all: simplify nested complexity and if blocks ending with a return statement (#21854)

Changes:

    Simplify nested complexity
    If an if blocks ends with a return statement then remove the else nesting.

Most of the changes has also been reported in golint https://goreportcard.com/report/github.com/ethereum/go-ethereum#golint

cmd/clef/main.go

@@ -747,12 +747,10 @@ func DefaultConfigDir() string {
 			appdata := os.Getenv("APPDATA")
 			if appdata != "" {
 				return filepath.Join(appdata, "Signer")
-			} else {
-				return filepath.Join(home, "AppData", "Roaming", "Signer")
 			}
-		} else {
-			return filepath.Join(home, ".clef")
+			return filepath.Join(home, "AppData", "Roaming", "Signer")
 		}
+		return filepath.Join(home, ".clef")
 	}
 	// As we cannot guess a stable location, return empty and handle later
 	return ""

cmd/utils/flags.go

@@ -1695,19 +1695,18 @@ func RegisterEthService(stack *node.Node, cfg *eth.Config) ethapi.Backend {
 			Fatalf("Failed to register the Ethereum service: %v", err)
 		}
 		return backend.ApiBackend
-	} else {
-		backend, err := eth.New(stack, cfg)
+	}
+	backend, err := eth.New(stack, cfg)
+	if err != nil {
+		Fatalf("Failed to register the Ethereum service: %v", err)
+	}
+	if cfg.LightServ > 0 {
+		_, err := les.NewLesServer(stack, backend, cfg)
 		if err != nil {
-			Fatalf("Failed to register the Ethereum service: %v", err)
-		}
-		if cfg.LightServ > 0 {
-			_, err := les.NewLesServer(stack, backend, cfg)
-			if err != nil {
-				Fatalf("Failed to create the LES server: %v", err)
-			}
+			Fatalf("Failed to create the LES server: %v", err)
 		}
-		return backend.APIBackend
 	}
+	return backend.APIBackend
 }
 
 // RegisterEthStatsService configures the Ethereum Stats daemon and adds it to

console/bridge.go

@@ -144,15 +144,14 @@ func (b *bridge) OpenWallet(call jsre.Call) (goja.Value, error) {
 		if val, err = openWallet(goja.Null(), wallet, passwd); err != nil {
 			if !strings.HasSuffix(err.Error(), scwallet.ErrPINNeeded.Error()) {
 				return nil, err
-			} else {
-				// PIN input requested, fetch from the user and call open again
-				input, err := b.prompter.PromptPassword("Please enter current PIN: ")
-				if err != nil {
-					return nil, err
-				}
-				if val, err = openWallet(goja.Null(), wallet, call.VM.ToValue(input)); err != nil {
-					return nil, err
-				}
+			}
+			// PIN input requested, fetch from the user and call open again
+			input, err := b.prompter.PromptPassword("Please enter current PIN: ")
+			if err != nil {
+				return nil, err
+			}
+			if val, err = openWallet(goja.Null(), wallet, call.VM.ToValue(input)); err != nil {
+				return nil, err
 			}
 		}
 

core/headerchain.go

@@ -369,9 +369,8 @@ func (hc *HeaderChain) GetAncestor(hash common.Hash, number, ancestor uint64, ma
 		// in this case it is cheaper to just read the header
 		if header := hc.GetHeader(hash, number); header != nil {
 			return header.ParentHash, number - 1
-		} else {
-			return common.Hash{}, 0
 		}
+		return common.Hash{}, 0
 	}
 	for ancestor != 0 {
 		if rawdb.ReadCanonicalHash(hc.chainDb, number) == hash {

crypto/bls12381/g1.go

@@ -266,9 +266,8 @@ func (g *G1) Add(r, p1, p2 *PointG1) *PointG1 {
 	if t[1].equal(t[3]) {
 		if t[0].equal(t[2]) {
 			return g.Double(r, p1)
-		} else {
-			return r.Zero()
 		}
+		return r.Zero()
 	}
 	sub(t[1], t[1], t[3])
 	double(t[4], t[1])

crypto/bls12381/g2.go

@@ -287,9 +287,8 @@ func (g *G2) Add(r, p1, p2 *PointG2) *PointG2 {
 	if t[1].equal(t[3]) {
 		if t[0].equal(t[2]) {
 			return g.Double(r, p1)
-		} else {
-			return r.Zero()
 		}
+		return r.Zero()
 	}
 	g.f.sub(t[1], t[1], t[3])
 	g.f.double(t[4], t[1])

les/benchmark.go

@@ -75,9 +75,8 @@ func (b *benchmarkBlockHeaders) init(h *serverHandler, count int) error {
 func (b *benchmarkBlockHeaders) request(peer *serverPeer, index int) error {
 	if b.byHash {
 		return peer.requestHeadersByHash(0, b.hashes[index], b.amount, b.skip, b.reverse)
-	} else {
-		return peer.requestHeadersByNumber(0, uint64(b.offset+rand.Int63n(b.randMax)), b.amount, b.skip, b.reverse)
 	}
+	return peer.requestHeadersByNumber(0, uint64(b.offset+rand.Int63n(b.randMax)), b.amount, b.skip, b.reverse)
 }
 
 // benchmarkBodiesOrReceipts implements requestBenchmark
@@ -98,9 +97,8 @@ func (b *benchmarkBodiesOrReceipts) init(h *serverHandler, count int) error {
 func (b *benchmarkBodiesOrReceipts) request(peer *serverPeer, index int) error {
 	if b.receipts {
 		return peer.requestReceipts(0, []common.Hash{b.hashes[index]})
-	} else {
-		return peer.requestBodies(0, []common.Hash{b.hashes[index]})
 	}
+	return peer.requestBodies(0, []common.Hash{b.hashes[index]})
 }
 
 // benchmarkProofsOrCode implements requestBenchmark
@@ -119,9 +117,8 @@ func (b *benchmarkProofsOrCode) request(peer *serverPeer, index int) error {
 	rand.Read(key)
 	if b.code {
 		return peer.requestCode(0, []CodeReq{{BHash: b.headHash, AccKey: key}})
-	} else {
-		return peer.requestProofs(0, []ProofReq{{BHash: b.headHash, Key: key}})
 	}
+	return peer.requestProofs(0, []ProofReq{{BHash: b.headHash, Key: key}})
 }
 
 // benchmarkHelperTrie implements requestBenchmark

les/lespay/server/balance.go

@@ -588,9 +588,8 @@ func (n *NodeBalance) timeUntil(priority int64) (time.Duration, bool) {
 			}
 			dt = float64(posBalance-newBalance) / timePrice
 			return time.Duration(dt), true
-		} else {
-			dt = float64(posBalance) / timePrice
 		}
+		dt = float64(posBalance) / timePrice
 	} else {
 		if priority > 0 {
 			return 0, false

les/lespay/server/balance_tracker.go

@@ -261,9 +261,8 @@ func (bt *BalanceTracker) storeBalance(id []byte, neg bool, value utils.ExpiredV
 func (bt *BalanceTracker) canDropBalance(now mclock.AbsTime, neg bool, b utils.ExpiredValue) bool {
 	if neg {
 		return b.Value(bt.negExp.LogOffset(now)) <= negThreshold
-	} else {
-		return b.Value(bt.posExp.LogOffset(now)) <= posThreshold
 	}
+	return b.Value(bt.posExp.LogOffset(now)) <= posThreshold
 }
 
 // updateTotalBalance adjusts the total balance after executing given callback.

les/lespay/server/prioritypool.go

@@ -288,9 +288,8 @@ func activePriority(a interface{}, now mclock.AbsTime) int64 {
 	}
 	if c.bias == 0 {
 		return invertPriority(c.nodePriority.Priority(now, c.capacity))
-	} else {
-		return invertPriority(c.nodePriority.EstMinPriority(now+mclock.AbsTime(c.bias), c.capacity, true))
 	}
+	return invertPriority(c.nodePriority.EstMinPriority(now+mclock.AbsTime(c.bias), c.capacity, true))
 }
 
 // activeMaxPriority callback returns estimated maximum priority of ppNodeInfo item in activeQueue

les/odr_requests.go

@@ -329,9 +329,8 @@ func (r *ChtRequest) CanSend(peer *serverPeer) bool {
 
 	if r.Untrusted {
 		return peer.headInfo.Number >= r.BlockNum && peer.id == r.PeerId
-	} else {
-		return peer.headInfo.Number >= r.Config.ChtConfirms && r.ChtNum <= (peer.headInfo.Number-r.Config.ChtConfirms)/r.Config.ChtSize
 	}
+	return peer.headInfo.Number >= r.Config.ChtConfirms && r.ChtNum <= (peer.headInfo.Number-r.Config.ChtConfirms)/r.Config.ChtSize
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)

les/serverpool.go

@@ -112,9 +112,8 @@ var (
 				}
 				enc, err := rlp.EncodeToBytes(&ne)
 				return enc, err
-			} else {
-				return nil, errors.New("invalid field type")
 			}
+			return nil, errors.New("invalid field type")
 		},
 		func(enc []byte) (interface{}, error) {
 			var ne nodeHistoryEnc

les/serverpool_test.go

@@ -119,31 +119,28 @@ func (s *serverPoolTest) start() {
 				s.clock.Sleep(time.Second * 5)
 				s.endWait()
 				return -1
-			} else {
-				switch idx % 3 {
-				case 0:
-					// pre-neg returns true only if connection is possible
-					if canConnect {
-						return 1
-					} else {
-						return 0
-					}
-				case 1:
-					// pre-neg returns true but connection might still fail
+			}
+			switch idx % 3 {
+			case 0:
+				// pre-neg returns true only if connection is possible
+				if canConnect {
+					return 1
+				}
+				return 0
+			case 1:
+				// pre-neg returns true but connection might still fail
+				return 1
+			case 2:
+				// pre-neg returns true if connection is possible, otherwise timeout (node unresponsive)
+				if canConnect {
 					return 1
-				case 2:
-					// pre-neg returns true if connection is possible, otherwise timeout (node unresponsive)
-					if canConnect {
-						return 1
-					} else {
-						s.beginWait()
-						s.clock.Sleep(time.Second * 5)
-						s.endWait()
-						return -1
-					}
 				}
+				s.beginWait()
+				s.clock.Sleep(time.Second * 5)
+				s.endWait()
 				return -1
 			}
+			return -1
 		}
 	}
 

p2p/nat/nat.go

@@ -219,9 +219,8 @@ func (n *autodisc) String() string {
 	defer n.mu.Unlock()
 	if n.found == nil {
 		return n.what
-	} else {
-		return n.found.String()
 	}
+	return n.found.String()
 }
 
 // wait blocks until auto-discovery has been performed.

p2p/nodestate/nodestate_test.go

@@ -240,9 +240,8 @@ func uint64FieldEnc(field interface{}) ([]byte, error) {
 	if u, ok := field.(uint64); ok {
 		enc, err := rlp.EncodeToBytes(&u)
 		return enc, err
-	} else {
-		return nil, errors.New("invalid field type")
 	}
+	return nil, errors.New("invalid field type")
 }
 
 func uint64FieldDec(enc []byte) (interface{}, error) {
@@ -254,9 +253,8 @@ func uint64FieldDec(enc []byte) (interface{}, error) {
 func stringFieldEnc(field interface{}) ([]byte, error) {
 	if s, ok := field.(string); ok {
 		return []byte(s), nil
-	} else {
-		return nil, errors.New("invalid field type")
 	}
+	return nil, errors.New("invalid field type")
 }
 
 func stringFieldDec(enc []byte) (interface{}, error) {

p2p/simulations/network.go

@@ -454,9 +454,8 @@ func (net *Network) getNodeIDs(excludeIDs []enode.ID) []enode.ID {
 	if len(excludeIDs) > 0 {
 		// Return the difference of nodeIDs and excludeIDs
 		return filterIDs(nodeIDs, excludeIDs)
-	} else {
-		return nodeIDs
 	}
+	return nodeIDs
 }
 
 // GetNodes returns the existing nodes.
@@ -472,9 +471,8 @@ func (net *Network) getNodes(excludeIDs []enode.ID) []*Node {
 	if len(excludeIDs) > 0 {
 		nodeIDs := net.getNodeIDs(excludeIDs)
 		return net.getNodesByID(nodeIDs)
-	} else {
-		return net.Nodes
 	}
+	return net.Nodes
 }
 
 // GetNodesByID returns existing nodes with the given enode.IDs.
@@ -1098,7 +1096,6 @@ func (net *Network) executeNodeEvent(e *Event) error {
 func (net *Network) executeConnEvent(e *Event) error {
 	if e.Conn.Up {
 		return net.Connect(e.Conn.One, e.Conn.Other)
-	} else {
-		return net.Disconnect(e.Conn.One, e.Conn.Other)
 	}
+	return net.Disconnect(e.Conn.One, e.Conn.Other)
 }

rlp/encode_test.go

@@ -39,9 +39,8 @@ func (e *testEncoder) EncodeRLP(w io.Writer) error {
 	}
 	if e.err != nil {
 		return e.err
-	} else {
-		w.Write([]byte{0, 1, 0, 1, 0, 1, 0, 1, 0, 1})
 	}
+	w.Write([]byte{0, 1, 0, 1, 0, 1, 0, 1, 0, 1})
 	return nil
 }
 

rpc/client.go

@@ -404,9 +404,8 @@ func (c *Client) Notify(ctx context.Context, method string, args ...interface{})
 
 	if c.isHTTP {
 		return c.sendHTTP(ctx, op, msg)
-	} else {
-		return c.send(ctx, op, msg)
 	}
+	return c.send(ctx, op, msg)
 }
 
 // EthSubscribe registers a subscripion under the "eth" namespace.

trie/committer.go

@@ -267,6 +267,5 @@ func estimateSize(n node) int {
 		return 1 + len(n)
 	default:
 		panic(fmt.Sprintf("node type %T", n))
-
 	}
 }