Script to covert a file of GeoJSON to Esri JSON in NodeJS utilizing the `arcgis-to-geojson-utils` package.

geojson-to-esri-json-polygons-nodejs.js

const esriUtils = require('@esri/arcgis-to-geojson-utils');
const fs = require('fs');

const inGeoJson = JSON.parse(fs.readFileSync('FILENAME.json', 'utf8'));

console.log('inGeoJson', inGeoJson);

const result = esriUtils.geojsonToArcGIS(inGeoJson);

let outFeatureSet = { 
  "displayFieldName": "", 
  "fieldAliases": {}, 
  "geometryType": "esriGeometryPolygon", 
  "fields": [], 
  "spatialReference": { "wkid": 4326 }, 
  "features": result
};

// console.log('result', JSON.stringify(outFeatureSet));
fs.writeFile('out.json', JSON.stringify(outFeatureSet), 'utf8', function (err) {
  if (err) {
      return console.log(err);
  }

  console.log("The file was saved!");
});