Zero-dependency module that loads environment variables from a .env.json file into process.env.

reader.env.json.ts

import { readFileSync } from 'fs';
import path from 'path';

type Config = {
  envPath: string;
  encoding: BufferEncoding;
  debug: boolean;
};

export default ({ envPath = path.resolve(process.cwd(), '.env.json'), encoding = 'utf8', debug = false }: Config) => {
  // load json
  let envVars: any = {};
  try {
    const loadFile = readFileSync(envPath, { encoding });
    envVars = JSON.parse(loadFile);
  } catch (error) {
    throw error;
  }

  Object.keys(envVars).forEach((env) => {
    if (!Object.prototype.hasOwnProperty.call(process.env, env)) {
      process.env[env] = envVars[env];
    } else if (debug) {
      // tslint:disable-next-line: no-console
      console.log(`"${env}" is already defined in \`process.env\` and will not be overwritten`);
    }
  });

  return { envVars };
};