vm: skip _runStepHook method if no step event listener (#1676)

Co-authored-by: Holger Drewes <Holger.Drewes@gmail.com>
ethereumjs · Feb 1, 2022 · b224247 · b224247
1 parent 06bdad5
commit b224247
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/packages/vm/src/evm/interpreter.ts b/packages/vm/src/evm/interpreter.ts
@@ -150,7 +150,11 @@ export default class Interpreter {
       await dynamicGasHandler(this._runState, gas, this._vm._common)
     }
 
-    await this._runStepHook(gas, gasLimitClone)
+    if (this._vm.listenerCount('step') > 0) {
+      // Only run this stepHook function if there is an event listener (e.g. test runner)
+      // since its sole purpose is to emit the step event which is not used anywhere else
+      await this._runStepHook(gas, gasLimitClone)
+    }
 
     // Check for invalid opcode
     if (opInfo.name === 'INVALID') {