gather-vars.js

/* eslint-disable */

const { execSync } = require('child_process');
const fs = require('fs');

const cmd = "grep -r --exclude-dir=node_modules 'process.env' ./"
const stdout = execSync(cmd, { encoding: 'UTF-8' });

// scrape envs from code
function getEnvs(input) {
	const arr = input.toString().split('\n');
    const newArr = [];
    arr.forEach((line) => {
      const re = new RegExp('(?<=\\bprocess.env.\\b)([A-Z]+[_]*)*', 'g');
	  const env = line.match(re);
	  if (env !== null)
      newArr.push(env);
    });
	var flatArray = newArr.reduce((a, b) => {
		return a.concat(b);
	});
	const unique = (envs) => envs.filter((a, b) => envs.indexOf(a) === b);
	const envs = unique(flatArray).sort();
	return envs
}

const envs = getEnvs(stdout);

// turn envs into object to be used by assert-envs
function envsToJson(array) {
    let obj = {}
    array.forEach((env) => {
      const entry = {};
      entry[`${env}`] = { 'required': true }
      Object.assign(obj, entry)
    });
	let json = { "env": obj }
    return json
  }

const envsObject = envsToJson(envs);

// create app.json file in the root
function writeJsonFile(object) {
	object = JSON.stringify(object);
	if (object !== undefined) {
		try {
			fs.writeFileSync('app.json', object, (err) => {
				if (err) throw err
				console.log('App.json written successfully');
			});
		} catch (err) {
			console.warn('Error writing env vars to app.json', err);
		}
	}
};

writeJsonFile(envsObject);