Incrementing buildNumber and versionCode in Expo projects

gistfile1.js

import JsonFileModule from '@expo/json-file';
import path from "path";
import { getConfig } from "@expo/config"


const JsonFile = JsonFileModule.default;

function getNewVersionCode(versionCode) {
	return versionCode ? versionCode + 1 : 1;
}


async function increment() {
	const projPath = path.resolve(
		process.cwd(),
		<path_to_proj>
	);

	let appConfig;
	try {
		appConfig = getConfig(projPath, { isPublicConfig: true });;
	} catch (error) {
		console.log(error.message);
	}

	const { pkg } = appConfig;


	if (!pkg.dependencies?.["expo"]) {
		console.log("This library works only for project using Expo");

		process.exit(1);
	}

	const versionCode = appConfig.exp.android.versionCode;
	const buildNumber = appConfig.exp.ios.buildNumber;

	const modifications = {
		android: { versionCode: getNewVersionCode(versionCode) }, ios: {
			buildNumber: getNewVersionCode(
				parseInt(buildNumber, 10),
			)
		}
	}


  // COPIED FROM EXPO SOURCE CODE
  //
	// Static with no dynamic config, this means we can append to the config automatically.
	let outputConfig;
	// If the config has an expo object (app.json) then append the options to that object.
	if (appConfig.rootConfig.expo) {
		outputConfig = {
			...appConfig.rootConfig,
			expo: { ...appConfig.rootConfig.expo, ...modifications },
		};
	} else {
		// Otherwise (app.config.json) just add the config modification to the top most level.
		outputConfig = { ...appConfig.rootConfig, ...modifications };
	}
	const appJsonFile = new JsonFile(appConfig.staticConfigPath);
	await appJsonFile.writeAsync(outputConfig, { json5: false });

}