Add detail to TODO and reduce duplication in e2e helper.

op-challenger/game/fault/trace/outputs/output_cannon.go

@@ -17,7 +17,7 @@ func NewOutputCannonTraceAccessor(ctx context.Context, logger log.Logger, rollup
 	}
 
 	cannonCreator := func(ctx context.Context, pre types.Claim, post types.Claim) (types.TraceProvider, error) {
-		// TODO(client-pod#43): Implement this.
+		// TODO(client-pod#43): Actually create the cannon trace provider for the trace between the given claims.
 		return nil, errors.New("not implemented")
 	}
 

op-e2e/e2eutils/disputegame/helper.go

@@ -103,8 +103,7 @@ func NewFactoryHelper(t *testing.T, ctx context.Context, deployments *genesis.L1
 }
 
 func (h *FactoryHelper) StartAlphabetGame(ctx context.Context, claimedAlphabet string) *AlphabetGameHelper {
-	l2BlockNumber := h.waitForProposals(ctx)
-	l1Head := h.checkpointL1Block(ctx)
+	extraData, _, _ := h.createDisputeGameExtraData(ctx)
 
 	ctx, cancel := context.WithTimeout(ctx, 2*time.Minute)
 	defer cancel()
@@ -113,9 +112,6 @@ func (h *FactoryHelper) StartAlphabetGame(ctx context.Context, claimedAlphabet s
 	pos := faultTypes.NewPosition(alphabetGameDepth, lastAlphabetTraceIndex)
 	rootClaim, err := trace.Get(ctx, pos)
 	h.require.NoError(err, "get root claim")
-	extraData := make([]byte, 64)
-	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
-	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
 	tx, err := transactions.PadGasEstimate(h.opts, 2, func(opts *bind.TransactOpts) (*types.Transaction, error) {
 		return h.factory.Create(opts, alphabetGameType, rootClaim, extraData)
 	})
@@ -144,15 +140,11 @@ func (h *FactoryHelper) StartAlphabetGame(ctx context.Context, claimedAlphabet s
 }
 
 func (h *FactoryHelper) StartOutputCannonGame(ctx context.Context, rollupEndpoint string, rootClaim common.Hash) *OutputCannonGameHelper {
-	l2BlockNumber := h.waitForProposals(ctx)
-	l1Head := h.checkpointL1Block(ctx)
+	extraData, _, _ := h.createDisputeGameExtraData(ctx)
 
 	ctx, cancel := context.WithTimeout(ctx, 1*time.Minute)
 	defer cancel()
 
-	extraData := make([]byte, 64)
-	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
-	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
 	tx, err := transactions.PadGasEstimate(h.opts, 2, func(opts *bind.TransactOpts) (*types.Transaction, error) {
 		return h.factory.Create(opts, outputCannonGameType, rootClaim, extraData)
 	})
@@ -184,12 +176,12 @@ func (h *FactoryHelper) StartOutputCannonGame(ctx context.Context, rollupEndpoin
 }
 
 func (h *FactoryHelper) StartCannonGame(ctx context.Context, rootClaim common.Hash) *CannonGameHelper {
-	l2BlockNumber, l1Head := h.prepareCannonGame(ctx)
-	return h.createCannonGame(ctx, l2BlockNumber, l1Head, rootClaim)
+	extraData, _, _ := h.createDisputeGameExtraData(ctx)
+	return h.createCannonGame(ctx, rootClaim, extraData)
 }
 
 func (h *FactoryHelper) StartCannonGameWithCorrectRoot(ctx context.Context, rollupCfg *rollup.Config, l2Genesis *core.Genesis, l1Endpoint string, l2Endpoint string, options ...challenger.Option) (*CannonGameHelper, *HonestHelper) {
-	l2BlockNumber, l1Head := h.prepareCannonGame(ctx)
+	extraData, l1Head, l2BlockNumber := h.createDisputeGameExtraData(ctx)
 	challengerOpts := []challenger.Option{
 		challenger.WithCannon(h.t, rollupCfg, l2Genesis, l2Endpoint),
 		challenger.WithFactoryAddress(h.factoryAddr),
@@ -243,7 +235,7 @@ func (h *FactoryHelper) StartCannonGameWithCorrectRoot(ctx context.Context, roll
 	// Otherwise creating the game will fail
 	rootClaim[0] = mipsevm.VMStatusInvalid
 
-	game := h.createCannonGame(ctx, l2BlockNumber, l1Head, rootClaim)
+	game := h.createCannonGame(ctx, rootClaim, extraData)
 	correctMaxDepth := game.MaxDepth(ctx)
 	provider.SetMaxDepth(uint64(correctMaxDepth))
 	honestHelper := &HonestHelper{
@@ -255,13 +247,10 @@ func (h *FactoryHelper) StartCannonGameWithCorrectRoot(ctx context.Context, roll
 	return game, honestHelper
 }
 
-func (h *FactoryHelper) createCannonGame(ctx context.Context, l2BlockNumber uint64, l1Head *big.Int, rootClaim common.Hash) *CannonGameHelper {
+func (h *FactoryHelper) createCannonGame(ctx context.Context, rootClaim common.Hash, extraData []byte) *CannonGameHelper {
 	ctx, cancel := context.WithTimeout(ctx, 1*time.Minute)
 	defer cancel()
 
-	extraData := make([]byte, 64)
-	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
-	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
 	tx, err := transactions.PadGasEstimate(h.opts, 2, func(opts *bind.TransactOpts) (*types.Transaction, error) {
 		return h.factory.Create(opts, cannonGameType, rootClaim, extraData)
 	})
@@ -287,6 +276,15 @@ func (h *FactoryHelper) createCannonGame(ctx context.Context, l2BlockNumber uint
 	}
 }
 
+func (h *FactoryHelper) createDisputeGameExtraData(ctx context.Context) (extraData []byte, l1Head *big.Int, l2BlockNumber uint64) {
+	l2BlockNumber = h.waitForProposals(ctx)
+	l1Head = h.checkpointL1Block(ctx)
+	extraData = make([]byte, 64)
+	binary.BigEndian.PutUint64(extraData[24:], l2BlockNumber)
+	binary.BigEndian.PutUint64(extraData[56:], l1Head.Uint64())
+	return
+}
+
 func (h *FactoryHelper) StartChallenger(ctx context.Context, l1Endpoint string, name string, options ...challenger.Option) *challenger.Helper {
 	opts := []challenger.Option{
 		challenger.WithFactoryAddress(h.factoryAddr),
@@ -299,12 +297,6 @@ func (h *FactoryHelper) StartChallenger(ctx context.Context, l1Endpoint string,
 	return c
 }
 
-func (h *FactoryHelper) prepareCannonGame(ctx context.Context) (uint64, *big.Int) {
-	l2BlockNumber := h.waitForProposals(ctx)
-	l1Head := h.checkpointL1Block(ctx)
-	return l2BlockNumber, l1Head
-}
-
 // waitForProposals waits until there are at least two proposals in the output oracle
 // This is the minimum required for creating a game.
 // Returns the l2 block number of the latest available proposal