consensus, core: drop all the legacy custom core error types

15 files changed, 114 insertions, 260 deletions

diff --git a/consensus/errors.go b/consensus/errors.go
new file mode 100644
index 000000000..f94bcb329
--- /dev/null
+++ b/consensus/errors.go
@@ -0,0 +1,41 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package consensus
+
+import "errors"
+
+var (
+	// ErrUnknownAncestor is returned when validating a block requires an ancestor
+	// that is unknown.
+	ErrUnknownAncestor = errors.New("unknown ancestor")
+
+	// ErrLargeBlockTime is returned if the value of the timestamp is beyond
+	// any reasonable value.
+	ErrLargeBlockTime = errors.New("timestamp too big")
+
+	// ErrZeroBlockTime is returned if the block's timestamp is the same as the one
+	// its parent has.
+	ErrZeroBlockTime = errors.New("timestamp equals parent's")
+
+	// ErrFutureBlock is returned when a block's timestamp is in the future according
+	// to the current node.
+	ErrFutureBlock = errors.New("block in the future")
+
+	// ErrInvalidNumber is returned if a block's number doesn't equal it's parent's
+	// plus one.
+	ErrInvalidNumber = errors.New("invalid block number")
+)
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index 603be3e53..4a3a74a93 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -42,20 +42,15 @@ var (
 )
 
 var (
-	ErrInvalidChain        = errors.New("invalid header chain")
-	ErrParentUnknown       = errors.New("parent not known locally")
-	ErrFutureBlock         = errors.New("block in the future")
-	ErrLargeBlockTimestamp = errors.New("timestamp too big")
-	ErrZeroBlockTime       = errors.New("timestamp equals parent's")
-	ErrInvalidNumber       = errors.New("invalid block number")
-	ErrTooManyUncles       = errors.New("too many uncles")
-	ErrDuplicateUncle      = errors.New("duplicate uncle")
-	ErrUncleIsAncestor     = errors.New("uncle is ancestor")
-	ErrDanglingUncle       = errors.New("uncle's parent is not ancestor")
-	ErrNonceOutOfRange     = errors.New("nonce out of range")
-	ErrInvalidDifficulty   = errors.New("non-positive difficulty")
-	ErrInvalidMixDigest    = errors.New("invalid mix digest")
-	ErrInvalidPoW          = errors.New("invalid proof-of-work")
+	ErrInvalidChain      = errors.New("invalid header chain")
+	ErrTooManyUncles     = errors.New("too many uncles")
+	ErrDuplicateUncle    = errors.New("duplicate uncle")
+	ErrUncleIsAncestor   = errors.New("uncle is ancestor")
+	ErrDanglingUncle     = errors.New("uncle's parent is not ancestor")
+	ErrNonceOutOfRange   = errors.New("nonce out of range")
+	ErrInvalidDifficulty = errors.New("non-positive difficulty")
+	ErrInvalidMixDigest  = errors.New("invalid mix digest")
+	ErrInvalidPoW        = errors.New("invalid proof-of-work")
 )
 
 // VerifyHeader checks whether a header conforms to the consensus rules of the
@@ -72,7 +67,7 @@ func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.He
 	}
 	parent := chain.GetHeader(header.ParentHash, number-1)
 	if parent == nil {
-		return ErrParentUnknown
+		return consensus.ErrUnknownAncestor
 	}
 	// Sanity checks passed, do a proper verification
 	return ethash.verifyHeader(chain, header, parent, false, seal)
@@ -125,7 +120,7 @@ func (ethash *Ethash) VerifyHeaders(chain consensus.ChainReader, headers []*type
 				case chain.GetHeader(headers[index].Hash(), headers[index].Number.Uint64()-1) != nil:
 					outputs <- result{index: index, err: nil}
 				case parent == nil:
-					failure = ErrParentUnknown
+					failure = consensus.ErrUnknownAncestor
 					outputs <- result{index: index, err: failure}
 				default:
 					failure = ethash.verifyHeader(chain, headers[index], parent, false, seals[index])
@@ -254,15 +249,15 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 	// Verify the header's timestamp
 	if uncle {
 		if header.Time.Cmp(math.MaxBig256) > 0 {
-			return ErrLargeBlockTimestamp
+			return consensus.ErrLargeBlockTime
 		}
 	} else {
 		if header.Time.Cmp(big.NewInt(time.Now().Unix())) > 0 {
-			return ErrFutureBlock
+			return consensus.ErrFutureBlock
 		}
 	}
 	if header.Time.Cmp(parent.Time) <= 0 {
-		return ErrZeroBlockTime
+		return consensus.ErrZeroBlockTime
 	}
 	// Verify the block's difficulty based in it's timestamp and parent's difficulty
 	expected := CalcDifficulty(chain.Config(), header.Time.Uint64(), parent.Time.Uint64(), parent.Number, parent.Difficulty)
@@ -282,7 +277,7 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 	}
 	// Verify that the block number is parent's +1
 	if diff := new(big.Int).Sub(header.Number, parent.Number); diff.Cmp(big.NewInt(1)) != 0 {
-		return ErrInvalidNumber
+		return consensus.ErrInvalidNumber
 	}
 	// Verify the engine specific seal securing the block
 	if seal {
@@ -449,7 +444,7 @@ func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Head
 func (ethash *Ethash) Prepare(chain consensus.ChainReader, header *types.Header) error {
 	parent := chain.GetHeader(header.ParentHash, header.Number.Uint64()-1)
 	if parent == nil {
-		return ErrParentUnknown
+		return consensus.ErrUnknownAncestor
 	}
 	header.Difficulty = CalcDifficulty(chain.Config(), header.Time.Uint64(),
 		parent.Time.Uint64(), parent.Number, parent.Difficulty)
diff --git a/core/block_validator.go b/core/block_validator.go
index 00457dd7a..4f85df007 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -54,15 +54,15 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 	// Check whether the block's known, and if not, that it's linkable
 	if v.bc.HasBlock(block.Hash()) {
 		if _, err := state.New(block.Root(), v.bc.chainDb); err == nil {
-			return &KnownBlockError{block.Number(), block.Hash()}
+			return ErrKnownBlock
 		}
 	}
 	parent := v.bc.GetBlock(block.ParentHash(), block.NumberU64()-1)
 	if parent == nil {
-		return ParentError(block.ParentHash())
+		return consensus.ErrUnknownAncestor
 	}
 	if _, err := state.New(parent.Root(), v.bc.chainDb); err != nil {
-		return ParentError(block.ParentHash())
+		return consensus.ErrUnknownAncestor
 	}
 	// Header validity is known at this point, check the uncles and transactions
 	header := block.Header()
@@ -82,10 +82,10 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 // transition, such as amount of used gas, the receipt roots and the state root
 // itself. ValidateState returns a database batch if the validation was a success
 // otherwise nil and an error is returned.
-func (v *BlockValidator) ValidateState(block, parent *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas *big.Int) (err error) {
+func (v *BlockValidator) ValidateState(block, parent *types.Block, statedb *state.StateDB, receipts types.Receipts, usedGas *big.Int) error {
 	header := block.Header()
 	if block.GasUsed().Cmp(usedGas) != 0 {
-		return ValidationError(fmt.Sprintf("invalid gas used (remote: %v local: %v)", block.GasUsed(), usedGas))
+		return fmt.Errorf("invalid gas used (remote: %v local: %v)", block.GasUsed(), usedGas)
 	}
 	// Validate the received block's bloom with the one derived from the generated receipts.
 	// For valid blocks this should always validate to true.
diff --git a/core/blockchain.go b/core/blockchain.go
index 4793431d8..b601c462c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -831,7 +831,7 @@ func (self *BlockChain) WriteBlock(block *types.Block) (status WriteStatus, err
 	// Calculate the total difficulty of the block
 	ptd := self.GetTd(block.ParentHash(), block.NumberU64()-1)
 	if ptd == nil {
-		return NonStatTy, ParentError(block.ParentHash())
+		return NonStatTy, consensus.ErrUnknownAncestor
 	}
 	// Make sure no inconsistent state is leaked during insertion
 	self.mu.Lock()
@@ -918,9 +918,8 @@ func (self *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 		}
 		// If the header is a banned one, straight out abort
 		if BadHashes[block.Hash()] {
-			err := BadHashError(block.Hash())
-			self.reportBlock(block, nil, err)
-			return i, err
+			self.reportBlock(block, nil, ErrBlacklistedHash)
+			return i, ErrBlacklistedHash
 		}
 		// Wait for the block's verification to complete
 		bstart := time.Now()
@@ -930,25 +929,25 @@ func (self *BlockChain) InsertChain(chain types.Blocks) (int, error) {
 			err = self.Validator().ValidateBody(block)
 		}
 		if err != nil {
-			if IsKnownBlockErr(err) {
+			if err == ErrKnownBlock {
 				stats.ignored++
 				continue
 			}
 
-			if err == BlockFutureErr {
+			if err == consensus.ErrFutureBlock {
 				// Allow up to MaxFuture second in the future blocks. If this limit
 				// is exceeded the chain is discarded and processed at a later time
 				// if given.
 				max := big.NewInt(time.Now().Unix() + maxTimeFutureBlocks)
-				if block.Time().Cmp(max) == 1 {
-					return i, fmt.Errorf("%v: BlockFutureErr, %v > %v", BlockFutureErr, block.Time(), max)
+				if block.Time().Cmp(max) > 0 {
+					return i, fmt.Errorf("future block: %v > %v", block.Time(), max)
 				}
 				self.futureBlocks.Add(block.Hash(), block)
 				stats.queued++
 				continue
 			}
 
-			if IsParentErr(err) && self.futureBlocks.Contains(block.ParentHash()) {
+			if err == consensus.ErrUnknownAncestor && self.futureBlocks.Contains(block.ParentHash()) {
 				self.futureBlocks.Add(block.Hash(), block)
 				stats.queued++
 				continue
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index b2fb226db..d65571cde 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -126,7 +126,7 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 			err = blockchain.validator.ValidateBody(block)
 		}
 		if err != nil {
-			if IsKnownBlockErr(err) {
+			if err == ErrKnownBlock {
 				continue
 			}
 			return err
@@ -441,8 +441,8 @@ func testBadHashes(t *testing.T, full bool) {
 		BadHashes[headers[2].Hash()] = true
 		_, err = bc.InsertHeaderChain(headers, 1)
 	}
-	if !IsBadHashError(err) {
-		t.Errorf("error mismatch: want: BadHashError, have: %v", err)
+	if err != ErrBlacklistedHash {
+		t.Errorf("error mismatch: have: %v, want: %v", err, ErrBlacklistedHash)
 	}
 }
 
diff --git a/core/dao.go b/core/dao.go
index c43899e31..ff42a0e9d 100644
--- a/core/dao.go
+++ b/core/dao.go
@@ -18,6 +18,7 @@ package core
 
 import (
 	"bytes"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/core/state"
@@ -46,11 +47,11 @@ func ValidateDAOHeaderExtraData(config *params.ChainConfig, header *types.Header
 	// Depending whether we support or oppose the fork, validate the extra-data contents
 	if config.DAOForkSupport {
 		if !bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
-			return ValidationError("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
+			return fmt.Errorf("DAO pro-fork bad block extra-data: 0x%x", header.Extra)
 		}
 	} else {
 		if bytes.Equal(header.Extra, params.DAOForkBlockExtra) {
-			return ValidationError("DAO no-fork bad block extra-data: 0x%x", header.Extra)
+			return fmt.Errorf("DAO no-fork bad block extra-data: 0x%x", header.Extra)
 		}
 	}
 	// All ok, header has the same extra-data we expect
diff --git a/core/error.go b/core/error.go
index 0ba506f46..9ac4fff51 100644
--- a/core/error.go
+++ b/core/error.go
@@ -16,188 +16,16 @@
 
 package core
 
-import (
-	"errors"
-	"fmt"
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/common"
-)
+import "errors"
 
 var (
-	BlockNumberErr   = errors.New("block number invalid")
-	BlockFutureErr   = errors.New("block time is in the future")
-	BlockTSTooBigErr = errors.New("block time too big")
-	BlockEqualTSErr  = errors.New("block time stamp equal to previous")
-)
-
-// Parent error. In case a parent is unknown this error will be thrown
-// by the block manager
-type ParentErr struct {
-	Message string
-}
-
-func (err *ParentErr) Error() string {
-	return err.Message
-}
-
-func ParentError(hash common.Hash) error {
-	return &ParentErr{Message: fmt.Sprintf("Block's parent unknown %x", hash)}
-}
-
-func IsParentErr(err error) bool {
-	_, ok := err.(*ParentErr)
-	return ok
-}
-
-type UncleErr struct {
-	Message string
-}
-
-func (err *UncleErr) Error() string {
-	return err.Message
-}
-
-func UncleError(format string, v ...interface{}) error {
-	return &UncleErr{Message: fmt.Sprintf(format, v...)}
-}
-
-func IsUncleErr(err error) bool {
-	_, ok := err.(*UncleErr)
-	return ok
-}
-
-// Block validation error. If any validation fails, this error will be thrown
-type ValidationErr struct {
-	Message string
-}
-
-func (err *ValidationErr) Error() string {
-	return err.Message
-}
-
-func ValidationError(format string, v ...interface{}) *ValidationErr {
-	return &ValidationErr{Message: fmt.Sprintf(format, v...)}
-}
-
-func IsValidationErr(err error) bool {
-	_, ok := err.(*ValidationErr)
-	return ok
-}
-
-type NonceErr struct {
-	Message string
-	Is, Exp uint64
-}
-
-func (err *NonceErr) Error() string {
-	return err.Message
-}
-
-func NonceError(is, exp uint64) *NonceErr {
-	return &NonceErr{Message: fmt.Sprintf("Transaction w/ invalid nonce. tx=%d  state=%d)", is, exp), Is: is, Exp: exp}
-}
-
-func IsNonceErr(err error) bool {
-	_, ok := err.(*NonceErr)
-	return ok
-}
+	// ErrKnownBlock is returned when a block to import is already known locally.
+	ErrKnownBlock = errors.New("block already known")
 
-// BlockNonceErr indicates that a block's nonce is invalid.
-type BlockNonceErr struct {
-	Number *big.Int
-	Hash   common.Hash
-	Nonce  uint64
-}
+	// ErrGasLimitReached is returned by the gas pool if the amount of gas required
+	// by a transaction is higher than what's left in the block.
+	ErrGasLimitReached = errors.New("gas limit reached")
 
-func (err *BlockNonceErr) Error() string {
-	return fmt.Sprintf("nonce for #%d [%x…] is invalid (got %d)", err.Number, err.Hash, err.Nonce)
-}
-
-// IsBlockNonceErr returns true for invalid block nonce errors.
-func IsBlockNonceErr(err error) bool {
-	_, ok := err.(*BlockNonceErr)
-	return ok
-}
-
-type InvalidTxErr struct {
-	Message string
-}
-
-func (err *InvalidTxErr) Error() string {
-	return err.Message
-}
-
-func InvalidTxError(err error) *InvalidTxErr {
-	return &InvalidTxErr{fmt.Sprintf("%v", err)}
-}
-
-func IsInvalidTxErr(err error) bool {
-	_, ok := err.(*InvalidTxErr)
-	return ok
-}
-
-type TDError struct {
-	a, b *big.Int
-}
-
-func (self *TDError) Error() string {
-	return fmt.Sprintf("incoming chain has a lower or equal TD (%v <= %v)", self.a, self.b)
-}
-func IsTDError(e error) bool {
-	_, ok := e.(*TDError)
-	return ok
-}
-
-type KnownBlockError struct {
-	number *big.Int
-	hash   common.Hash
-}
-
-func (self *KnownBlockError) Error() string {
-	return fmt.Sprintf("block %v already known (%x)", self.number, self.hash[0:4])
-}
-func IsKnownBlockErr(e error) bool {
-	_, ok := e.(*KnownBlockError)
-	return ok
-}
-
-type ValueTransferError struct {
-	message string
-}
-
-func ValueTransferErr(str string, v ...interface{}) *ValueTransferError {
-	return &ValueTransferError{fmt.Sprintf(str, v...)}
-}
-
-func (self *ValueTransferError) Error() string {
-	return self.message
-}
-func IsValueTransferErr(e error) bool {
-	_, ok := e.(*ValueTransferError)
-	return ok
-}
-
-type BadHashError common.Hash
-
-func (h BadHashError) Error() string {
-	return fmt.Sprintf("Found known bad hash in chain %x", h[:])
-}
-
-func IsBadHashError(err error) bool {
-	_, ok := err.(BadHashError)
-	return ok
-}
-
-type GasLimitErr struct {
-	Have, Want *big.Int
-}
-
-func IsGasLimitErr(err error) bool {
-	_, ok := err.(*GasLimitErr)
-	return ok
-}
-
-func (err *GasLimitErr) Error() string {
-	return fmt.Sprintf("GasLimit reached. Have %d gas, transaction requires %d", err.Have, err.Want)
-}
+	// ErrBlacklistedHash is returned if a block to import is on the blacklist.
+	ErrBlacklistedHash = errors.New("blacklisted hash")
+)
diff --git a/core/gaspool.go b/core/gaspool.go
index f1c64c97a..ef99908cf 100644
--- a/core/gaspool.go
+++ b/core/gaspool.go
@@ -35,7 +35,7 @@ func (gp *GasPool) AddGas(amount *big.Int) *GasPool {
 func (gp *GasPool) SubGas(amount *big.Int) error {
 	i := (*big.Int)(gp)
 	if i.Cmp(amount) < 0 {
-		return &GasLimitErr{Have: new(big.Int).Set(i), Want: amount}
+		return ErrGasLimitReached
 	}
 	i.Sub(i, amount)
 	return nil
diff --git a/core/headerchain.go b/core/headerchain.go
index e2d0ff5b1..f58afc6ca 100644
--- a/core/headerchain.go
+++ b/core/headerchain.go
@@ -137,7 +137,7 @@ func (hc *HeaderChain) WriteHeader(header *types.Header) (status WriteStatus, er
 	// Calculate the total difficulty of the header
 	ptd := hc.GetTd(header.ParentHash, number-1)
 	if ptd == nil {
-		return NonStatTy, ParentError(header.ParentHash)
+		return NonStatTy, consensus.ErrUnknownAncestor
 	}
 	localTd := hc.GetTd(hc.currentHeaderHash, hc.currentHeader.Number.Uint64())
 	externTd := new(big.Int).Add(header.Difficulty, ptd)
@@ -246,7 +246,7 @@ func (hc *HeaderChain) ValidateHeaderChain(chain []*types.Header, checkFreq int)
 		}
 		// If the header is a banned one, straight out abort
 		if BadHashes[header.Hash()] {
-			return i, BadHashError(header.Hash())
+			return i, ErrBlacklistedHash
 		}
 		// Otherwise wait for headers checks and ensure they pass
 		if err := <-results; err != nil {
diff --git a/core/state_transition.go b/core/state_transition.go
index fb7518647..9e11144c6 100644
--- a/core/state_transition.go
+++ b/core/state_transition.go
@@ -18,6 +18,7 @@ package core
 
 import (
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -195,26 +196,17 @@ func (self *StateTransition) buyGas() error {
 	return nil
 }
 
-func (self *StateTransition) preCheck() (err error) {
+func (self *StateTransition) preCheck() error {
 	msg := self.msg
 	sender := self.from()
 
 	// Make sure this transaction's nonce is correct
 	if msg.CheckNonce() {
 		if n := self.state.GetNonce(sender.Address()); n != msg.Nonce() {
-			return NonceError(msg.Nonce(), n)
+			return fmt.Errorf("invalid nonce: have %d, expected %d", msg.Nonce(), n)
 		}
 	}
-
-	// Pre-pay gas
-	if err = self.buyGas(); err != nil {
-		if IsGasLimitErr(err) {
-			return err
-		}
-		return InvalidTxError(err)
-	}
-
-	return nil
+	return self.buyGas()
 }
 
 // TransitionDb will transition the state by applying the current message and returning the result
@@ -233,11 +225,10 @@ func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *b
 	// TODO convert to uint64
 	intrinsicGas := IntrinsicGas(self.data, contractCreation, homestead)
 	if intrinsicGas.BitLen() > 64 {
-		return nil, nil, nil, InvalidTxError(vm.ErrOutOfGas)
+		return nil, nil, nil, vm.ErrOutOfGas
 	}
-
 	if err = self.useGas(intrinsicGas.Uint64()); err != nil {
-		return nil, nil, nil, InvalidTxError(err)
+		return nil, nil, nil, err
 	}
 
 	var (
@@ -260,10 +251,9 @@ func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *b
 		// sufficient balance to make the transfer happen. The first
 		// balance transfer may never fail.
 		if vmerr == vm.ErrInsufficientBalance {
-			return nil, nil, nil, InvalidTxError(vmerr)
+			return nil, nil, nil, vmerr
 		}
 	}
-
 	requiredGas = new(big.Int).Set(self.gasUsed())
 
 	self.refundGas()
diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go
index 64a991069..98cc1a76b 100644
--- a/eth/fetcher/fetcher.go
+++ b/eth/fetcher/fetcher.go
@@ -23,7 +23,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
 	"gopkg.in/karalabe/cookiejar.v2/collections/prque"
@@ -654,7 +654,7 @@ func (f *Fetcher) insert(peer string, block *types.Block) {
 			propBroadcastOutTimer.UpdateSince(block.ReceivedAt)
 			go f.broadcastBlock(block, true)
 
-		case core.BlockFutureErr:
+		case consensus.ErrFutureBlock:
 			// Weird future block, don't fail, but neither propagate
 
 		default:
diff --git a/les/fetcher.go b/les/fetcher.go
index 353e91932..a294d00d5 100644
--- a/les/fetcher.go
+++ b/les/fetcher.go
@@ -24,6 +24,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/mclock"
+	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/light"
@@ -498,7 +499,7 @@ func (f *lightFetcher) processResponse(req fetchRequest, resp fetchResponse) boo
 		headers[int(req.amount)-1-i] = header
 	}
 	if _, err := f.chain.InsertHeaderChain(headers, 1); err != nil {
-		if err == core.BlockFutureErr {
+		if err == consensus.ErrFutureBlock {
 			return true
 		}
 		log.Debug("Failed to insert header chain", "err", err)
diff --git a/light/lightchain_test.go b/light/lightchain_test.go
index 41010cf57..21b621046 100644
--- a/light/lightchain_test.go
+++ b/light/lightchain_test.go
@@ -327,9 +327,8 @@ func TestBadHeaderHashes(t *testing.T) {
 	var err error
 	headers := makeHeaderChainWithDiff(bc.genesisBlock, []int{1, 2, 4}, 10)
 	core.BadHashes[headers[2].Hash()] = true
-	_, err = bc.InsertHeaderChain(headers, 1)
-	if !core.IsBadHashError(err) {
-		t.Errorf("error mismatch: want: BadHashError, have: %v", err)
+	if _, err = bc.InsertHeaderChain(headers, 1); err != core.ErrBlacklistedHash {
+		t.Errorf("error mismatch: have: %v, want %v", err, core.ErrBlacklistedHash)
 	}
 }
 
diff --git a/miner/worker.go b/miner/worker.go
index b2183b77d..8a67b12a6 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -503,13 +503,13 @@ func (self *worker) commitNewWork() {
 func (self *worker) commitUncle(work *Work, uncle *types.Header) error {
 	hash := uncle.Hash()
 	if work.uncles.Has(hash) {
-		return core.UncleError("uncle not unique")
+		return fmt.Errorf("uncle not unique")
 	}
 	if !work.ancestors.Has(uncle.ParentHash) {
-		return core.UncleError(fmt.Sprintf("uncle's parent unknown (%x)", uncle.ParentHash[0:4]))
+		return fmt.Errorf("uncle's parent unknown (%x)", uncle.ParentHash[0:4])
 	}
 	if work.family.Has(hash) {
-		return core.UncleError(fmt.Sprintf("uncle already in family (%x)", hash))
+		return fmt.Errorf("uncle already in family (%x)", hash)
 	}
 	work.uncles.Add(uncle.Hash())
 	return nil
@@ -554,23 +554,23 @@ func (env *Work) commitTransactions(mux *event.TypeMux, txs *types.TransactionsB
 		env.state.StartRecord(tx.Hash(), common.Hash{}, env.tcount)
 
 		err, logs := env.commitTransaction(tx, bc, gp)
-		switch {
-		case core.IsGasLimitErr(err):
+		switch err {
+		case core.ErrGasLimitReached:
 			// Pop the current out-of-gas transaction without shifting in the next from the account
 			log.Trace("Gas limit exceeded for current block", "sender", from)
 			txs.Pop()
 
-		case err != nil:
-			// Pop the current failed transaction without shifting in the next from the account
-			log.Trace("Transaction failed, will be removed", "hash", tx.Hash(), "err", err)
-			env.failedTxs = append(env.failedTxs, tx)
-			txs.Pop()
-
-		default:
+		case nil:
 			// Everything ok, collect the logs and shift in the next transaction from the same account
 			coalescedLogs = append(coalescedLogs, logs...)
 			env.tcount++
 			txs.Shift()
+
+		default:
+			// Pop the current failed transaction without shifting in the next from the account
+			log.Trace("Transaction failed, will be removed", "hash", tx.Hash(), "err", err)
+			env.failedTxs = append(env.failedTxs, tx)
+			txs.Pop()
 		}
 	}
 
diff --git a/tests/state_test_util.go b/tests/state_test_util.go
index 81f49efa5..c1892cdcc 100644
--- a/tests/state_test_util.go
+++ b/tests/state_test_util.go
@@ -214,7 +214,7 @@ func RunState(chainConfig *params.ChainConfig, statedb *state.StateDB, env, tx m
 	snapshot := statedb.Snapshot()
 
 	ret, gasUsed, err := core.ApplyMessage(environment, msg, gaspool)
-	if core.IsNonceErr(err) || core.IsInvalidTxErr(err) || core.IsGasLimitErr(err) {
+	if err != nil {
 		statedb.RevertToSnapshot(snapshot)
 	}
 	statedb.Commit(chainConfig.IsEIP158(environment.Context.BlockNumber))