build: update linter to v2

accounts/abi/bind/bind.go

@@ -129,7 +129,7 @@ func Bind(types []string, abis []string, bytecodes []string, pkg string, lang La
 		return string(code), nil
 	}
 	// For all others just return as is for now
-	return string(buffer.Bytes()), nil
+	return buffer.String(), nil
 }
 
 // bindType is a set of type binders that convert Solidity types to some supported

accounts/abi/unpack_test.go

@@ -368,11 +368,11 @@ func TestUnmarshal(t *testing.T) {
 	if err != nil {
 		t.Error(err)
 	} else {
-		if bytes.Compare(p0, p0Exp) != 0 {
+		if !bytes.Equal(p0, p0Exp) {
 			t.Errorf("unexpected value unpacked: want %x, got %x", p0Exp, p0)
 		}
 
-		if bytes.Compare(p1[:], p1Exp) != 0 {
+		if !bytes.Equal(p1[:], p1Exp) {
 			t.Errorf("unexpected value unpacked: want %x, got %x", p1Exp, p1)
 		}
 	}

bmt/bmt.go

@@ -260,8 +260,7 @@ func NewTree(hasher BaseHasher, segmentSize, segmentCount int) *Tree {
 	for d := 1; d <= depth(segmentCount); d++ {
 		nodes := make([]*Node, count)
 		for i := 0; i < len(nodes); i++ {
-			var parent *Node
-			parent = prevlevel[i/2]
+			parent := prevlevel[i/2]
 			t := NewNode(level, i, parent)
 			nodes[i] = t
 		}

build/ci.go

@@ -319,8 +319,8 @@ func doLint(cmdline []string) {
 		packages = flag.CommandLine.Args()
 	}
 	// Get metalinter and install all supported linters
-	build.MustRun(goTool("get", "gopkg.in/alecthomas/gometalinter.v1"))
-	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v1"), "--install")
+	build.MustRun(goTool("get", "gopkg.in/alecthomas/gometalinter.v2"))
+	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v2"), "--install")
 
 	// Run fast linters batched together
 	configs := []string{
@@ -332,12 +332,12 @@ func doLint(cmdline []string) {
 		"--enable=goconst",
 		"--min-occurrences=6", // for goconst
 	}
-	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v1"), append(configs, packages...)...)
+	build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v2"), append(configs, packages...)...)
 
 	// Run slow linters one by one
 	for _, linter := range []string{"unconvert", "gosimple"} {
 		configs = []string{"--vendor", "--deadline=10m", "--disable-all", "--enable=" + linter}
-		build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v1"), append(configs, packages...)...)
+		build.MustRunCommand(filepath.Join(GOBIN, "gometalinter.v2"), append(configs, packages...)...)
 	}
 }
 

cmd/faucet/faucet.go

@@ -506,7 +506,7 @@ func (f *faucet) apiHandler(conn *websocket.Conn) {
 
 		// Send an error if too frequent funding, othewise a success
 		if !fund {
-			if err = sendError(conn, fmt.Errorf("%s left until next allowance", common.PrettyDuration(timeout.Sub(time.Now())))); err != nil {
+			if err = sendError(conn, fmt.Errorf("%s left until next allowance", common.PrettyDuration(timeout.Sub(time.Now())))); err != nil { // nolint: gosimple
 				log.Warn("Failed to send funding error to client", "err", err)
 				return
 			}

cmd/swarm/config.go

@@ -267,7 +267,7 @@ func envVarsOverride(currentConfig *bzzapi.Config) (config *bzzapi.Config) {
 	}
 
 	//EnsApi can be set to "", so can't check for empty string, as it is allowed
-	if ensapi, exists := os.LookupEnv(SWARM_ENV_ENS_API); exists == true {
+	if ensapi, exists := os.LookupEnv(SWARM_ENV_ENS_API); exists {
 		currentConfig.EnsApi = ensapi
 	}
 

cmd/swarm/config_test.go

@@ -124,7 +124,7 @@ func TestCmdLineOverrides(t *testing.T) {
 		t.Fatalf("Expected network ID to be %d, got %d", 42, info.NetworkId)
 	}
 
-	if info.SyncEnabled != true {
+	if !info.SyncEnabled {
 		t.Fatal("Expected Sync to be enabled, but is false")
 	}
 
@@ -219,7 +219,7 @@ func TestFileOverrides(t *testing.T) {
 		t.Fatalf("Expected network ID to be %d, got %d", 54, info.NetworkId)
 	}
 
-	if info.SyncEnabled != true {
+	if !info.SyncEnabled {
 		t.Fatal("Expected Sync to be enabled, but is false")
 	}
 
@@ -334,7 +334,7 @@ func TestEnvVars(t *testing.T) {
 		t.Fatalf("Expected Cors flag to be set to %s, got %s", "*", info.Cors)
 	}
 
-	if info.SyncEnabled != true {
+	if !info.SyncEnabled {
 		t.Fatal("Expected Sync to be enabled, but is false")
 	}
 
@@ -431,7 +431,7 @@ func TestCmdLineOverridesFile(t *testing.T) {
 		t.Fatalf("Expected network ID to be %d, got %d", expectNetworkId, info.NetworkId)
 	}
 
-	if info.SyncEnabled != true {
+	if !info.SyncEnabled {
 		t.Fatal("Expected Sync to be enabled, but is false")
 	}
 

consensus/clique/clique.go

@@ -630,7 +630,7 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 		}
 	}
 	// Sweet, the protocol permits us to sign the block, wait for our time
-	delay := time.Unix(header.Time.Int64(), 0).Sub(time.Now())
+	delay := time.Unix(header.Time.Int64(), 0).Sub(time.Now()) // nolint: gosimple
 	if header.Difficulty.Cmp(diffNoTurn) == 0 {
 		// It's not our turn explicitly to sign, delay it a bit
 		wiggle := time.Duration(len(snap.Signers)/2+1) * wiggleTime

console/console_test.go

@@ -164,7 +164,7 @@ func TestWelcome(t *testing.T) {
 
 	tester.console.Welcome()
 
-	output := string(tester.output.Bytes())
+	output := tester.output.String()
 	if want := "Welcome"; !strings.Contains(output, want) {
 		t.Fatalf("console output missing welcome message: have\n%s\nwant also %s", output, want)
 	}
@@ -188,7 +188,7 @@ func TestEvaluate(t *testing.T) {
 	defer tester.Close(t)
 
 	tester.console.Evaluate("2 + 2")
-	if output := string(tester.output.Bytes()); !strings.Contains(output, "4") {
+	if output := tester.output.String(); !strings.Contains(output, "4") {
 		t.Fatalf("statement evaluation failed: have %s, want %s", output, "4")
 	}
 }
@@ -218,7 +218,7 @@ func TestInteractive(t *testing.T) {
 	case <-time.After(time.Second):
 		t.Fatalf("secondary prompt timeout")
 	}
-	if output := string(tester.output.Bytes()); !strings.Contains(output, "4") {
+	if output := tester.output.String(); !strings.Contains(output, "4") {
 		t.Fatalf("statement evaluation failed: have %s, want %s", output, "4")
 	}
 }
@@ -230,7 +230,7 @@ func TestPreload(t *testing.T) {
 	defer tester.Close(t)
 
 	tester.console.Evaluate("preloaded")
-	if output := string(tester.output.Bytes()); !strings.Contains(output, "some-preloaded-string") {
+	if output := tester.output.String(); !strings.Contains(output, "some-preloaded-string") {
 		t.Fatalf("preloaded variable missing: have %s, want %s", output, "some-preloaded-string")
 	}
 }
@@ -243,7 +243,7 @@ func TestExecute(t *testing.T) {
 	tester.console.Execute("exec.js")
 
 	tester.console.Evaluate("execed")
-	if output := string(tester.output.Bytes()); !strings.Contains(output, "some-executed-string") {
+	if output := tester.output.String(); !strings.Contains(output, "some-executed-string") {
 		t.Fatalf("execed variable missing: have %s, want %s", output, "some-executed-string")
 	}
 }
@@ -275,7 +275,7 @@ func TestPrettyPrint(t *testing.T) {
   string: ` + two + `
 }
 `
-	if output := string(tester.output.Bytes()); output != want {
+	if output := tester.output.String(); output != want {
 		t.Fatalf("pretty print mismatch: have %s, want %s", output, want)
 	}
 }
@@ -287,7 +287,7 @@ func TestPrettyError(t *testing.T) {
 	tester.console.Evaluate("throw 'hello'")
 
 	want := jsre.ErrorColor("hello") + "\n"
-	if output := string(tester.output.Bytes()); output != want {
+	if output := tester.output.String(); output != want {
 		t.Fatalf("pretty error mismatch: have %s, want %s", output, want)
 	}
 }

core/asm/asm.go

@@ -114,10 +114,7 @@ func PrintDisassembled(code string) error {
 			fmt.Printf("%06v: %v\n", it.PC(), it.Op())
 		}
 	}
-	if err := it.Error(); err != nil {
-		return err
-	}
-	return nil
+	return it.Error()
 }
 
 // Return all disassembled EVM instructions in human-readable format.

core/asm/compiler.go

@@ -237,10 +237,7 @@ func (c *Compiler) pushBin(v interface{}) {
 // isPush returns whether the string op is either any of
 // push(N).
 func isPush(op string) bool {
-	if op == "push" {
-		return true
-	}
-	return false
+	return op == "push"
 }
 
 // isJump returns whether the string op is jump(i)

ethstats/ethstats.go

@@ -193,7 +193,6 @@ func (s *Service) loop() {
 			}
 		}
 		close(quitCh)
-		return
 	}()
 	// Loop reporting until termination
 	for {

p2p/discv5/net.go

@@ -684,7 +684,7 @@ func (net *Network) refresh(done chan<- struct{}) {
 		seeds = net.nursery
 	}
 	if len(seeds) == 0 {
-		log.Trace(fmt.Sprint("no seed nodes found"))
+		log.Trace("no seed nodes found")
 		close(done)
 		return
 	}

p2p/discv5/ntp.go

@@ -54,10 +54,10 @@ func checkClockDrift() {
 		howtofix := fmt.Sprintf("Please enable network time synchronisation in system settings")
 		separator := strings.Repeat("-", len(warning))
 
-		log.Warn(fmt.Sprint(separator))
-		log.Warn(fmt.Sprint(warning))
-		log.Warn(fmt.Sprint(howtofix))
-		log.Warn(fmt.Sprint(separator))
+		log.Warn(separator)
+		log.Warn(warning)
+		log.Warn(howtofix)
+		log.Warn(separator)
 	} else {
 		log.Debug(fmt.Sprintf("Sanity NTP check reported %v drift, all ok", drift))
 	}

p2p/discv5/ticket.go

@@ -398,12 +398,12 @@ func (s *ticketStore) nextRegisterableTicket() (t *ticketRef, wait time.Duration
 			//s.removeExcessTickets(topic)
 			if len(tickets.buckets) != 0 {
 				empty = false
-				if list := tickets.buckets[bucket]; list != nil {
-					for _, ref := range list {
-						//debugLog(fmt.Sprintf(" nrt bucket = %d node = %x sn = %v wait = %v", bucket, ref.t.node.ID[:8], ref.t.serial, time.Duration(ref.topicRegTime()-now)))
-						if nextTicket.t == nil || ref.topicRegTime() < nextTicket.topicRegTime() {
-							nextTicket = ref
-						}
+
+				list := tickets.buckets[bucket]
+				for _, ref := range list {
+					//debugLog(fmt.Sprintf(" nrt bucket = %d node = %x sn = %v wait = %v", bucket, ref.t.node.ID[:8], ref.t.serial, time.Duration(ref.topicRegTime()-now)))
+					if nextTicket.t == nil || ref.topicRegTime() < nextTicket.topicRegTime() {
+						nextTicket = ref
 					}
 				}
 			}

p2p/simulations/network.go

@@ -403,9 +403,8 @@ func (self *Network) getNodeByName(name string) *Node {
 func (self *Network) GetNodes() (nodes []*Node) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
-	for _, node := range self.Nodes {
-		nodes = append(nodes, node)
-	}
+
+	nodes = append(nodes, self.Nodes...)
 	return nodes
 }
 
@@ -477,7 +476,7 @@ func (self *Network) InitConn(oneID, otherID discover.NodeID) (*Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-	if time.Now().Sub(conn.initiated) < dialBanTimeout {
+	if time.Since(conn.initiated) < dialBanTimeout {
 		return nil, fmt.Errorf("connection between %v and %v recently attempted", oneID, otherID)
 	}
 	if conn.Up {

rpc/http_test.go

@@ -32,7 +32,7 @@ func TestHTTPErrorResponseWithPut(t *testing.T) {
 }
 
 func TestHTTPErrorResponseWithMaxContentLength(t *testing.T) {
-	body := make([]rune, maxHTTPRequestContentLength+1, maxHTTPRequestContentLength+1)
+	body := make([]rune, maxHTTPRequestContentLength+1)
 	testHTTPErrorResponse(t,
 		"POST", contentType, string(body), http.StatusRequestEntityTooLarge)
 }

swarm/api/config_test.go

@@ -36,7 +36,7 @@ func TestConfig(t *testing.T) {
 	one := NewDefaultConfig()
 	two := NewDefaultConfig()
 
-	if equal := reflect.DeepEqual(one, two); equal == false {
+	if equal := reflect.DeepEqual(one, two); !equal {
 		t.Fatal("Two default configs are not equal")
 	}
 

swarm/fuse/swarmfs_test.go

@@ -95,7 +95,7 @@ func mountDir(t *testing.T, api *api.Api, files map[string]fileInfo, bzzHash str
 	}
 
 	// Test listMounts
-	if found == false {
+	if !found {
 		t.Fatalf("Error getting mounts information for %v: %v", mountDir, err)
 	}
 
@@ -185,10 +185,8 @@ func isDirEmpty(name string) bool {
 	defer f.Close()
 
 	_, err = f.Readdirnames(1)
-	if err == io.EOF {
-		return true
-	}
-	return false
+
+	return err == io.EOF
 }
 
 type testAPI struct {
@@ -388,7 +386,7 @@ func (ta *testAPI) seekInMultiChunkFile(t *testing.T) {
 	d.Read(contents)
 	finfo := files["1.txt"]
 
-	if bytes.Compare(finfo.contents[:6024][5000:], contents) != 0 {
+	if !bytes.Equal(finfo.contents[:6024][5000:], contents) {
 		t.Fatalf("File seek contents mismatch")
 	}
 	d.Close()

swarm/storage/chunker_test.go

@@ -77,7 +77,7 @@ func (self *chunkerTester) Split(chunker Splitter, data io.Reader, size int64, c
 
 	key, err = chunker.Split(data, size, chunkC, swg, nil)
 	if err != nil && expectedError == nil {
-		err = errors.New(fmt.Sprintf("Split error: %v", err))
+		err = fmt.Errorf("Split error: %v", err)
 	}
 
 	if chunkC != nil {
@@ -123,7 +123,7 @@ func (self *chunkerTester) Append(chunker Splitter, rootKey Key, data io.Reader,
 
 	key, err = chunker.Append(rootKey, data, chunkC, swg, nil)
 	if err != nil && expectedError == nil {
-		err = errors.New(fmt.Sprintf("Append error: %v", err))
+		err = fmt.Errorf("Append error: %v", err)
 	}
 
 	if chunkC != nil {