SImple nodejs script that uses .env to generate environment.ts for Angular projects made to work on a lot of environments

env-vars.js

#! /usr/bin/env node

const dotenvParseVariables = require('dotenv-parse-variables');
const fs = require('fs');
const chalk = require('chalk');

const envVars = require('dotenv-safe').config({
  allowEmptyValues: true
});
const parsedVars = dotenvParseVariables(envVars.parsed);

function generateDef() {
  let props = Object.keys(parsedVars)
    .map(key => {
      return `${key}: ${typeof parsedVars[key]};`
    })
    .join(" ");

  const output = `export default class EnvConfig {
  ${props}
  }\n`;

  fs.writeFile('./src/environments/env-config.ts', output, (err) => {
    if (err) {
      console.log(err);
    }
    console.log('Angular environment definition file generated');
  });
}

function generateConst() {
  function stringify(obj_from_json) {
    if (typeof obj_from_json !== "object" || Array.isArray(obj_from_json)) {
      // not an object, stringify using native function
      return JSON.stringify(obj_from_json);
    }
    // Implements recursive object serialization according to JSON spec
    // but without quotes around the keys.
    let props = Object
      .keys(obj_from_json)
      .map(key => {
        return `${key}: ${stringify(obj_from_json[key])}`.replace(/"/g, '\'');
      })
      .join(",\n\t");
    return `${props}`;
  }

  const output = `
const environment = {
  /* tslint:disable */
  ${stringify(parsedVars)}
  /* tslint:enable */
};
export default environment;
`;

  fs.writeFile('./src/environments/environment.ts', output, (err) => {
    if (err) {
      console.log(err);
    }
    console.log(chalk.green('Angular environment file generated'));
  });
}

fs.mkdir('./src/environments', (err) => {
  generateConst();
});

//generateDef();