Fix typos and warnings for GoReport / GolangCiLinter (#132)

- typos
- gofmt -s
- govet warnings
- golangci-lint run

config/config.go

@@ -111,7 +111,7 @@ func Load(path string, netMode NetMode) (Config, error) {
 		ApplicationConfiguration: ApplicationConfiguration{},
 	}
 
-	err = yaml.Unmarshal([]byte(configData), &config)
+	err = yaml.Unmarshal(configData, &config)
 	if err != nil {
 		return Config{}, errors.Wrap(err, "Problem unmarshaling config json data")
 	}

pkg/core/asset_state.go

@@ -29,7 +29,7 @@ func (a Assets) commit(b storage.Batch) error {
 	return nil
 }
 
-// AssetState represents the state of an NEO registerd Asset.
+// AssetState represents the state of an NEO registered Asset.
 type AssetState struct {
 	ID         util.Uint256
 	AssetType  transaction.AssetType

pkg/core/blockchain.go

@@ -510,7 +510,7 @@ func (bc *Blockchain) HasBlock(hash util.Uint256) bool {
 	return false
 }
 
-// CurrentBlockHash returns the heighest processed block hash.
+// CurrentBlockHash returns the highest processed block hash.
 func (bc *Blockchain) CurrentBlockHash() (hash util.Uint256) {
 	bc.headersOp <- func(headerList *HeaderHashList) {
 		hash = headerList.Get(int(bc.BlockHeight()))
@@ -553,8 +553,7 @@ func (bc *Blockchain) GetAssetState(assetID util.Uint256) *AssetState {
 	var as *AssetState
 	bc.Store.Seek(storage.STAsset.Bytes(), func(k, v []byte) {
 		var a AssetState
-		a.DecodeBinary(bytes.NewReader(v))
+		if err := a.DecodeBinary(bytes.NewReader(v)); err == nil && a.ID == assetID {
-		if a.ID == assetID {
 			as = &a
 		}
 	})

pkg/core/header_test.go

@@ -52,10 +52,10 @@ func TestHeaderEncodeDecode(t *testing.T) {
 	if !header.NextConsensus.Equals(headerDecode.NextConsensus) {
 		t.Fatalf("expected both next consensus fields to be equal")
 	}
-	if bytes.Compare(header.Script.InvocationScript, headerDecode.Script.InvocationScript) != 0 {
+	if !bytes.Equal(header.Script.InvocationScript, headerDecode.Script.InvocationScript) {
 		t.Fatalf("expected equal invocation scripts %v and %v", header.Script.InvocationScript, headerDecode.Script.InvocationScript)
 	}
-	if bytes.Compare(header.Script.VerificationScript, headerDecode.Script.VerificationScript) != 0 {
+	if !bytes.Equal(header.Script.VerificationScript, headerDecode.Script.VerificationScript) {
 		t.Fatalf("expected equal verification scripts %v and %v", header.Script.VerificationScript, headerDecode.Script.VerificationScript)
 	}
 }

pkg/core/storage/helpers.go

@@ -73,10 +73,7 @@ func HeaderHashes(s Store) ([]util.Uint256, error) {
 	sort.Sort(uint32Slice(sortedKeys))
 
 	for _, key := range sortedKeys {
-		values := hashMap[key]
+		hashes = append(hashes, hashMap[key]...)
-		for _, hash := range values {
-			hashes = append(hashes, hash)
-		}
 	}
 
 	return hashes, nil

pkg/core/storage/memory_store.go

@@ -41,13 +41,13 @@ func (s *MemoryStore) Get(key []byte) ([]byte, error) {
 	return nil, ErrKeyNotFound
 }
 
-// Put implementes the Store interface.
+// Put implements the Store interface.
 func (s *MemoryStore) Put(key, value []byte) error {
 	s.mem[makeKey(key)] = value
 	return nil
 }
 
-// PutBatch implementes the Store interface.
+// PutBatch implements the Store interface.
 func (s *MemoryStore) PutBatch(batch Batch) error {
 	b := batch.(*MemoryBatch)
 	for k, v := range b.m {
@@ -58,7 +58,7 @@ func (s *MemoryStore) PutBatch(batch Batch) error {
 	return nil
 }
 
-// Seek implementes the Store interface.
+// Seek implements the Store interface.
 func (s *MemoryStore) Seek(key []byte, f func(k, v []byte)) {
 }
 

pkg/crypto/base58.go

@@ -57,7 +57,7 @@ func Base58Decode(s string) ([]byte, error) {
 
 	out := n.Bytes()
 	buf := make([]byte, zero+len(out))
-	copy(buf[zero:], out[:])
+	copy(buf[zero:], out)
 
 	return buf, nil
 }
@@ -100,14 +100,18 @@ func Base58CheckDecode(s string) (b []byte, err error) {
 	}
 
 	sha := sha256.New()
-	sha.Write(b[:len(b)-4])
+	if _, err = sha.Write(b[:len(b)-4]); err != nil {
+		return nil, err
+	}
 	hash := sha.Sum(nil)
 
 	sha.Reset()
-	sha.Write(hash)
+	if _, err = sha.Write(hash); err != nil {
+		return nil, err
+	}
 	hash = sha.Sum(nil)
 
-	if bytes.Compare(hash[0:4], b[len(b)-4:]) != 0 {
+	if !bytes.Equal(hash[0:4], b[len(b)-4:]) {
 		return nil, errors.New("invalid base-58 check string: invalid checksum.")
 	}
 

pkg/crypto/elliptic_curve.go

@@ -167,10 +167,7 @@ func (c *EllipticCurve) IsOnCurve(P ECPoint) bool {
 			mulMod(c.A, P.X, c.P), c.P),
 		c.B, c.P)
 
-	if lhs.Cmp(rhs) == 0 {
+	return lhs.Cmp(rhs) == 0
-		return true
-	}
-	return false
 }
 
 // Add computes R = P + Q on EllipticCurve ec.

pkg/network/discovery.go

@@ -80,7 +80,7 @@ func (d *DefaultDiscovery) RegisterBadAddr(addr string) {
 
 // UnconnectedPeers returns all addresses of unconnected addrs.
 func (d *DefaultDiscovery) UnconnectedPeers() []string {
-	var addrs []string
+	addrs := make([]string, 0, len(d.unconnectedAddrs))
 	for addr := range d.unconnectedAddrs {
 		addrs = append(addrs, addr)
 	}
@@ -89,7 +89,7 @@ func (d *DefaultDiscovery) UnconnectedPeers() []string {
 
 // BadPeers returns all addresses of bad addrs.
 func (d *DefaultDiscovery) BadPeers() []string {
-	var addrs []string
+	addrs := make([]string, 0, len(d.badAddrs))
 	for addr := range d.badAddrs {
 		addrs = append(addrs, addr)
 	}

pkg/network/server.go

@@ -56,7 +56,7 @@ type (
 )
 
 // NewServer returns a new Server, initialized with the given configuration.
-func NewServer(config ServerConfig, chain *core.Blockchain) *Server {
+func NewServer(config ServerConfig, chain core.Blockchainer) *Server {
 	s := &Server{
 		ServerConfig: config,
 		chain:        chain,
@@ -129,7 +129,11 @@ func (s *Server) run() {
 			return
 		case p := <-s.register:
 			// When a new peer is connected we send out our version immediately.
-			s.sendVersion(p)
+			if err := s.sendVersion(p); err != nil {
+				log.WithFields(log.Fields{
+					"endpoint": p.Endpoint(),
+				}).Error(err)
+			}
 			s.peers[p] = true
 			log.WithFields(log.Fields{
 				"endpoint": p.Endpoint(),
@@ -258,9 +262,9 @@ func (s *Server) requestHeaders(p Peer) {
 // send at once.
 func (s *Server) requestBlocks(p Peer) {
 	var (
+		hashes       []util.Uint256
 		hashStart    = s.chain.BlockHeight() + 1
 		headerHeight = s.chain.HeaderHeight()
-		hashes       = []util.Uint256{}
 	)
 	for hashStart < headerHeight && len(hashes) < maxBlockBatch {
 		hash := s.chain.GetHeaderHash(int(hashStart))

pkg/network/server_config.go

@@ -26,7 +26,7 @@ type (
 		// ModeMainNet NEO main network.
 		Net config.NetMode
 
-		// Relay determins whether the server is forwarding its inventory.
+		// Relay determines whether the server is forwarding its inventory.
 		Relay bool
 
 		// Seeds are a list of initial nodes used to establish connectivity.

pkg/rpc/README.md

@@ -66,7 +66,7 @@ The server is written to support as much of the [JSON-RPC 2.0 Spec](http://www.j
 An example would be viewing the version of the node:
 
 ```bash
-curl -X POST -d '{"jsonrpc": "2.0", "method": "getversion", "params": [], "id": 1}" http://localhost:20332
+$ curl -X POST -d '{"jsonrpc": "2.0", "method": "getversion", "params": [], "id": 1}' http://localhost:20332
 ```
 
 which would yield the response:

pkg/rpc/server_test.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"strconv"
+	"strings"
 	"testing"
 
 	"github.com/CityOfZion/neo-go/config"
@@ -108,9 +109,7 @@ func TestHandler(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(fmt.Sprintf("method: %s, rpc call: %s", tc.method, tc.rpcCall), func(t *testing.T) {
 
-			jsonStr := []byte(tc.rpcCall)
+			req := httptest.NewRequest("POST", "http://0.0.0.0:20333/", strings.NewReader(tc.rpcCall))
-
-			req := httptest.NewRequest("POST", "http://0.0.0.0:20333/", bytes.NewBuffer(jsonStr))
 			req.Header.Set("Content-Type", "application/json")
 
 			w := httptest.NewRecorder()

pkg/util/array_test.go

@@ -14,7 +14,7 @@ func TestArrayReverse(t *testing.T) {
 	}
 }
 
-// This tests a bug that occured with arrays of size 1
+// This tests a bug that occurred with arrays of size 1
 func TestArrayReverseLen2(t *testing.T) {
 	arr := []byte{0x01}
 	have := ArrayReverse(arr)

pkg/util/endpoint.go

@@ -43,7 +43,7 @@ func (e Endpoint) Network() string { return "tcp" }
 func (e Endpoint) String() string {
 	b := make([]uint8, 4)
 	for i := 0; i < 4; i++ {
-		b[i] = byte(e.IP[len(e.IP)-4+i])
+		b[i] = e.IP[len(e.IP)-4+i]
 	}
 	return fmt.Sprintf("%d.%d.%d.%d:%d", b[0], b[1], b[2], b[3], e.Port)
 }

pkg/vm/cli/cli.go

@@ -230,7 +230,7 @@ func parseArgs(args []string) ([]vm.StackItem, error) {
 func printHelp() {
 	names := make([]string, len(commands))
 	i := 0
-	for name, _ := range commands {
+	for name := range commands {
 		names[i] = name
 		i++
 	}

pkg/vm/compiler/analysis.go

@@ -54,7 +54,7 @@ func typeAndValueForField(fld *types.Var) types.TypeAndValue {
 
 // countGlobals counts the global variables in the program to add
 // them with the stacksize of the function.
-func countGlobals(f *ast.File) (i int64) {
+func countGlobals(f ast.Node) (i int64) {
 	ast.Inspect(f, func(node ast.Node) bool {
 		switch node.(type) {
 		// Skip all functio declarations.
@@ -78,11 +78,12 @@ func isIdentBool(ident *ast.Ident) bool {
 // makeBoolFromIdent creates a bool type from an *ast.Ident.
 func makeBoolFromIdent(ident *ast.Ident, tinfo *types.Info) types.TypeAndValue {
 	var b bool
-	if ident.Name == "true" {
+	switch ident.Name {
+	case "true":
 		b = true
-	} else if ident.Name == "false" {
+	case "false":
 		b = false
-	} else {
+	default:
 		log.Fatalf("givent identifier cannot be converted to a boolean => %s", ident.Name)
 	}
 	return types.TypeAndValue{
@@ -132,7 +133,7 @@ func (f funcUsage) funcUsed(name string) bool {
 }
 
 // hasReturnStmt look if the given FuncDecl has a return statement.
-func hasReturnStmt(decl *ast.FuncDecl) (b bool) {
+func hasReturnStmt(decl ast.Node) (b bool) {
 	ast.Inspect(decl, func(node ast.Node) bool {
 		if _, ok := node.(*ast.ReturnStmt); ok {
 			b = true

pkg/vm/compiler/codegen.go

@@ -124,7 +124,7 @@ func (c *codegen) emitStoreStructField(i int) {
 // convertGlobals will traverse the AST and only convert global declarations.
 // If we call this in convertFuncDecl then it will load all global variables
 // into the scope of the function.
-func (c *codegen) convertGlobals(f *ast.File) {
+func (c *codegen) convertGlobals(f ast.Node) {
 	ast.Inspect(f, func(node ast.Node) bool {
 		switch n := node.(type) {
 		case *ast.FuncDecl:
@@ -136,7 +136,7 @@ func (c *codegen) convertGlobals(f *ast.File) {
 	})
 }
 
-func (c *codegen) convertFuncDecl(file *ast.File, decl *ast.FuncDecl) {
+func (c *codegen) convertFuncDecl(file ast.Node, decl *ast.FuncDecl) {
 	var (
 		f  *funcScope
 		ok bool
@@ -428,13 +428,14 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		emitOpcode(c.prog, vm.Onop)
 
 		// Check builtin first to avoid nil pointer on funcScope!
-		if isBuiltin {
+		switch {
+		case isBuiltin:
 			// Use the ident to check, builtins are not in func scopes.
 			// We can be sure builtins are of type *ast.Ident.
 			c.convertBuiltin(n)
-		} else if isSyscall(f.name) {
+		case isSyscall(f.name):
 			c.convertSyscall(f.name)
-		} else {
+		default:
 			emitCall(c.prog, vm.Ocall, int16(f.label))
 		}
 

pkg/vm/compiler/emit.go

@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"io"
 	"math/big"
 
 	"github.com/CityOfZion/neo-go/pkg/util"
@@ -19,11 +20,11 @@ func emit(w *bytes.Buffer, op vm.Opcode, b []byte) error {
 	return err
 }
 
-func emitOpcode(w *bytes.Buffer, op vm.Opcode) error {
+func emitOpcode(w io.ByteWriter, op vm.Opcode) error {
 	return w.WriteByte(byte(op))
 }
 
-func emitBool(w *bytes.Buffer, ok bool) error {
+func emitBool(w io.ByteWriter, ok bool) error {
 	if ok {
 		return emitOpcode(w, vm.Opusht)
 	}
@@ -57,15 +58,16 @@ func emitBytes(w *bytes.Buffer, b []byte) error {
 		n   = len(b)
 	)
 
-	if n <= int(vm.Opushbytes75) {
+	switch {
+	case n <= int(vm.Opushbytes75):
 		return emit(w, vm.Opcode(n), b)
-	} else if n < 0x100 {
+	case n < 0x100:
 		err = emit(w, vm.Opushdata1, []byte{byte(n)})
-	} else if n < 0x10000 {
+	case n < 0x10000:
 		buf := make([]byte, 2)
 		binary.LittleEndian.PutUint16(buf, uint16(n))
 		err = emit(w, vm.Opushdata2, buf)
-	} else {
+	default:
 		buf := make([]byte, 4)
 		binary.LittleEndian.PutUint32(buf, uint32(n))
 		err = emit(w, vm.Opushdata4, buf)

pkg/vm/emit.go

@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"io"
 	"math/big"
 
 	"github.com/CityOfZion/neo-go/pkg/util"
@@ -20,12 +21,12 @@ func Emit(w *bytes.Buffer, op Opcode, b []byte) error {
 }
 
 // EmitOpcode emits a single VM Opcode the given buffer.
-func EmitOpcode(w *bytes.Buffer, op Opcode) error {
+func EmitOpcode(w io.ByteWriter, op Opcode) error {
 	return w.WriteByte(byte(op))
 }
 
 // EmitBool emits a bool type the given buffer.
-func EmitBool(w *bytes.Buffer, ok bool) error {
+func EmitBool(w io.ByteWriter, ok bool) error {
 	if ok {
 		return EmitOpcode(w, Opusht)
 	}
@@ -90,7 +91,7 @@ func EmitSyscall(w *bytes.Buffer, api string) error {
 	}
 	buf := make([]byte, len(api)+1)
 	buf[0] = byte(len(api))
-	copy(buf[1:len(buf)], []byte(api))
+	copy(buf[1:], []byte(api))
 	return Emit(w, Osyscall, buf)
 }
 
@@ -102,7 +103,7 @@ func EmitCall(w *bytes.Buffer, op Opcode, label int16) error {
 // EmitJmp emits a jump Opcode along with label to the given buffer.
 func EmitJmp(w *bytes.Buffer, op Opcode, label int16) error {
 	if !isOpcodeJmp(op) {
-		return fmt.Errorf("opcode %s is not a jump or call type", op)
+		return fmt.Errorf("opcode %s is not a jump or call type", op.String())
 	}
 	buf := make([]byte, 2)
 	binary.LittleEndian.PutUint16(buf, uint16(label))

pkg/vm/stack.go

@@ -33,7 +33,7 @@ type Element struct {
 	stack      *Stack
 }
 
-// NewElement returns a new Element object, with its underlying value infered
+// NewElement returns a new Element object, with its underlying value inferred
 // to the corresponding type.
 func NewElement(v interface{}) *Element {
 	return &Element{

pkg/vm/syscall.go

@@ -1,7 +1,7 @@
 package vm
 
 // Syscalls are a mapping between the syscall function name
-// and the registerd VM interop API.
+// and the registered VM interop API.
 var Syscalls = map[string]string{
 	// Storage API
 	"GetContext": "Neo.Storage.GetContext",

pkg/vm/vm.go

@@ -87,7 +87,7 @@ func (v *VM) LoadArgs(method []byte, args []StackItem) {
 		v.estack.PushVal(args)
 	}
 	if method != nil {
-		v.estack.PushVal([]byte(method))
+		v.estack.PushVal(method)
 	}
 }
 
@@ -104,7 +104,7 @@ func (v *VM) PrintOps() {
 		} else {
 			cursor = ""
 		}
-		fmt.Fprintf(w, "%d\t0x%2x\t%s\t%s\n", i, prog[i], Opcode(prog[i]), cursor)
+		fmt.Fprintf(w, "%d\t0x%2x\t%s\t%s\n", i, prog[i], Opcode(prog[i]).String(), cursor)
 
 	}
 	w.Flush()
@@ -142,7 +142,7 @@ func (v *VM) Load(prog []byte) {
 }
 
 // LoadScript will load a script from the internal script table. It
-// will immediatly push a new context created from this script to
+// will immediately push a new context created from this script to
 // the invocation stack and starts executing it.
 func (v *VM) LoadScript(b []byte) {
 	ctx := NewContext(b)
@@ -203,7 +203,7 @@ func (v *VM) Run() {
 		case breakState:
 			ctx := v.Context()
 			i, op := ctx.CurrInstr()
-			fmt.Printf("at breakpoint %d (%s)\n", i, op)
+			fmt.Printf("at breakpoint %d (%s)\n", i, op.String())
 			return
 		case faultState:
 			fmt.Println("FAULT")
@@ -229,7 +229,7 @@ func (v *VM) Step() {
 
 // execute performs an instruction cycle in the VM. Acting on the instruction (opcode).
 func (v *VM) execute(ctx *Context, op Opcode) {
-	// Instead of poluting the whole VM logic with error handling, we will recover
+	// Instead of polluting the whole VM logic with error handling, we will recover
 	// each panic at a central point, putting the VM in a fault state.
 	defer func() {
 		if err := recover(); err != nil {
@@ -713,7 +713,7 @@ func (v *VM) execute(ctx *Context, op Opcode) {
 		}
 
 	default:
-		panic(fmt.Sprintf("unknown opcode %s", op))
+		panic(fmt.Sprintf("unknown opcode %s", op.String()))
 	}
 }
 

pkg/wallet/wallet.go

@@ -16,13 +16,13 @@ type Wallet struct {
 	// Version of the wallet, used for later upgrades.
 	Version string `json:"version"`
 
-	// A list of accounts which decribes the details of each account
+	// A list of accounts which describes the details of each account
 	// in the wallet.
 	Accounts []*Account `json:"accounts"`
 
 	Scrypt scryptParams `json:"scrypt"`
 
-	// Extra metadata can be used for storing abritrary data.
+	// Extra metadata can be used for storing arbitrary data.
 	// This field can be empty.
 	Extra interface{} `json:"extra"`