travis: enable gometalinter (decred#603)

* Hook up gometalinter

* travis: enable unconvert

* travis: enable gosimple

.travis.yml

@@ -7,10 +7,8 @@ install:
   - go get -v github.com/Masterminds/glide
   - glide install
   - go install -v . ./cmd/...
-  - go get -v golang.org/x/tools/cmd/cover
-  - go get -v github.com/bradfitz/goimports
-  - go get -v github.com/golang/lint/golint
-  - go get -v github.com/davecgh/go-spew/spew
+  - go get -v github.com/alecthomas/gometalinter
+  - gometalinter --install
 script:
   - export PATH=$PATH:$HOME/gopath/bin
   - ./goclean.sh

addrmgr/addrmanager_test.go

@@ -259,7 +259,7 @@ func TestNeedMoreAddresses(t *testing.T) {
 	n := addrmgr.New("testneedmoreaddresses", lookupFunc)
 	addrsToAdd := 1500
 	b := n.NeedMoreAddresses()
-	if b == false {
+	if !b {
 		t.Errorf("Expected that we need more addresses")
 	}
 	addrs := make([]*wire.NetAddress, addrsToAdd)
@@ -288,7 +288,7 @@ func TestNeedMoreAddresses(t *testing.T) {
 	}
 
 	b = n.NeedMoreAddresses()
-	if b == true {
+	if b {
 		t.Errorf("Expected that we don't need more addresses")
 	}
 }

addrmgr/network.go

@@ -247,12 +247,12 @@ func GroupKey(na *wire.NetAddress) string {
 	}
 	if IsRFC6145(na) || IsRFC6052(na) {
 		// last four bytes are the ip address
-		ip := net.IP(na.IP[12:16])
+		ip := na.IP[12:16]
 		return ip.Mask(net.CIDRMask(16, 32)).String()
 	}
 
 	if IsRFC3964(na) {
-		ip := net.IP(na.IP[2:6])
+		ip := na.IP[2:6]
 		return ip.Mask(net.CIDRMask(16, 32)).String()
 
 	}

blockchain/chaingen/generator.go

@@ -427,7 +427,7 @@ func purchaseCommitmentScript(addr dcrutil.Address, amount, voteFeeLimit, revoca
 	copy(data[:], addr.ScriptAddress())
 	binary.LittleEndian.PutUint64(data[20:], uint64(amount))
 	data[27] |= 1 << 7
-	binary.LittleEndian.PutUint16(data[28:], uint16(limits))
+	binary.LittleEndian.PutUint16(data[28:], limits)
 	script, err := txscript.NewScriptBuilder().AddOp(txscript.OP_RETURN).
 		AddData(data[:]).Script()
 	if err != nil {
@@ -1066,7 +1066,7 @@ func (hp *hash256prng) uniformRandom(upperBound uint32) uint32 {
 	// (2^32 - (x*2)) % x == 2^32 % x when x <= 2^31
 	min := ((math.MaxUint32 - (upperBound * 2)) + 1) % upperBound
 	if upperBound > 0x80000000 {
-		min = uint32(1 + ^upperBound)
+		min = 1 + ^upperBound
 	}
 
 	r := hp.Hash256Rand()
@@ -1249,9 +1249,7 @@ func (g *Generator) ReplaceWithNVotes(numVotes uint16) func(*wire.MsgBlock) {
 
 		// Add back the original stake transactions other than the
 		// original stake votes that have been replaced.
-		for _, stakeTx := range b.STransactions[defaultNumVotes:] {
-			stakeTxns = append(stakeTxns, stakeTx)
-		}
+		stakeTxns = append(stakeTxns, b.STransactions[defaultNumVotes:]...)
 
 		// Update the block with the new stake transactions and the
 		// header with the new number of votes.

blockchain/common.go

@@ -21,7 +21,7 @@ import (
 // DoStxoTest does a test on a simulated blockchain to ensure that the data
 // stored in the STXO buckets is not corrupt.
 func (b *BlockChain) DoStxoTest() error {
-	err := b.db.View(func(dbTx database.Tx) error {
+	return b.db.View(func(dbTx database.Tx) error {
 		for i := int64(2); i <= b.bestNode.height; i++ {
 			block, err := dbFetchBlockByHeight(dbTx, i)
 			if err != nil {
@@ -39,20 +39,15 @@ func (b *BlockChain) DoStxoTest() error {
 				return err
 			}
 
-			if int(ntx) != len(stxos) {
+			if ntx != len(stxos) {
 				return fmt.Errorf("bad number of stxos calculated at "+
 					"height %v, got %v expected %v",
-					i, len(stxos), int(ntx))
+					i, len(stxos), ntx)
 			}
 		}
 
 		return nil
 	})
-	if err != nil {
-		return err
-	}
-
-	return nil
 }
 
 // DebugBlockHeaderString dumps a verbose message containing information about

blockchain/difficulty.go

@@ -494,7 +494,7 @@ func (b *BlockChain) calcNextRequiredStakeDifficulty(curNode *blockNode) (int64,
 	alpha := b.chainParams.StakeDiffAlpha
 	stakeDiffStartHeight := int64(b.chainParams.CoinbaseMaturity) +
 		1
-	maxRetarget := int64(b.chainParams.RetargetAdjustmentFactor)
+	maxRetarget := b.chainParams.RetargetAdjustmentFactor
 	TicketPoolWeight := int64(b.chainParams.TicketPoolSizeWeight)
 
 	// Number of nodes to traverse while calculating difficulty.
@@ -759,7 +759,7 @@ func (b *BlockChain) estimateNextStakeDifficulty(curNode *blockNode,
 	alpha := b.chainParams.StakeDiffAlpha
 	stakeDiffStartHeight := int64(b.chainParams.CoinbaseMaturity) +
 		1
-	maxRetarget := int64(b.chainParams.RetargetAdjustmentFactor)
+	maxRetarget := b.chainParams.RetargetAdjustmentFactor
 	TicketPoolWeight := int64(b.chainParams.TicketPoolSizeWeight)
 
 	// Number of nodes to traverse while calculating difficulty.

blockchain/indexers/manager.go

@@ -278,10 +278,7 @@ func (m *Manager) Init(chain *blockchain.BlockChain) error {
 		err := m.db.View(func(dbTx database.Tx) error {
 			idxKey := indexer.Key()
 			hash, height, err = dbFetchIndexerTip(dbTx, idxKey)
-			if err != nil {
-				return err
-			}
-			return nil
+			return err
 		})
 		if err != nil {
 			return err

blockchain/scriptval.go

@@ -215,12 +215,7 @@ func ValidateTransactionScripts(tx *dcrutil.Tx, utxoView *UtxoViewpoint, flags t
 	}
 
 	// Validate all of the inputs.
-	validator := newTxValidator(utxoView, flags, sigCache)
-	if err := validator.Validate(txValItems); err != nil {
-		return err
-	}
-
-	return nil
+	return newTxValidator(utxoView, flags, sigCache).Validate(txValItems)
 
 }
 
@@ -263,10 +258,5 @@ func checkBlockScripts(block *dcrutil.Block, utxoView *UtxoViewpoint, txTree boo
 	}
 
 	// Validate all of the inputs.
-	validator := newTxValidator(utxoView, scriptFlags, sigCache)
-	if err := validator.Validate(txValItems); err != nil {
-		return err
-	}
-
-	return nil
+	return newTxValidator(utxoView, scriptFlags, sigCache).Validate(txValItems)
 }

blockchain/stake/internal/ticketdb/chainio.go

@@ -712,9 +712,5 @@ func DbCreate(dbTx database.Tx) error {
 	// Create the bucket that houses the tickets that were added with
 	// this block into the main chain.
 	_, err = meta.CreateBucket(dbnamespace.TicketsInBlockBucketName)
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return err
 }

blockchain/stake/internal/ticketdb/chainio_test.go

@@ -446,11 +446,7 @@ func TestLiveDatabase(t *testing.T) {
 	var dbi *DatabaseInfo
 	err = testDb.View(func(dbTx database.Tx) error {
 		dbi, err = DbFetchDatabaseInfo(dbTx)
-		if err != nil {
-			return err
-		}
-
-		return nil
+		return err
 	})
 	if err != nil {
 		t.Fatalf("%v", err.Error())
@@ -495,11 +491,7 @@ func TestLiveDatabase(t *testing.T) {
 	ticketMap2 := make(map[tickettreap.Key]*tickettreap.Value)
 	err = testDb.View(func(dbTx database.Tx) error {
 		treap, err = DbLoadAllTickets(dbTx, dbnamespace.LiveTicketsBucketName)
-		if err != nil {
-			return err
-		}
-
-		return nil
+		return err
 	})
 	if err != nil {
 		t.Fatalf("%v", err.Error())

blockchain/stake/internal/tickettreap/immutable_test.go

@@ -36,7 +36,7 @@ func TestImmutableEmpty(t *testing.T) {
 
 	// Ensure there are no errors with requesting keys from an empty treap.
 	key := uint32ToKey(0)
-	if gotVal := testTreap.Has(key); gotVal != false {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -357,7 +357,7 @@ func TestImmutableDuplicatePut(t *testing.T) {
 		testTreap = testTreap.Put(key, expectedVal)
 
 		// Ensure the key still exists and is the new value.
-		if gotVal := testTreap.Has(key); gotVal != true {
+		if gotVal := testTreap.Has(key); !gotVal {
 			t.Fatalf("Has: unexpected result - got %v, want false",
 				gotVal)
 		}
@@ -386,7 +386,7 @@ func TestImmutableNilValue(t *testing.T) {
 	testTreap = testTreap.Put(key, nil)
 
 	// Ensure the key does NOT exist.
-	if gotVal := testTreap.Has(key); gotVal == true {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -412,10 +412,7 @@ func TestImmutableForEachStopIterator(t *testing.T) {
 	var numIterated int
 	testTreap.ForEach(func(k Key, v *Value) bool {
 		numIterated++
-		if numIterated == numItems/2 {
-			return false
-		}
-		return true
+		return numIterated != numItems/2
 	})
 	if numIterated != numItems/2 {
 		t.Fatalf("ForEach: unexpected iterate count - got %d, want %d",

blockchain/stake/internal/tickettreap/mutable_test.go

@@ -31,7 +31,7 @@ func TestMutableEmpty(t *testing.T) {
 
 	// Ensure there are no errors with requesting keys from an empty treap.
 	key := uint32ToKey(0)
-	if gotVal := testTreap.Has(key); gotVal != false {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -408,7 +408,7 @@ func TestMutableDuplicatePut(t *testing.T) {
 		testTreap.Put(key, expectedVal)
 
 		// Ensure the key still exists and is the new value.
-		if gotVal := testTreap.Has(key); gotVal != true {
+		if gotVal := testTreap.Has(key); !gotVal {
 			t.Fatalf("Has: unexpected result - got %v, want false",
 				gotVal)
 		}
@@ -437,7 +437,7 @@ func TestMutableNilValue(t *testing.T) {
 	testTreap.Put(key, nil)
 
 	// Ensure the key does NOT exist.
-	if gotVal := testTreap.Has(key); gotVal == true {
+	if gotVal := testTreap.Has(key); gotVal {
 		t.Fatalf("Has: unexpected result - got %v, want false", gotVal)
 	}
 	if gotVal := testTreap.Get(key); gotVal != nil {
@@ -463,10 +463,7 @@ func TestMutableForEachStopIterator(t *testing.T) {
 	var numIterated int
 	testTreap.ForEach(func(k Key, v *Value) bool {
 		numIterated++
-		if numIterated == numItems/2 {
-			return false
-		}
-		return true
+		return numIterated != numItems/2
 	})
 	if numIterated != numItems/2 {
 		t.Fatalf("ForEach: unexpected iterate count - got %d, want %d",

blockchain/stake/staketx.go

@@ -873,10 +873,10 @@ func IsSStx(tx *wire.MsgTx) (bool, error) {
 		outputScriptBuffer := bytes.NewBuffer(rawScript)
 		outputScriptPrefix := outputScriptBuffer.Next(2)
 
-		minPush := uint8(validSStxAddressOutMinPrefix[1])
-		maxPush := uint8(validSStxAddressOutMinPrefix[1]) +
+		minPush := validSStxAddressOutMinPrefix[1]
+		maxPush := validSStxAddressOutMinPrefix[1] +
 			(MaxSingleBytePushLength - minPush)
-		pushLen := uint8(outputScriptPrefix[1])
+		pushLen := outputScriptPrefix[1]
 		pushLengthValid := (pushLen >= minPush) && (pushLen <= maxPush)
 		// The first byte should be OP_RETURN, while the second byte should be a
 		// valid push length.
@@ -1034,10 +1034,10 @@ func IsSSGen(tx *wire.MsgTx) (bool, error) {
 	firstOutputScriptBuffer := bytes.NewBuffer(firstOutputScript)
 	firstOutputScriptPrefix := firstOutputScriptBuffer.Next(2)
 
-	minPush := uint8(validSSGenVoteOutMinPrefix[1])
-	maxPush := uint8(validSSGenVoteOutMinPrefix[1]) +
+	minPush := validSSGenVoteOutMinPrefix[1]
+	maxPush := validSSGenVoteOutMinPrefix[1] +
 		(MaxSingleBytePushLength - minPush)
-	pushLen := uint8(firstOutputScriptPrefix[1])
+	pushLen := firstOutputScriptPrefix[1]
 	pushLengthValid := (pushLen >= minPush) && (pushLen <= maxPush)
 	// The first byte should be OP_RETURN, while the second byte should be a
 	// valid push length.