js

let options = {
  types: ["deprecation"],
  buffered: true,
};

let observer = new ReportingObserver((reports, observer) => {
  let firstReport = reports[0];
  console.log(firstReport.type); // deprecation
  console.log(firstReport.body.sourceFile); // the source file
  console.log(firstReport.body.lineNumber); // the line in that file
}, options);