👌 [backend/eth/channel|sub] Apply review fixes.

Signed-off-by: Oliver Tale-Yazdi <oliver@perun.network>

Author: ggwpez

backend/ethereum/bindings/abi.go

@@ -15,6 +15,7 @@
 package bindings
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/accounts/abi"
@@ -27,37 +28,69 @@ import (
 	"perun.network/go-perun/backend/ethereum/bindings/trivialapp"
 )
 
-// This file contains all the parsed ABI definitions of our contracts.
+// ABI contains all the parsed ABI definitions of our contracts.
 // Use it together with `bind.NewBoundContract` to create a bound contract.
+var ABI = struct {
+	// ERC20Token is the parsed ABI definition of contract ERC20Token.
+	ERC20Token abi.ABI
+	// Adjudicator is the parsed ABI definition of contract Adjudicator.
+	Adjudicator abi.ABI
+	// AssetHolder is the parsed ABI definition of contract AssetHolder.
+	AssetHolder abi.ABI
+	// ETHAssetHolder is the parsed ABI definition of contract ETHAssetHolder.
+	ETHAssetHolder abi.ABI
+	// ERC20AssetHolder is the parsed ABI definition of contract ERC20AssetHolder.
+	ERC20AssetHolder abi.ABI
+	// TrivialApp is the parsed ABI definition of contract TrivialApp.
+	TrivialApp abi.ABI
+}{}
 
-var (
-	// ERC20TokenABI is the parsed ABI definition of contract ERC20Token.
-	ERC20TokenABI abi.ABI
-	// AdjudicatorABI is the parsed ABI definition of contract Adjudicator.
-	AdjudicatorABI abi.ABI
-	// AssetHolderABI is the parsed ABI definition of contract AssetHolder.
-	AssetHolderABI abi.ABI
-	// ETHAssetHolderABI is the parsed ABI definition of contract ETHAssetHolder.
-	ETHAssetHolderABI abi.ABI
-	// ERC20AssetHolderABI is the parsed ABI definition of contract ERC20AssetHolder.
-	ERC20AssetHolderABI abi.ABI
-	// TrivialAppABI is the parsed ABI definition of contract TrivialApp.
-	TrivialAppABI abi.ABI
-)
+// Events contains the event names for specific events.
+var Events = struct {
+	// AdjChannelUpdate is the ChannelUpdate event of the Adjudicator contract.
+	AdjChannelUpdate string
+	// AhDeposited is the Deposited event of the Assetholder contract.
+	AhDeposited string
+	// AhWithdrawn is the Withdrawn event of the Assetholder contract.
+	AhWithdrawn string
+	// ERC20Approval is the Approval event of the ERC20Token contract.
+	ERC20Approval string
+}{}
 
 func init() {
-	parseABI := func(raw string) abi.ABI {
+	parseABIs()
+	extractEvents()
+}
+
+func parseABIs() {
+	parse := func(raw string) abi.ABI {
 		abi, err := abi.JSON(strings.NewReader(raw))
 		if err != nil {
 			panic(err)
 		}
 		return abi
 	}
 
-	ERC20TokenABI = parseABI(peruntoken.ERC20ABI)
-	AdjudicatorABI = parseABI(adjudicator.AdjudicatorABI)
-	AssetHolderABI = parseABI(assetholder.AssetHolderABI)
-	ETHAssetHolderABI = parseABI(assetholdereth.AssetHolderETHABI)
-	ERC20AssetHolderABI = parseABI(assetholdererc20.AssetHolderERC20ABI)
-	TrivialAppABI = parseABI(trivialapp.TrivialAppABI)
+	ABI.ERC20Token = parse(peruntoken.ERC20ABI)
+	ABI.Adjudicator = parse(adjudicator.AdjudicatorABI)
+	ABI.AssetHolder = parse(assetholder.AssetHolderABI)
+	ABI.ETHAssetHolder = parse(assetholdereth.AssetHolderETHABI)
+	ABI.ERC20AssetHolder = parse(assetholdererc20.AssetHolderERC20ABI)
+	ABI.TrivialApp = parse(trivialapp.TrivialAppABI)
+}
+
+// extractEvents sets the event names and panics if any event does not exist.
+func extractEvents() {
+	extract := func(abi abi.ABI, eName string) string {
+		e, ok := abi.Events[eName]
+		if !ok {
+			panic(fmt.Sprintf("Event '%s' not found.", eName))
+		}
+		return e.Name
+	}
+
+	Events.AdjChannelUpdate = extract(ABI.Adjudicator, "ChannelUpdate")
+	Events.AhDeposited = extract(ABI.AssetHolder, "Deposited")
+	Events.AhWithdrawn = extract(ABI.AssetHolder, "Withdrawn")
+	Events.ERC20Approval = extract(ABI.ERC20Token, "Approval")
 }

backend/ethereum/channel/adjudicator.go

@@ -59,7 +59,7 @@ func NewAdjudicator(backend ContractBackend, contract common.Address, receiver c
 	if err != nil {
 		panic("Could not create a new instance of adjudicator")
 	}
-	bound := bind.NewBoundContract(contract, bindings.AdjudicatorABI, backend, backend, backend)
+	bound := bind.NewBoundContract(contract, bindings.ABI.Adjudicator, backend, backend, backend)
 	return &Adjudicator{
 		ContractBackend: backend,
 		contract:        contr,

backend/ethereum/channel/conclude.go

@@ -21,6 +21,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/pkg/errors"
 
+	"perun.network/go-perun/backend/ethereum/bindings"
 	"perun.network/go-perun/backend/ethereum/bindings/adjudicator"
 	cherrors "perun.network/go-perun/backend/ethereum/channel/errors"
 	"perun.network/go-perun/backend/ethereum/subscription"
@@ -79,11 +80,9 @@ func (a *Adjudicator) ensureConcluded(ctx context.Context, req channel.Adjudicat
 
 	// No conclude event found in the past, send transaction.
 	if req.Tx.IsFinal {
-		err = cherrors.CheckIsChainNotReachableError(a.callConcludeFinal(ctx, req))
-		err = errors.WithMessage(err, "calling concludeFinal")
+		err = errors.WithMessage(a.callConcludeFinal(ctx, req), "calling concludeFinal")
 	} else {
-		err = cherrors.CheckIsChainNotReachableError(a.callConclude(ctx, req, subStates))
-		err = errors.WithMessage(err, "calling conclude")
+		err = errors.WithMessage(a.callConclude(ctx, req, subStates), "calling conclude")
 	}
 	if IsErrTxFailed(err) {
 		a.log.Warn("Calling conclude(Final) failed, waiting for event anyways...")
@@ -112,7 +111,7 @@ func (a *Adjudicator) ensureConcluded(ctx context.Context, req channel.Adjudicat
 func updateEventType(channelID [32]byte) subscription.EventFactory {
 	return func() *subscription.Event {
 		return &subscription.Event{
-			Name: "ChannelUpdate",
+			Name: bindings.Events.AdjChannelUpdate,
 			Data: new(adjudicator.AdjudicatorChannelUpdate),
 			// In the best case we could already filter for 'Concluded' phase only here.
 			Filter: [][]interface{}{{channelID}},

backend/ethereum/channel/funder.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/pkg/errors"
 
+	"perun.network/go-perun/backend/ethereum/bindings"
 	"perun.network/go-perun/backend/ethereum/bindings/assetholder"
 	"perun.network/go-perun/backend/ethereum/subscription"
 	"perun.network/go-perun/backend/ethereum/wallet"
@@ -240,7 +241,7 @@ func (f *Funder) depositedSub(ctx context.Context, contract *bind.BoundContract,
 	}
 	event := func() *subscription.Event {
 		return &subscription.Event{
-			Name:   "Deposited",
+			Name:   bindings.Events.AhDeposited,
 			Data:   new(assetholder.AssetHolderDeposited),
 			Filter: [][]interface{}{filter},
 		}

backend/ethereum/channel/subscription.go

@@ -23,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
 
+	"perun.network/go-perun/backend/ethereum/bindings"
 	"perun.network/go-perun/backend/ethereum/bindings/adjudicator"
 	cherrors "perun.network/go-perun/backend/ethereum/channel/errors"
 	"perun.network/go-perun/backend/ethereum/subscription"
@@ -36,7 +37,7 @@ func (a *Adjudicator) Subscribe(ctx context.Context, params *channel.Params) (ch
 	events := make(chan *subscription.Event, 10)
 	eFact := func() *subscription.Event {
 		return &subscription.Event{
-			Name:   "ChannelUpdate",
+			Name:   bindings.Events.AdjChannelUpdate,
 			Data:   new(adjudicator.AdjudicatorChannelUpdate),
 			Filter: [][]interface{}{{params.ID()}},
 		}

backend/ethereum/channel/withdraw.go

@@ -105,7 +105,7 @@ func (a *Adjudicator) ensureWithdrawn(ctx context.Context, req channel.Adjudicat
 func withdrawnEventType(fundingID [32]byte) subscription.EventFactory {
 	return func() *subscription.Event {
 		return &subscription.Event{
-			Name:   "Withdrawn",
+			Name:   bindings.Events.AhWithdrawn,
 			Data:   new(assetholder.AssetHolderWithdrawn),
 			Filter: [][]interface{}{{fundingID}},
 		}
@@ -119,7 +119,7 @@ func bindAssetHolder(cb ContractBackend, asset channel.Asset, assetIndex channel
 	if err != nil {
 		log.Panic("Invalid AssetHolder ABI definition.")
 	}
-	contract := bind.NewBoundContract(assetAddr, bindings.AssetHolderABI, cb, cb, cb)
+	contract := bind.NewBoundContract(assetAddr, bindings.ABI.AssetHolder, cb, cb, cb)
 	return assetHolder{ctr, &assetAddr, contract, assetIndex}
 }
 

backend/ethereum/subscription/eventsub_test.go

@@ -89,13 +89,13 @@ func TestEventSub(t *testing.T) {
 	sink := make(chan *subscription.Event, 10)
 	eFact := func() *subscription.Event {
 		return &subscription.Event{
-			Name: "Approval",
+			Name: bindings.Events.ERC20Approval,
 			Data: new(peruntoken.ERC20Approval),
 		}
 	}
 	// Setup the event sub after some events have been sent.
 	<-waitSent
-	contract := bind.NewBoundContract(tokenAddr, bindings.ERC20TokenABI, cb, cb, cb)
+	contract := bind.NewBoundContract(tokenAddr, bindings.ABI.ERC20Token, cb, cb, cb)
 	sub, err := subscription.NewEventSub(ctx, cb, contract, eFact, 10000)
 	require.NoError(t, err)
 	go ct.Stage("sub", func(t pkgtest.ConcT) {
@@ -171,12 +171,12 @@ func TestEventSub_Filter(t *testing.T) {
 	sink := make(chan *subscription.Event, 1)
 	eFact := func() *subscription.Event {
 		return &subscription.Event{
-			Name:   "Deposited",
+			Name:   bindings.Events.AhDeposited,
 			Data:   new(assetholder.AssetHolderDeposited),
 			Filter: [][]interface{}{Filter},
 		}
 	}
-	contract := bind.NewBoundContract(ahAddr, bindings.AssetHolderABI, cb, cb, cb)
+	contract := bind.NewBoundContract(ahAddr, bindings.ABI.AssetHolder, cb, cb, cb)
 	sub, err := subscription.NewEventSub(ctx, cb, contract, eFact, 100)
 	require.NoError(t, err)
 	go ct.Stage("sub", func(t pkgtest.ConcT) {