Fix cannon trace provider tests and small changes

op-challenger/game/fault/trace/cannon/provider.go

@@ -48,12 +48,10 @@ type ProofGenerator interface {
 }
 
 type CannonTraceProvider struct {
-	logger         log.Logger
-	dir            string
-	prestate       string
-	generator      ProofGenerator
-	lastStepWriter LastStepWriter
-	lastStepReader LastStepReader
+	logger    log.Logger
+	dir       string
+	prestate  string
+	generator ProofGenerator
 
 	// lastStep stores the last step in the actual trace if known. 0 indicates unknown.
 	// Cached as an optimisation to avoid repeatedly attempting to execute beyond the end of the trace.
@@ -81,12 +79,10 @@ func NewTraceProvider(ctx context.Context, logger log.Logger, m CannonMetricer,
 
 func NewTraceProviderFromInputs(logger log.Logger, m CannonMetricer, cfg *config.Config, localInputs LocalGameInputs, dir string) *CannonTraceProvider {
 	return &CannonTraceProvider{
-		logger:         logger,
-		dir:            dir,
-		prestate:       cfg.CannonAbsolutePreState,
-		generator:      NewExecutor(logger, m, cfg, localInputs),
-		lastStepWriter: WriteLastStep,
-		lastStepReader: LoadLastStep,
+		logger:    logger,
+		dir:       dir,
+		prestate:  cfg.CannonAbsolutePreState,
+		generator: NewExecutor(logger, m, cfg, localInputs),
 	}
 }
 
@@ -152,7 +148,7 @@ func (p *CannonTraceProvider) loadProof(ctx context.Context, i uint64) (*proofDa
 	}
 	// Attempt to read the last step from disk cache
 	if p.lastProof == nil && p.lastStep == 0 {
-		step, err := p.lastStepReader(p.dir)
+		step, err := ReadLastStep(p.dir)
 		if err != nil {
 			p.logger.Warn("Failed to read last step from disk cache", "err", err)
 		} else {
@@ -188,7 +184,7 @@ func (p *CannonTraceProvider) loadProof(ctx context.Context, i uint64) (*proofDa
 				if err != nil {
 					return nil, fmt.Errorf("cannot hash witness: %w", err)
 				}
-				if err := p.lastStepWriter(p.dir, p.lastStep+1); err != nil {
+				if err := WriteLastStep(p.dir, p.lastStep+1); err != nil {
 					p.logger.Warn("Failed to write last step to disk cache", "step", p.lastStep)
 				}
 				proof := &proofData{
@@ -222,7 +218,7 @@ type diskStateCacheObj struct {
 	Step uint64 `json:"step"`
 }
 
-func LoadLastStep(dir string) (uint64, error) {
+func ReadLastStep(dir string) (uint64, error) {
 	state := diskStateCacheObj{}
 	file, err := ioutil.OpenDecompressed(filepath.Join(dir, diskStateCache))
 	if err != nil {

op-challenger/game/fault/trace/cannon/provider_test.go

@@ -65,8 +65,8 @@ func TestGet(t *testing.T) {
 }
 
 func TestGetStepData(t *testing.T) {
-	dataDir, prestate := setupTestData(t)
 	t.Run("ExistingProof", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		value, proof, data, err := provider.GetStepData(context.Background(), 0)
 		require.NoError(t, err)
@@ -80,6 +80,7 @@ func TestGetStepData(t *testing.T) {
 	})
 
 	t.Run("GenerateProof", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		generator.finalState = &mipsevm.State{
 			Memory: &mipsevm.Memory{},
@@ -105,6 +106,7 @@ func TestGetStepData(t *testing.T) {
 	})
 
 	t.Run("ProofAfterEndOfTrace", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		generator.finalState = &mipsevm.State{
 			Memory: &mipsevm.Memory{},
@@ -130,6 +132,7 @@ func TestGetStepData(t *testing.T) {
 	})
 
 	t.Run("ReadLastStepFromDisk", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, initGenerator := setupWithTestData(t, dataDir, prestate)
 		initGenerator.finalState = &mipsevm.State{
 			Memory: &mipsevm.Memory{},
@@ -146,7 +149,7 @@ func TestGetStepData(t *testing.T) {
 		}
 		_, _, _, err := provider.GetStepData(context.Background(), 7000)
 		require.NoError(t, err)
-		require.Contains(t, initGenerator.generated, 10, "should have tried to generate the proof")
+		require.Contains(t, initGenerator.generated, 7000, "should have tried to generate the proof")
 
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		generator.finalState = &mipsevm.State{
@@ -173,13 +176,15 @@ func TestGetStepData(t *testing.T) {
 	})
 
 	t.Run("MissingStateData", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		_, _, _, err := provider.GetStepData(context.Background(), 1)
 		require.ErrorContains(t, err, "missing state data")
 		require.Empty(t, generator.generated)
 	})
 
 	t.Run("IgnoreUnknownFields", func(t *testing.T) {
+		dataDir, prestate := setupTestData(t)
 		provider, generator := setupWithTestData(t, dataDir, prestate)
 		value, proof, data, err := provider.GetStepData(context.Background(), 2)
 		require.NoError(t, err)
@@ -261,12 +266,10 @@ func setupTestData(t *testing.T) (string, string) {
 func setupWithTestData(t *testing.T, dataDir string, prestate string) (*CannonTraceProvider, *stubGenerator) {
 	generator := &stubGenerator{}
 	return &CannonTraceProvider{
-		logger:         testlog.Logger(t, log.LvlInfo),
-		dir:            dataDir,
-		generator:      generator,
-		prestate:       filepath.Join(dataDir, prestate),
-		lastStepReader: LoadLastStep,
-		lastStepWriter: WriteLastStep,
+		logger:    testlog.Logger(t, log.LvlInfo),
+		dir:       dataDir,
+		generator: generator,
+		prestate:  filepath.Join(dataDir, prestate),
 	}, generator
 }