Return execution time

server.js

@@ -97,6 +97,7 @@ async function executeUserCode(
   funcName = "userFunc"
 ) {
   const logs = [];
+  const startTime = process.hrtime();
   const vm = createVm(
     logs,
     requestObject,
@@ -118,21 +119,27 @@ async function executeUserCode(
     const result = await Promise.resolve(
       userFn(requestObject, vm.sandbox.environment)
     );
+    const endTime = process.hrtime(startTime);
+    const executionTime = (endTime[0] * 1e9 + endTime[1]) / 1e6; // in milliseconds
     return {
       status: States.SUCCESS,
       result,
       logs,
       environment: vm.sandbox.environment,
+      execution_time: executionTime,
     };
   } catch (err) {
     const status = /timed out/i.test(err.message)
       ? States.TIMEOUT
       : States.SCRIPT_ERROR;
+    const endTime = process.hrtime(startTime);
+    const executionTime = (endTime[0] * 1e9 + endTime[1]) / 1e6; // in milliseconds
     return {
       status,
       result: err.message ?? err,
       logs,
       environment: vm.sandbox.environment,
+      execution_time: executionTime,
     };
   }
 }