode); err != nil {
 		t.Error(err)
@@ -147,7 +147,7 @@ func TestChtimes(t *testing.T) {
 
 	mtime := time.Now().Add(-time.Hour)
 
-	fs.Chtimes("file", mtime, mtime)
+	_ = fs.Chtimes("file", mtime, mtime)
 
 	stat, err := os.Stat(path)
 	if err != nil {

lib/fs/basicfs_watch_test.go

@@ -98,7 +98,7 @@ func TestWatchInclude(t *testing.T) {
 
 	file := "file"
 	ignored := "ignored"
-	testFs.MkdirAll(filepath.Join(name, ignored), 0777)
+	_ = testFs.MkdirAll(filepath.Join(name, ignored), 0777)
 	included := filepath.Join(ignored, "included")
 
 	testCase := func() {
@@ -274,7 +274,7 @@ func TestWatchSymlinkedRoot(t *testing.T) {
 	if err := testFs.MkdirAll(name, 0755); err != nil {
 		panic(fmt.Sprintf("Failed to create directory %s: %s", name, err))
 	}
-	defer testFs.RemoveAll(name)
+	defer func() { _ = testFs.RemoveAll(name) }()
 
 	root := filepath.Join(name, "root")
 	if err := testFs.MkdirAll(root, 0777); err != nil {
@@ -376,7 +376,7 @@ func testScenario(t *testing.T, name string, testCase func(), expectedEvents, al
 	if err := testFs.MkdirAll(name, 0755); err != nil {
 		panic(fmt.Sprintf("Failed to create directory %s: %s", name, err))
 	}
-	defer testFs.RemoveAll(name)
+	defer func() { _ = testFs.RemoveAll(name) }()
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

lib/fs/fakefs.go

@@ -105,22 +105,22 @@ func newFakeFilesystem(root string) *fakefs {
 		for (files == 0 || createdFiles < files) && (maxsize == 0 || writtenData>>20 < int64(maxsize)) {
 			dir := filepath.Join(fmt.Sprintf("%02x", rng.Intn(255)), fmt.Sprintf("%02x", rng.Intn(255)))
 			file := fmt.Sprintf("%016x", rng.Int63())
-			fs.MkdirAll(dir, 0755)
+			_ = fs.MkdirAll(dir, 0755)
 
 			fd, _ := fs.Create(filepath.Join(dir, file))
 			createdFiles++
 
 			fsize := int64(sizeavg/2 + rng.Intn(sizeavg))
-			fd.Truncate(fsize)
+			_ = fd.Truncate(fsize)
 			writtenData += fsize
 
 			ftime := time.Unix(1000000000+rng.Int63n(10*365*86400), 0)
-			fs.Chtimes(filepath.Join(dir, file), ftime, ftime)
+			_ = fs.Chtimes(filepath.Join(dir, file), ftime, ftime)
 		}
 	}
 
 	// Also create a default folder marker for good measure
-	fs.Mkdir(".stfolder", 0700)
+	_ = fs.Mkdir(".stfolder", 0700)
 
 	fakefsFs[root] = fs
 	return fs
@@ -583,7 +583,7 @@ func (f *fakeFile) readShortAt(p []byte, offs int64) (int, error) {
 	// name.
 	if f.seed == 0 {
 		hf := fnv.New64()
-		hf.Write([]byte(f.name))
+		_, _ = hf.Write([]byte(f.name))
 		f.seed = int64(hf.Sum64())
 	}
 
@@ -601,7 +601,7 @@ func (f *fakeFile) readShortAt(p []byte, offs int64) (int, error) {
 		diff := offs - minOffs
 		if diff > 0 {
 			lr := io.LimitReader(f.rng, diff)
-			io.Copy(ioutil.Discard, lr)
+			_, _ = io.Copy(ioutil.Discard, lr)
 		}
 
 		f.offset = offs

lib/fs/fakefs_test.go

@@ -130,10 +130,10 @@ func TestFakeFSRead(t *testing.T) {
 
 	// Create
 	fd, _ := fs.Create("test")
-	fd.Truncate(3 * 1 << randomBlockShift)
+	_ = fd.Truncate(3 * 1 << randomBlockShift)
 
 	// Read
-	fd.Seek(0, 0)
+	_, _ = fd.Seek(0, 0)
 	bs0, err := ioutil.ReadAll(fd)
 	if err != nil {
 		t.Fatal(err)
@@ -143,7 +143,7 @@ func TestFakeFSRead(t *testing.T) {
 	}
 
 	// Read again, starting at an odd offset
-	fd.Seek(0, 0)
+	_, _ = fd.Seek(0, 0)
 	buf0 := make([]byte, 12345)
 	n, _ := fd.Read(buf0)
 	if n != len(buf0) {

lib/fs/mtimefs.go

@@ -53,7 +53,7 @@ func (f *MtimeFS) Chtimes(name string, atime, mtime time.Time) error {
 	}
 
 	// Do a normal Chtimes call, don't care if it succeeds or not.
-	f.chtimes(name, atime, mtime)
+	_ = f.chtimes(name, atime, mtime)
 
 	// Stat the file to see what happened. Here we *do* return an error,
 	// because it might be "does not exist" or similar.

lib/fs/mtimefs_test.go

@@ -18,10 +18,10 @@ import (
 func TestMtimeFS(t *testing.T) {
 	os.RemoveAll("testdata")
 	defer os.RemoveAll("testdata")
-	os.Mkdir("testdata", 0755)
-	ioutil.WriteFile("testdata/exists0", []byte("hello"), 0644)
-	ioutil.WriteFile("testdata/exists1", []byte("hello"), 0644)
-	ioutil.WriteFile("testdata/exists2", []byte("hello"), 0644)
+	_ = os.Mkdir("testdata", 0755)
+	_ = ioutil.WriteFile("testdata/exists0", []byte("hello"), 0644)
+	_ = ioutil.WriteFile("testdata/exists1", []byte("hello"), 0644)
+	_ = ioutil.WriteFile("testdata/exists2", []byte("hello"), 0644)
 
 	// a random time with nanosecond precision
 	testTime := time.Unix(1234567890, 123456789)
@@ -73,7 +73,7 @@ func TestMtimeFS(t *testing.T) {
 	// filesystems.
 
 	testTime = time.Now().Add(5 * time.Hour).Truncate(time.Minute)
-	os.Chtimes("testdata/exists0", testTime, testTime)
+	_ = os.Chtimes("testdata/exists0", testTime, testTime)
 	if info, err := mtimefs.Lstat("testdata/exists0"); err != nil {
 		t.Error("Lstat shouldn't fail:", err)
 	} else if !info.ModTime().Equal(testTime) {
@@ -93,8 +93,8 @@ func TestMtimeFSInsensitive(t *testing.T) {
 	theTest := func(t *testing.T, fs *MtimeFS, shouldSucceed bool) {
 		os.RemoveAll("testdata")
 		defer os.RemoveAll("testdata")
-		os.Mkdir("testdata", 0755)
-		ioutil.WriteFile("testdata/FiLe", []byte("hello"), 0644)
+		_ = os.Mkdir("testdata", 0755)
+		_ = ioutil.WriteFile("testdata/FiLe", []byte("hello"), 0644)
 
 		// a random time with nanosecond precision
 		testTime := time.Unix(1234567890, 123456789)

lib/fs/tempname.go

@@ -51,7 +51,7 @@ func TempNameWithPrefix(name, prefix string) string {
 	tbase := filepath.Base(name)
 	if len(tbase) > maxFilenameLength {
 		hash := md5.New()
-		hash.Write([]byte(name))
+		_, _ = hash.Write([]byte(name))
 		tbase = fmt.Sprintf("%x", hash.Sum(nil))
 	}
 	tname := fmt.Sprintf("%s%s.tmp", prefix, tbase)

lib/ignore/ignore.go

@@ -136,7 +136,7 @@ func (m *Matcher) Load(file string) error {
 
 	fd, info, err := loadIgnoreFile(m.fs, file, m.changeDetector)
 	if err != nil {
-		m.parseLocked(&bytes.Buffer{}, file)
+		_ = m.parseLocked(&bytes.Buffer{}, file)
 		return err
 	}
 	defer fd.Close()
@@ -310,8 +310,8 @@ func (m *Matcher) SkipIgnoredDirs() bool {
 func hashPatterns(patterns []Pattern) string {
 	h := md5.New()
 	for _, pat := range patterns {
-		h.Write([]byte(pat.String()))
-		h.Write([]byte("\n"))
+		_, _ = h.Write([]byte(pat.String()))
+		_, _ = h.Write([]byte("\n"))
 	}
 	return fmt.Sprintf("%x", h.Sum(nil))
 }
@@ -505,7 +505,7 @@ func WriteIgnores(filesystem fs.Filesystem, path string, content []string) error
 	if err := fd.Close(); err != nil {
 		return err
 	}
-	filesystem.Hide(path)
+	_ = filesystem.Hide(path)
 
 	return nil
 }

lib/ignore/ignore_test.go

@@ -246,15 +246,15 @@ func TestCaching(t *testing.T) {
 
 	defer fd1.Close()
 	defer fd2.Close()
-	defer fs.Remove(fd1.Name())
-	defer fs.Remove(fd2.Name())
+	defer func() { _ = fs.Remove(fd1.Name()) }()
+	defer func() { _ = fs.Remove(fd2.Name()) }()
 
 	_, err = fd1.Write([]byte("/x/\n#include " + filepath.Base(fd2.Name()) + "\n"))
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	fd2.Write([]byte("/y/\n"))
+	_, _ = fd2.Write([]byte("/y/\n"))
 
 	pats := New(fs, WithCache(true))
 	err = pats.Load(fd1.Name())
@@ -289,10 +289,10 @@ func TestCaching(t *testing.T) {
 	// Modify the include file, expect empty cache. Ensure the timestamp on
 	// the file changes.
 
-	fd2.Write([]byte("/z/\n"))
-	fd2.Sync()
+	_, _ = fd2.Write([]byte("/z/\n"))
+	_ = fd2.Sync()
 	fakeTime := time.Now().Add(5 * time.Second)
-	fs.Chtimes(fd2.Name(), fakeTime, fakeTime)
+	_ = fs.Chtimes(fd2.Name(), fakeTime, fakeTime)
 
 	err = pats.Load(fd1.Name())
 	if err != nil {
@@ -321,10 +321,10 @@ func TestCaching(t *testing.T) {
 
 	// Modify the root file, expect cache to be invalidated
 
-	fd1.Write([]byte("/a/\n"))
-	fd1.Sync()
+	_, _ = fd1.Write([]byte("/a/\n"))
+	_ = fd1.Sync()
 	fakeTime = time.Now().Add(5 * time.Second)
-	fs.Chtimes(fd1.Name(), fakeTime, fakeTime)
+	_ = fs.Chtimes(fd1.Name(), fakeTime, fakeTime)
 
 	err = pats.Load(fd1.Name())
 	if err != nil {
@@ -434,7 +434,7 @@ flamingo
 
 	_, err = fd.Write([]byte(stignore))
 	defer fd.Close()
-	defer fs.Remove(fd.Name())
+	defer func() { _ = fs.Remove(fd.Name()) }()
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -474,7 +474,7 @@ func TestCacheReload(t *testing.T) {
 	}
 
 	defer fd.Close()
-	defer fs.Remove(fd.Name())
+	defer func() { _ = fs.Remove(fd.Name()) }()
 
 	// Ignore file matches f1 and f2
 
@@ -515,9 +515,9 @@ func TestCacheReload(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	fd.Sync()
+	_ = fd.Sync()
 	fakeTime := time.Now().Add(5 * time.Second)
-	fs.Chtimes(fd.Name(), fakeTime, fakeTime)
+	_ = fs.Chtimes(fd.Name(), fakeTime, fakeTime)
 
 	err = pats.Load(fd.Name())
 	if err != nil {
@@ -605,7 +605,7 @@ func TestHashOfEmpty(t *testing.T) {
 	// recalculate the hash. d41d8cd98f00b204e9800998ecf8427e is the md5 of
 	// nothing.
 
-	p1.Load("file/does/not/exist")
+	_ = p1.Load("file/does/not/exist")
 	secondHash := p1.Hash()
 
 	if firstHash == secondHash {

lib/logger/logger.go

@@ -120,7 +120,7 @@ func (l *logger) debugln(level int, vals ...interface{}) {
 	s := fmt.Sprintln(vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(level, "DEBUG: "+s)
+	_ = l.logger.Output(level, "DEBUG: "+s)
 	l.callHandlers(LevelDebug, s)
 }
 
@@ -132,7 +132,7 @@ func (l *logger) debugf(level int, format string, vals ...interface{}) {
 	s := fmt.Sprintf(format, vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(level, "DEBUG: "+s)
+	_ = l.logger.Output(level, "DEBUG: "+s)
 	l.callHandlers(LevelDebug, s)
 }
 
@@ -141,7 +141,7 @@ func (l *logger) Verboseln(vals ...interface{}) {
 	s := fmt.Sprintln(vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "VERBOSE: "+s)
+	_ = l.logger.Output(2, "VERBOSE: "+s)
 	l.callHandlers(LevelVerbose, s)
 }
 
@@ -150,7 +150,7 @@ func (l *logger) Verbosef(format string, vals ...interface{}) {
 	s := fmt.Sprintf(format, vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "VERBOSE: "+s)
+	_ = l.logger.Output(2, "VERBOSE: "+s)
 	l.callHandlers(LevelVerbose, s)
 }
 
@@ -159,7 +159,7 @@ func (l *logger) Infoln(vals ...interface{}) {
 	s := fmt.Sprintln(vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "INFO: "+s)
+	_ = l.logger.Output(2, "INFO: "+s)
 	l.callHandlers(LevelInfo, s)
 }
 
@@ -168,7 +168,7 @@ func (l *logger) Infof(format string, vals ...interface{}) {
 	s := fmt.Sprintf(format, vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "INFO: "+s)
+	_ = l.logger.Output(2, "INFO: "+s)
 	l.callHandlers(LevelInfo, s)
 }
 
@@ -177,7 +177,7 @@ func (l *logger) Warnln(vals ...interface{}) {
 	s := fmt.Sprintln(vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "WARNING: "+s)
+	_ = l.logger.Output(2, "WARNING: "+s)
 	l.callHandlers(LevelWarn, s)
 }
 
@@ -186,7 +186,7 @@ func (l *logger) Warnf(format string, vals ...interface{}) {
 	s := fmt.Sprintf(format, vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "WARNING: "+s)
+	_ = l.logger.Output(2, "WARNING: "+s)
 	l.callHandlers(LevelWarn, s)
 }
 
@@ -196,7 +196,7 @@ func (l *logger) Fatalln(vals ...interface{}) {
 	s := fmt.Sprintln(vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "FATAL: "+s)
+	_ = l.logger.Output(2, "FATAL: "+s)
 	l.callHandlers(LevelFatal, s)
 	os.Exit(1)
 }
@@ -207,7 +207,7 @@ func (l *logger) Fatalf(format string, vals ...interface{}) {
 	s := fmt.Sprintf(format, vals...)
 	l.mut.Lock()
 	defer l.mut.Unlock()
-	l.logger.Output(2, "FATAL: "+s)
+	_ = l.logger.Output(2, "FATAL: "+s)
 	l.callHandlers(LevelFatal, s)
 	os.Exit(1)
 }