linting: apply errcheck part2

blockchain/pool.go

@@ -311,7 +311,10 @@ func (pool *BlockPool) makeNextRequester() {
 	pool.requesters[nextHeight] = request
 	pool.numPending++
 
-	request.Start()
+	_, err := request.Start()
+	if err != nil {
+		panic(err)
+	}
 }
 
 func (pool *BlockPool) sendRequest(height int, peerID string) {

config/toml_test.go

@@ -24,7 +24,10 @@ func TestEnsureRoot(t *testing.T) {
 	// setup temp dir for test
 	tmpDir, err := ioutil.TempDir("", "config-test")
 	require.Nil(err)
-	defer os.RemoveAll(tmpDir)
+	defer func() {
+		err := os.RemoveAll(tmpDir)
+		require.Nil(err)
+	}()
 
 	// create root dir
 	EnsureRoot(tmpDir)

consensus/common_test.go

@@ -268,7 +268,6 @@ func newConsensusStateWithConfigAndBlockStore(thisConfig *cfg.Config, state *sm.
 	eventBus.SetLogger(log.TestingLogger().With("module", "events"))
 	eventBus.Start()
 	cs.SetEventBus(eventBus)
-
 	return cs
 }
 

consensus/reactor.go

@@ -55,7 +55,9 @@ func NewConsensusReactor(consensusState *ConsensusState, fastSync bool) *Consens
 // OnStart implements BaseService.
 func (conR *ConsensusReactor) OnStart() error {
 	conR.Logger.Info("ConsensusReactor ", "fastSync", conR.FastSync())
-	conR.BaseReactor.OnStart()
+	if err := conR.BaseReactor.OnStart(); err != nil {
+		return err
+	}
 
 	err := conR.startBroadcastRoutine()
 	if err != nil {

consensus/reactor_test.go

@@ -112,7 +112,9 @@ func TestReactorProposalHeartbeats(t *testing.T) {
 	}, css)
 
 	// send a tx
-	css[3].mempool.CheckTx([]byte{1, 2, 3}, nil)
+	if err := css[3].mempool.CheckTx([]byte{1, 2, 3}, nil); err != nil {
+		t.Fatal(err)
+	}
 
 	// wait till everyone makes the first new block
 	timeoutWaitGroup(t, N, func(wg *sync.WaitGroup, j int) {

consensus/replay.go

@@ -100,7 +100,9 @@ func (cs *ConsensusState) catchupReplay(csHeight int) error {
 	// and Handshake could reuse ConsensusState if it weren't for this check (since we can crash after writing ENDHEIGHT).
 	gr, found, err := cs.wal.SearchForEndHeight(uint64(csHeight))
 	if gr != nil {
-		gr.Close()
+		if err := gr.Close(); err != nil {
+			return err
+		}
 	}
 	if found {
 		return fmt.Errorf("WAL should not contain #ENDHEIGHT %d.", csHeight)
@@ -112,6 +114,12 @@ func (cs *ConsensusState) catchupReplay(csHeight int) error {
 		cs.Logger.Error("Replay: wal.group.Search returned EOF", "#ENDHEIGHT", csHeight-1)
 	} else if err != nil {
 		return err
+	} else {
+		defer func() {
+			if err := gr.Close(); err != nil {
+				return
+			}
+		}()
 	}
 	if !found {
 		return errors.New(cmn.Fmt("Cannot replay height %d. WAL does not contain #ENDHEIGHT for %d.", csHeight, csHeight-1))
@@ -230,7 +238,9 @@ func (h *Handshaker) ReplayBlocks(appHash []byte, appBlockHeight int, proxyApp p
 	// If appBlockHeight == 0 it means that we are at genesis and hence should send InitChain
 	if appBlockHeight == 0 {
 		validators := types.TM2PB.Validators(h.state.Validators)
-		proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
+		if err := proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators}); err != nil {
+			return nil, err
+		}
 	}
 
 	// First handle edge cases and constraints on the storeBlockHeight
@@ -363,7 +373,10 @@ func newMockProxyApp(appHash []byte, abciResponses *sm.ABCIResponses) proxy.AppC
 		abciResponses: abciResponses,
 	})
 	cli, _ := clientCreator.NewABCIClient()
-	cli.Start()
+	_, err := cli.Start()
+	if err != nil {
+		panic(err)
+	}
 	return proxy.NewAppConnConsensus(cli)
 }
 

consensus/replay_file.go

@@ -65,7 +65,11 @@ func (cs *ConsensusState) ReplayFile(file string, console bool) error {
 	}
 
 	pb := newPlayback(file, fp, cs, cs.state.Copy())
-	defer pb.fp.Close()
+	defer func() {
+		if err := pb.fp.Close(); err != nil {
+			return
+		}
+	}()
 
 	var nextN int // apply N msgs in a row
 	var msg *TimedWALMessage
@@ -127,7 +131,9 @@ func (pb *playback) replayReset(count int, newStepCh chan interface{}) error {
 	newCS.SetEventBus(pb.cs.eventBus)
 	newCS.startForReplay()
 
-	pb.fp.Close()
+	if err := pb.fp.Close(); err != nil {
+		return err
+	}
 	fp, err := os.OpenFile(pb.fileName, os.O_RDONLY, 0666)
 	if err != nil {
 		return err
@@ -220,7 +226,9 @@ func (pb *playback) replayConsoleLoop() int {
 			defer pb.cs.eventBus.Unsubscribe(ctx, subscriber, types.EventQueryNewRoundStep)
 
 			if len(tokens) == 1 {
-				pb.replayReset(1, newStepCh)
+				if err := pb.replayReset(1, newStepCh); err != nil {
+					panic(err)
+				}
 			} else {
 				i, err := strconv.Atoi(tokens[1])
 				if err != nil {
@@ -228,7 +236,9 @@ func (pb *playback) replayConsoleLoop() int {
 				} else if i > pb.count {
 					fmt.Printf("argument to back must not be larger than the current count (%d)\n", pb.count)
 				} else {
-					pb.replayReset(i, newStepCh)
+					if err := pb.replayReset(i, newStepCh); err != nil {
+						panic(err)
+					}
 				}
 			}
 

consensus/replay_test.go

@@ -411,7 +411,9 @@ func buildAppStateFromChain(proxyApp proxy.AppConns,
 	}
 
 	validators := types.TM2PB.Validators(state.Validators)
-	proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
+	if err := proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators}); err != nil {
+		panic(err)
+	}
 
 	defer proxyApp.Stop()
 	switch mode {
@@ -445,7 +447,9 @@ func buildTMStateFromChain(config *cfg.Config, state *sm.State, chain []*types.B
 	defer proxyApp.Stop()
 
 	validators := types.TM2PB.Validators(state.Validators)
-	proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators})
+	if err := proxyApp.Consensus().InitChainSync(abci.RequestInitChain{validators}); err != nil {
+		panic(err)
+	}
 
 	var latestAppHash []byte
 
@@ -486,7 +490,11 @@ func makeBlockchainFromWAL(wal WAL) ([]*types.Block, []*types.Commit, error) {
 	if !found {
 		return nil, nil, errors.New(cmn.Fmt("WAL does not contain height %d.", 1))
 	}
-	defer gr.Close()
+	defer func() {
+		if err := gr.Close(); err != nil {
+			return
+		}
+	}()
 
 	// log.Notice("Build a blockchain by reading from the WAL")
 

consensus/state.go

@@ -225,11 +225,14 @@ func (cs *ConsensusState) OnStart() error {
 	}
 
 	// we need the timeoutRoutine for replay so
-	//  we don't block on the tick chan.
+	// we don't block on the tick chan.
 	// NOTE: we will get a build up of garbage go routines
-	//  firing on the tockChan until the receiveRoutine is started
+	// firing on the tockChan until the receiveRoutine is started
-	//  to deal with them (by that point, at most one will be valid)
+	// to deal with them (by that point, at most one will be valid)
-	cs.timeoutTicker.Start()
+	_, err := cs.timeoutTicker.Start()
+	if err != nil {
+		return err
+	}
 
 	// we may have lost some votes if the process crashed
 	// reload from consensus log to catchup
@@ -254,7 +257,10 @@ func (cs *ConsensusState) OnStart() error {
 // timeoutRoutine: receive requests for timeouts on tickChan and fire timeouts on tockChan
 // receiveRoutine: serializes processing of proposoals, block parts, votes; coordinates state transitions
 func (cs *ConsensusState) startRoutines(maxSteps int) {
-	cs.timeoutTicker.Start()
+	_, err := cs.timeoutTicker.Start()
+	if err != nil {
+		panic(err)
+	}
 	go cs.receiveRoutine(maxSteps)
 }
 
@@ -338,12 +344,16 @@ func (cs *ConsensusState) AddProposalBlockPart(height, round int, part *types.Pa
 
 // SetProposalAndBlock inputs the proposal and all block parts.
 func (cs *ConsensusState) SetProposalAndBlock(proposal *types.Proposal, block *types.Block, parts *types.PartSet, peerKey string) error {
-	cs.SetProposal(proposal, peerKey)
+	if err := cs.SetProposal(proposal, peerKey); err != nil {
+		return err
+	}
 	for i := 0; i < parts.Total(); i++ {
 		part := parts.GetPart(i)
-		cs.AddProposalBlockPart(proposal.Height, proposal.Round, part, peerKey)
+		if err := cs.AddProposalBlockPart(proposal.Height, proposal.Round, part, peerKey); err != nil {
+			return err
+		}
 	}
-	return nil // TODO errors
+	return nil
 }
 
 //------------------------------------------------------------

consensus/state_test.go

@@ -209,7 +209,9 @@ func TestBadProposal(t *testing.T) {
 	}
 
 	// set the proposal block
-	cs1.SetProposalAndBlock(proposal, propBlock, propBlockParts, "some peer")
+	if err := cs1.SetProposalAndBlock(proposal, propBlock, propBlockParts, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 
 	// start the machine
 	startTestRound(cs1, height, round)
@@ -478,7 +480,9 @@ func TestLockNoPOL(t *testing.T) {
 
 	// now we're on a new round and not the proposer
 	// so set the proposal block
-	cs1.SetProposalAndBlock(prop, propBlock, propBlock.MakePartSet(partSize), "")
+	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlock.MakePartSet(partSize), ""); err != nil {
+		t.Fatal(err)
+	}
 
 	<-proposalCh
 	<-voteCh // prevote
@@ -555,7 +559,9 @@ func TestLockPOLRelock(t *testing.T) {
 	<-timeoutWaitCh
 
 	//XXX: this isnt guaranteed to get there before the timeoutPropose ...
-	cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer")
+	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 
 	<-newRoundCh
 	t.Log("### ONTO ROUND 1")
@@ -667,7 +673,9 @@ func TestLockPOLUnlock(t *testing.T) {
 	lockedBlockHash := rs.LockedBlock.Hash()
 
 	//XXX: this isnt guaranteed to get there before the timeoutPropose ...
-	cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer")
+	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 
 	<-newRoundCh
 	t.Log("#### ONTO ROUND 1")
@@ -754,7 +762,9 @@ func TestLockPOLSafety1(t *testing.T) {
 	incrementRound(vs2, vs3, vs4)
 
 	//XXX: this isnt guaranteed to get there before the timeoutPropose ...
-	cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer")
+	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 
 	<-newRoundCh
 	t.Log("### ONTO ROUND 1")
@@ -866,7 +876,9 @@ func TestLockPOLSafety2(t *testing.T) {
 	startTestRound(cs1, height, 1)
 	<-newRoundCh
 
-	cs1.SetProposalAndBlock(prop1, propBlock1, propBlockParts1, "some peer")
+	if err := cs1.SetProposalAndBlock(prop1, propBlock1, propBlockParts1, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 	<-proposalCh
 
 	<-voteCh // prevote
@@ -891,7 +903,9 @@ func TestLockPOLSafety2(t *testing.T) {
 	if err := vs3.SignProposal(config.ChainID, newProp); err != nil {
 		t.Fatal(err)
 	}
-	cs1.SetProposalAndBlock(newProp, propBlock0, propBlockParts0, "some peer")
+	if err := cs1.SetProposalAndBlock(newProp, propBlock0, propBlockParts0, "some peer"); err != nil {
+		t.Fatal(err)
+	}
 
 	// Add the pol votes
 	addVotes(cs1, prevotes...)

mempool/mempool.go

@@ -189,8 +189,14 @@ func (mem *Mempool) CheckTx(tx types.Tx, cb func(*abci.Response)) (err error) {
 	// WAL
 	if mem.wal != nil {
 		// TODO: Notify administrators when WAL fails
-		mem.wal.Write([]byte(tx))
+		_, err := mem.wal.Write([]byte(tx))
-		mem.wal.Write([]byte("\n"))
+		if err != nil {
+			return err
+		}
+		_, err = mem.wal.Write([]byte("\n"))
+		if err != nil {
+			return err
+		}
 	}
 	// END WAL
 
@@ -332,9 +338,9 @@ func (mem *Mempool) collectTxs(maxTxs int) types.Txs {
 // NOTE: this should be called *after* block is committed by consensus.
 // NOTE: unsafe; Lock/Unlock must be managed by caller
 func (mem *Mempool) Update(height int, txs types.Txs) {
-	// TODO: check err ?
+	if err := mem.proxyAppConn.FlushSync(); err != nil { // To flush async resCb calls e.g. from CheckTx
-	mem.proxyAppConn.FlushSync() // To flush async resCb calls e.g. from CheckTx
+		panic(err)
-
+	}
 	// First, create a lookup map of txns in new txs.
 	txsMap := make(map[string]struct{})
 	for _, tx := range txs {

mempool/mempool_test.go

@@ -49,9 +49,11 @@ func checkTxs(t *testing.T, mempool *Mempool, count int) types.Txs {
 	for i := 0; i < count; i++ {
 		txBytes := make([]byte, 20)
 		txs[i] = txBytes
-		rand.Read(txBytes)
+		_, err := rand.Read(txBytes)
-		err := mempool.CheckTx(txBytes, nil)
 		if err != nil {
+			t.Error(err)
+		}
+		if err := mempool.CheckTx(txBytes, nil); err != nil {
 			t.Fatal("Error after CheckTx: %v", err)
 		}
 	}

p2p/upnp/probe.go

@@ -97,11 +97,12 @@ func Probe(logger log.Logger) (caps UPNPCapabilities, err error) {
 
 	// Deferred cleanup
 	defer func() {
-		err = nat.DeletePortMapping("tcp", intPort, extPort)
+		if err := nat.DeletePortMapping("tcp", intPort, extPort); err != nil {
-		if err != nil {
 			logger.Error(cmn.Fmt("Port mapping delete error: %v", err))
 		}
-		listener.Close()
+		if err := listener.Close(); err != nil {
+			panic(err)
+		}
 	}()
 
 	supportsHairpin := testHairpin(listener, fmt.Sprintf("%v:%v", ext, extPort), logger)

p2p/upnp/upnp.go

@@ -40,11 +40,14 @@ func Discover() (nat NAT, err error) {
 		return
 	}
 	socket := conn.(*net.UDPConn)
-	defer socket.Close()
+	defer func() {
+		if err := socket.Close(); err != nil {
+			return
+		}
+	}()
 
-	err = socket.SetDeadline(time.Now().Add(3 * time.Second))
+	if err := socket.SetDeadline(time.Now().Add(3 * time.Second)); err != nil {
-	if err != nil {
+		return nil, err
-		return
 	}
 
 	st := "InternetGatewayDevice:1"
@@ -198,7 +201,11 @@ func getServiceURL(rootURL string) (url, urnDomain string, err error) {
 	if err != nil {
 		return
 	}
-	defer r.Body.Close()
+	defer func() {
+		if err := r.Body.Close(); err != nil {
+			return
+		}
+	}()
 	if r.StatusCode >= 400 {
 		err = errors.New(string(r.StatusCode))
 		return
@@ -296,15 +303,25 @@ func (n *upnpNAT) getExternalIPAddress() (info statusInfo, err error) {
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "GetExternalIPAddress", message, n.urnDomain)
 	if response != nil {
-		defer response.Body.Close()
+		defer func() {
+			if err := response.Body.Close(); err != nil {
+				return
+			}
+		}()
 	}
 	if err != nil {
 		return
 	}
 	var envelope Envelope
 	data, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return
+	}
 	reader := bytes.NewReader(data)
-	xml.NewDecoder(reader).Decode(&envelope)
+	err = xml.NewDecoder(reader).Decode(&envelope)
+	if err != nil {
+		return
+	}
 
 	info = statusInfo{envelope.Soap.ExternalIP.IPAddress}
 
@@ -339,7 +356,11 @@ func (n *upnpNAT) AddPortMapping(protocol string, externalPort, internalPort int
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "AddPortMapping", message, n.urnDomain)
 	if response != nil {
-		defer response.Body.Close()
+		defer func() {
+			if err := response.Body.Close(); err != nil {
+				return
+			}
+		}()
 	}
 	if err != nil {
 		return
@@ -365,7 +386,11 @@ func (n *upnpNAT) DeletePortMapping(protocol string, externalPort, internalPort
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "DeletePortMapping", message, n.urnDomain)
 	if response != nil {
-		defer response.Body.Close()
+		defer func() {
+			if err := response.Body.Close(); err != nil {
+				return
+			}
+		}()
 	}
 	if err != nil {
 		return