accounts/abi/bind/backends: remove nil and remote backends

The remote backend is superseded by ethclient.

The nil backend's stated purpose was to enable testing of
accounts/abi/bind. None of its methods actually worked. A much simpler
way to get a crashing backend is to simply pass nil as the backend. With
a one-line change to the generator (removing two explicit interface
assertions), passing nil actually works.

Removing these backends means that less changes are required later.

4 files changed, 10 insertions, 203 deletions

diff --git a/accounts/abi/bind/backends/nil.go b/accounts/abi/bind/backends/nil.go
deleted file mode 100644
index 54b222f1f..000000000
--- a/accounts/abi/bind/backends/nil.go
+++ /dev/null
@@ -1,57 +0,0 @@
-// Copyright 2016 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 backends
-
-import (
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/accounts/abi/bind"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/types"
-	"golang.org/x/net/context"
-)
-
-// This nil assignment ensures compile time that nilBackend implements bind.ContractBackend.
-var _ bind.ContractBackend = (*nilBackend)(nil)
-
-// nilBackend implements bind.ContractBackend, but panics on any method call.
-// Its sole purpose is to support the binding tests to construct the generated
-// wrappers without calling any methods on them.
-type nilBackend struct{}
-
-func (*nilBackend) ContractCall(context.Context, common.Address, []byte, bool) ([]byte, error) {
-	panic("not implemented")
-}
-func (*nilBackend) EstimateGasLimit(context.Context, common.Address, *common.Address, *big.Int, []byte) (*big.Int, error) {
-	panic("not implemented")
-}
-func (*nilBackend) HasCode(context.Context, common.Address, bool) (bool, error) {
-	panic("not implemented")
-}
-func (*nilBackend) SuggestGasPrice(context.Context) (*big.Int, error) { panic("not implemented") }
-func (*nilBackend) PendingAccountNonce(context.Context, common.Address) (uint64, error) {
-	panic("not implemented")
-}
-func (*nilBackend) SendTransaction(context.Context, *types.Transaction) error {
-	panic("not implemented")
-}
-
-// NewNilBackend creates a new binding backend that can be used for instantiation
-// but will panic on any invocation. Its sole purpose is to help testing.
-func NewNilBackend() bind.ContractBackend {
-	return new(nilBackend)
-}
diff --git a/accounts/abi/bind/backends/remote.go b/accounts/abi/bind/backends/remote.go
deleted file mode 100644
index 58edd791a..000000000
--- a/accounts/abi/bind/backends/remote.go
+++ /dev/null
@@ -1,136 +0,0 @@
-// Copyright 2016 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 backends
-
-import (
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/accounts/abi/bind"
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/ethereum/go-ethereum/rpc"
-	"golang.org/x/net/context"
-)
-
-// This nil assignment ensures compile time that rpcBackend implements bind.ContractBackend.
-var _ bind.ContractBackend = (*rpcBackend)(nil)
-
-// rpcBackend implements bind.ContractBackend, and acts as the data provider to
-// Ethereum contracts bound to Go structs. It uses an RPC connection to delegate
-// all its functionality.
-type rpcBackend struct {
-	client *rpc.Client // RPC client connection to interact with an API server
-}
-
-// NewRPCBackend creates a new binding backend to an RPC provider that can be
-// used to interact with remote contracts.
-func NewRPCBackend(client *rpc.Client) bind.ContractBackend {
-	return &rpcBackend{client: client}
-}
-
-// HasCode implements ContractVerifier.HasCode by retrieving any code associated
-// with the contract from the remote node, and checking its size.
-func (b *rpcBackend) HasCode(ctx context.Context, contract common.Address, pending bool) (bool, error) {
-	block := "latest"
-	if pending {
-		block = "pending"
-	}
-	var hex string
-	err := b.client.CallContext(ctx, &hex, "eth_getCode", contract, block)
-	if err != nil {
-		return false, err
-	}
-	return len(common.FromHex(hex)) > 0, nil
-}
-
-// ContractCall implements ContractCaller.ContractCall, delegating the execution of
-// a contract call to the remote node, returning the reply to for local processing.
-func (b *rpcBackend) ContractCall(ctx context.Context, contract common.Address, data []byte, pending bool) ([]byte, error) {
-	args := struct {
-		To   common.Address `json:"to"`
-		Data string         `json:"data"`
-	}{
-		To:   contract,
-		Data: common.ToHex(data),
-	}
-	block := "latest"
-	if pending {
-		block = "pending"
-	}
-	var hex string
-	err := b.client.CallContext(ctx, &hex, "eth_call", args, block)
-	if err != nil {
-		return nil, err
-	}
-	return common.FromHex(hex), nil
-
-}
-
-// PendingAccountNonce implements ContractTransactor.PendingAccountNonce, delegating
-// the current account nonce retrieval to the remote node.
-func (b *rpcBackend) PendingAccountNonce(ctx context.Context, account common.Address) (uint64, error) {
-	var hex rpc.HexNumber
-	err := b.client.CallContext(ctx, &hex, "eth_getTransactionCount", account.Hex(), "pending")
-	if err != nil {
-		return 0, err
-	}
-	return hex.Uint64(), nil
-}
-
-// SuggestGasPrice implements ContractTransactor.SuggestGasPrice, delegating the
-// gas price oracle request to the remote node.
-func (b *rpcBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
-	var hex rpc.HexNumber
-	if err := b.client.CallContext(ctx, &hex, "eth_gasPrice"); err != nil {
-		return nil, err
-	}
-	return (*big.Int)(&hex), nil
-}
-
-// EstimateGasLimit implements ContractTransactor.EstimateGasLimit, delegating
-// the gas estimation to the remote node.
-func (b *rpcBackend) EstimateGasLimit(ctx context.Context, sender common.Address, contract *common.Address, value *big.Int, data []byte) (*big.Int, error) {
-	args := struct {
-		From  common.Address  `json:"from"`
-		To    *common.Address `json:"to"`
-		Value *rpc.HexNumber  `json:"value"`
-		Data  string          `json:"data"`
-	}{
-		From:  sender,
-		To:    contract,
-		Data:  common.ToHex(data),
-		Value: rpc.NewHexNumber(value),
-	}
-	// Execute the RPC call and retrieve the response
-	var hex rpc.HexNumber
-	err := b.client.CallContext(ctx, &hex, "eth_estimateGas", args)
-	if err != nil {
-		return nil, err
-	}
-	return (*big.Int)(&hex), nil
-}
-
-// SendTransaction implements ContractTransactor.SendTransaction, delegating the
-// raw transaction injection to the remote node.
-func (b *rpcBackend) SendTransaction(ctx context.Context, tx *types.Transaction) error {
-	data, err := rlp.EncodeToBytes(tx)
-	if err != nil {
-		return err
-	}
-	return b.client.CallContext(ctx, nil, "eth_sendRawTransaction", common.ToHex(data))
-}
diff --git a/accounts/abi/bind/bind_test.go b/accounts/abi/bind/bind_test.go
index a80560821..67c09c3ad 100644
--- a/accounts/abi/bind/bind_test.go
+++ b/accounts/abi/bind/bind_test.go
@@ -44,13 +44,13 @@ var bindTests = []struct {
 		`606060405260068060106000396000f3606060405200`,
 		`[]`,
 		`
-			if b, err := NewEmpty(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewEmpty(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("combined binding (%v) nil or error (%v) not nil", b, nil)
 			}
-			if b, err := NewEmptyCaller(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewEmptyCaller(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("caller binding (%v) nil or error (%v) not nil", b, nil)
 			}
-			if b, err := NewEmptyTransactor(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewEmptyTransactor(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("transactor binding (%v) nil or error (%v) not nil", b, nil)
 			}
 		`,
@@ -62,7 +62,7 @@ var bindTests = []struct {
 		`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`,
 		`[{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"success","type":"bool"}],"type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"},{"name":"_extraData","type":"bytes"}],"name":"approveAndCall","outputs":[{"name":"success","type":"bool"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"},{"name":"","type":"address"}],"name":"spentAllowance","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"},{"name":"","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"inputs":[{"name":"initialSupply","type":"uint256"},{"name":"tokenName","type":"string"},{"name":"decimalUnits","type":"uint8"},{"name":"tokenSymbol","type":"string"}],"type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}]`,
 		`
-			if b, err := NewToken(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewToken(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("binding (%v) nil or error (%v) not nil", b, nil)
 			}
 		`,
@@ -73,7 +73,7 @@ var bindTests = []struct {
 		`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`,
 		`[{"constant":false,"inputs":[],"name":"checkGoalReached","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"deadline","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"beneficiary","outputs":[{"name":"","type":"address"}],"type":"function"},{"constant":true,"inputs":[],"name":"tokenReward","outputs":[{"name":"","type":"address"}],"type":"function"},{"constant":true,"inputs":[],"name":"fundingGoal","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"amountRaised","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"price","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"funders","outputs":[{"name":"addr","type":"address"},{"name":"amount","type":"uint256"}],"type":"function"},{"inputs":[{"name":"ifSuccessfulSendTo","type":"address"},{"name":"fundingGoalInEthers","type":"uint256"},{"name":"durationInMinutes","type":"uint256"},{"name":"etherCostOfEachToken","type":"uint256"},{"name":"addressOfTokenUsedAsReward","type":"address"}],"type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"backer","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"isContribution","type":"bool"}],"name":"FundTransfer","type":"event"}]`,
 		`
-			if b, err := NewCrowdsale(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewCrowdsale(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("binding (%v) nil or error (%v) not nil", b, nil)
 			}
 		`,
@@ -84,7 +84,7 @@ var bindTests = []struct {
 		`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`,
 		`[{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"proposals","outputs":[{"name":"recipient","type":"address"},{"name":"amount","type":"uint256"},{"name":"description","type":"string"},{"name":"votingDeadline","type":"uint256"},{"name":"executed","type":"bool"},{"name":"proposalPassed","type":"bool"},{"name":"numberOfVotes","type":"uint256"},{"name":"currentResult","type":"int256"},{"name":"proposalHash","type":"bytes32"}],"type":"function"},{"constant":false,"inputs":[{"name":"proposalNumber","type":"uint256"},{"name":"transactionBytecode","type":"bytes"}],"name":"executeProposal","outputs":[{"name":"result","type":"int256"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"memberId","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"numProposals","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"members","outputs":[{"name":"member","type":"address"},{"name":"canVote","type":"bool"},{"name":"name","type":"string"},{"name":"memberSince","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"debatingPeriodInMinutes","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"minimumQuorum","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"type":"function"},{"constant":false,"inputs":[{"name":"targetMember","type":"address"},{"name":"canVote","type":"bool"},{"name":"memberName","type":"string"}],"name":"changeMembership","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"majorityMargin","outputs":[{"name":"","type":"int256"}],"type":"function"},{"constant":false,"inputs":[{"name":"beneficiary","type":"address"},{"name":"etherAmount","type":"uint256"},{"name":"JobDescription","type":"string"},{"name":"transactionBytecode","type":"bytes"}],"name":"newProposal","outputs":[{"name":"proposalID","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"minimumQuorumForProposals","type":"uint256"},{"name":"minutesForDebate","type":"uint256"},{"name":"marginOfVotesForMajority","type":"int256"}],"name":"changeVotingRules","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"proposalNumber","type":"uint256"},{"name":"supportsProposal","type":"bool"},{"name":"justificationText","type":"string"}],"name":"vote","outputs":[{"name":"voteID","type":"uint256"}],"type":"function"},{"constant":true,"inputs":[{"name":"proposalNumber","type":"uint256"},{"name":"beneficiary","type":"address"},{"name":"etherAmount","type":"uint256"},{"name":"transactionBytecode","type":"bytes"}],"name":"checkProposalCode","outputs":[{"name":"codeChecksOut","type":"bool"}],"type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"type":"function"},{"inputs":[{"name":"minimumQuorumForProposals","type":"uint256"},{"name":"minutesForDebate","type":"uint256"},{"name":"marginOfVotesForMajority","type":"int256"},{"name":"congressLeader","type":"address"}],"type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"proposalID","type":"uint256"},{"indexed":false,"name":"recipient","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"description","type":"string"}],"name":"ProposalAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"proposalID","type":"uint256"},{"indexed":false,"name":"position","type":"bool"},{"indexed":false,"name":"voter","type":"address"},{"indexed":false,"name":"justification","type":"string"}],"name":"Voted","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"proposalID","type":"uint256"},{"indexed":false,"name":"result","type":"int256"},{"indexed":false,"name":"quorum","type":"uint256"},{"indexed":false,"name":"active","type":"bool"}],"name":"ProposalTallied","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"member","type":"address"},{"indexed":false,"name":"isMember","type":"bool"}],"name":"MembershipChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"minimumQuorum","type":"uint256"},{"indexed":false,"name":"debatingPeriodInMinutes","type":"uint256"},{"indexed":false,"name":"majorityMargin","type":"int256"}],"name":"ChangeOfRules","type":"event"}]`,
 		`
-			if b, err := NewDAO(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+			if b, err := NewDAO(common.Address{}, nil); b == nil || err != nil {
 				t.Fatalf("binding (%v) nil or error (%v) not nil", b, nil)
 			}
 		`,
@@ -102,7 +102,7 @@ var bindTests = []struct {
 				{"type":"function","name":"mixedInputs","constant":true,"inputs":[{"name":"","type":"string"},{"name":"str","type":"string"}],"outputs":[]}
 			]
 		`,
-		`if b, err := NewInputChecker(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+		`if b, err := NewInputChecker(common.Address{}, nil); b == nil || err != nil {
 			 t.Fatalf("binding (%v) nil or error (%v) not nil", b, nil)
 		 } else if false { // Don't run, just compile and test types
 			 var err error
@@ -130,7 +130,7 @@ var bindTests = []struct {
 				{"type":"function","name":"mixedOutputs","constant":true,"inputs":[],"outputs":[{"name":"","type":"string"},{"name":"str","type":"string"}]}
 			]
 		`,
-		`if b, err := NewOutputChecker(common.Address{}, backends.NewNilBackend()); b == nil || err != nil {
+		`if b, err := NewOutputChecker(common.Address{}, nil); b == nil || err != nil {
 			 t.Fatalf("binding (%v) nil or error (%v) not nil", b, nil)
 		 } else if false { // Don't run, just compile and test types
 			 var str1, str2 string
@@ -376,7 +376,7 @@ func TestBindings(t *testing.T) {
 		t.Skip("go sdk not found for testing")
 	}
 	// Skip the test if the go-ethereum sources are symlinked (https://github.com/golang/go/issues/14845)
-	linkTestCode := fmt.Sprintf("package linktest\nfunc CheckSymlinks(){\nfmt.Println(backends.NewNilBackend())\n}")
+	linkTestCode := fmt.Sprintf("package linktest\nfunc CheckSymlinks(){\nfmt.Println(backends.NewSimulatedBackend())\n}")
 	linkTestDeps, err := imports.Process("", []byte(linkTestCode), nil)
 	if err != nil {
 		t.Fatalf("failed check for goimports symlink bug: %v", err)
diff --git a/accounts/abi/bind/template.go b/accounts/abi/bind/template.go
index 72998bb6d..523122213 100644
--- a/accounts/abi/bind/template.go
+++ b/accounts/abi/bind/template.go
@@ -127,7 +127,7 @@ package {{.Package}}
 
 	// New{{.Type}} creates a new instance of {{.Type}}, bound to a specific deployed contract.
 	func New{{.Type}}(address common.Address, backend bind.ContractBackend) (*{{.Type}}, error) {
-	  contract, err := bind{{.Type}}(address, backend.(bind.ContractCaller), backend.(bind.ContractTransactor))
+	  contract, err := bind{{.Type}}(address, backend, backend)
 	  if err != nil {
 	    return nil, err
 	  }