Remove potentional nilpointer dereference

executor/extension/tracker/db_logger.go

@@ -43,8 +43,8 @@ func makeDbLogger[T any](cfg *utils.Config, log logger.Logger) executor.Extensio
 	}
 }
 
-// PreRun creates a logging file and starts the logging thread.
-func (l *dbLogger[T]) PreRun(_ executor.State[T], ctx *executor.Context) error {
+// PreRun creates a logging file
+func (l *dbLogger[T]) PreRun(executor.State[T], *executor.Context) error {
 	var err error
 	l.file, err = os.Create(l.cfg.DbLogging)
 	if err != nil {
@@ -56,7 +56,6 @@ func (l *dbLogger[T]) PreRun(_ executor.State[T], ctx *executor.Context) error {
 	l.wg.Add(1)
 	go l.doLogging()
 
-	ctx.State = proxy.NewLoggerProxy(ctx.State, l.log, l.input)
 	return nil
 }
 

executor/extension/tracker/db_logger_test.go

@@ -70,6 +70,11 @@ func TestDbLoggerExtension_LoggingHappens(t *testing.T) {
 		t.Fatalf("pre-run returned err; %v", err)
 	}
 
+	err = ext.PreTransaction(executor.State[any]{}, ctx)
+	if err != nil {
+		t.Fatalf("pre-transaction returned err; %v", err)
+	}
+
 	balance := new(big.Int).SetInt64(10)
 
 	beginBlock := fmt.Sprintf("BeginBlock, %v", 1)
@@ -167,14 +172,16 @@ func TestDbLoggerExtension_PreTransactionDoesNotCreateNewLoggerProxy(t *testing.
 
 	ext := MakeDbLogger[any](cfg)
 
-	// PreRun assigns LoggerProxy onto ctx.State, hence PreTransaction does no create new
-	err := ext.PreRun(executor.State[any]{}, ctx)
+	// first call PreTransaction to assign the proxy
+	err := ext.PreTransaction(executor.State[any]{}, ctx)
 	if err != nil {
-		t.Fatalf("pre-run failed; %v", err)
+		t.Fatalf("pre-transaction failed; %v", err)
 	}
 
+	// save original state to make sure next call to PreTransaction will not have changed the ctx.State
 	originalDb := ctx.State
 
+	// then make sure it is not re-assigned again
 	err = ext.PreTransaction(executor.State[any]{}, ctx)
 	if err != nil {
 		t.Fatalf("pre-transaction failed; %v", err)
@@ -184,3 +191,26 @@ func TestDbLoggerExtension_PreTransactionDoesNotCreateNewLoggerProxy(t *testing.
 		t.Fatal("db must not be be changed!")
 	}
 }
+
+func TestDbLoggerExtension_PreRunDoesNotCreateNewLoggerProxy(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	db := state.NewMockStateDB(ctrl)
+
+	cfg := &utils.Config{}
+	cfg.DbLogging = t.TempDir() + "test-log"
+	cfg.LogLevel = "critical"
+
+	ctx := new(executor.Context)
+	ctx.State = db
+
+	ext := MakeDbLogger[any](cfg)
+
+	err := ext.PreRun(executor.State[any]{}, ctx)
+	if err != nil {
+		t.Fatalf("pre-transaction failed; %v", err)
+	}
+
+	if _, ok := ctx.State.(*proxy.LoggingStateDb); ok {
+		t.Fatal("db must not be of type LoggingStateDb!")
+	}
+}