op-challenger: Fix prestate loading for asterisc in run-trace (#11363)

op-challenger/runner/factory.go

@@ -3,6 +3,8 @@ package runner
 import (
 	"errors"
 	"fmt"
+	"net/url"
+	"path/filepath"
 
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/trace/asterisc"
@@ -19,24 +21,39 @@ func createTraceProvider(
 	logger log.Logger,
 	m vm.Metricer,
 	cfg *config.Config,
-	prestateSource prestates.PrestateSource,
 	prestateHash common.Hash,
 	traceType types.TraceType,
 	localInputs utils.LocalGameInputs,
 	dir string,
 ) (types.TraceProvider, error) {
-	prestate, err := prestateSource.PrestatePath(prestateHash)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get prestate %v: %w", prestateHash, err)
-	}
-
 	switch traceType {
 	case types.TraceTypeCannon:
+		prestate, err := getPrestate(prestateHash, cfg.CannonAbsolutePreStateBaseURL, cfg.CannonAbsolutePreState, dir)
+		if err != nil {
+			return nil, err
+		}
 		prestateProvider := cannon.NewPrestateProvider(prestate)
 		return cannon.NewTraceProvider(logger, m, cfg.Cannon, prestateProvider, prestate, localInputs, dir, 42), nil
 	case types.TraceTypeAsterisc:
+		prestate, err := getPrestate(prestateHash, cfg.AsteriscAbsolutePreStateBaseURL, cfg.AsteriscAbsolutePreState, dir)
+		if err != nil {
+			return nil, err
+		}
 		prestateProvider := asterisc.NewPrestateProvider(prestate)
 		return asterisc.NewTraceProvider(logger, m, cfg.Asterisc, prestateProvider, prestate, localInputs, dir, 42), nil
 	}
 	return nil, errors.New("invalid trace type")
 }
+
+func getPrestate(prestateHash common.Hash, prestateBaseUrl *url.URL, prestatePath string, dataDir string) (string, error) {
+	prestateSource := prestates.NewPrestateSource(
+		prestateBaseUrl,
+		prestatePath,
+		filepath.Join(dataDir, "prestates"))
+
+	prestate, err := prestateSource.PrestatePath(prestateHash)
+	if err != nil {
+		return "", fmt.Errorf("failed to get prestate %v: %w", prestateHash, err)
+	}
+	return prestate, nil
+}

op-challenger/runner/runner.go

@@ -15,7 +15,6 @@ import (
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/contracts"
 	contractMetrics "github.com/ethereum-optimism/optimism/op-challenger/game/fault/contracts/metrics"
-	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/trace/prestates"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/trace/utils"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/trace/vm"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
@@ -130,12 +129,8 @@ func (r *Runner) runOnce(ctx context.Context, traceType types.TraceType, client
 	if err != nil {
 		return err
 	}
-	prestateSource := prestates.NewPrestateSource(
-		r.cfg.CannonAbsolutePreStateBaseURL,
-		r.cfg.CannonAbsolutePreState,
-		filepath.Join(dir, "prestates"))
 	logger := r.log.New("l1", localInputs.L1Head, "l2", localInputs.L2Head, "l2Block", localInputs.L2BlockNumber, "claim", localInputs.L2Claim, "type", traceType)
-	provider, err := createTraceProvider(logger, r.m, r.cfg, prestateSource, prestateHash, traceType, localInputs, dir)
+	provider, err := createTraceProvider(logger, r.m, r.cfg, prestateHash, traceType, localInputs, dir)
 	if err != nil {
 		return fmt.Errorf("failed to create trace provider: %w", err)
 	}
@@ -203,6 +198,9 @@ func (r *Runner) getPrestateHash(ctx context.Context, traceType types.TraceType,
 	if err != nil {
 		return common.Hash{}, fmt.Errorf("failed to load game impl: %w", err)
 	}
+	if gameImplAddr == (common.Address{}) {
+		return common.Hash{}, nil // No prestate is set, will only work if a single prestate is specified
+	}
 	gameImpl, err := contracts.NewFaultDisputeGameContract(ctx, r.m, gameImplAddr, caller)
 	if err != nil {
 		return common.Hash{}, fmt.Errorf("failed to create fault dispute game contract bindings for %v: %w", gameImplAddr, err)