NPM YARN NODE executing start time

1.js

console.log(1);

readme.md

• Download this as ZIP
• Run node process-bench.js "node 1.js"
• Run node process-bench.js "npm start"
• Run node process-bench.js "yarn start"

package.json

{
  "name": "start-time-demo",
  "version": "2.0.0",
  "main": "1.js",
  "scripts": {
    "start": "node 1.js"
  },
  "license": "MIT"
}

process-bench.js

const {exec} = require("child_process");

const command = process.argv[2];
if (!command) {
    console.log("[error] process.argv[2] is empty");
}

const startTime = Date.now();
const proc = exec(command);
console.log(`[exec start][${command}]`, Date.now() - startTime);

proc.stdout.on("data", data => {
    console.log("[data]", Date.now() - startTime);
    console.log(data);
});
proc.stdout.on("end", () => {
    console.log("[exec end]", Date.now() - startTime);
});

proc.on("error", e => console.log("[error][stdout]", e));
proc.stdout.on("error", e => console.log("[error]", e));