How to use lazy-universal-dotenv - 3 common examples

export function loadEnv(options = {}) {
  const defaultNodeEnv = options.production ? 'production' : 'development';
  const env = {
    NODE_ENV: JSON.stringify(process.env.NODE_ENV || defaultNodeEnv),
    // This is to support CRA's public folder feature.
    // In production we set this to dot(.) to allow the browser to access these assests
    // even when deployed inside a subpath. (like in GitHub pages)
    // In development this is just empty as we always serves from the root.
    PUBLIC_URL: JSON.stringify(options.production ? '.' : ''),
  };

  const { stringified } = getEnvironment();

  Object.keys(process.env)
    .filter(name => /^STORYBOOK_/.test(name))
    .forEach(name => {
      env[name] = JSON.stringify(process.env[name]);
    });

  return {
    'process.env': Object.assign({}, env, stringified),
  };
}

// In development this is just empty as we always serves from the root.
    PUBLIC_URL: options.production ? '.' : '',
  };

  Object.keys(process.env)
    .filter(name => /^STORYBOOK_/.test(name))
    .forEach(name => {
      env[name] = process.env[name];
    });

  const base = Object.entries(env).reduce(
    (acc, [k, v]) => Object.assign(acc, { [k]: JSON.stringify(v) }),
    {}
  );

  const { stringified, raw } = getEnvironment({ nodeEnv: env.NODE_ENV });

  const fullRaw = { ...env, ...raw };

  fullRaw.NODE_PATH = nodePathsToArray(fullRaw.NODE_PATH || '');

  return {
    stringified: { ...base, ...stringified },
    raw: fullRaw,
  };
}

PUBLIC_URL: options.production ? '.' : '',
    PREVIEW_URL: process.env.PREVIEW_URL || '',
  };

  Object.keys(process.env)
    .filter(name => /^STORYBOOK_/.test(name))
    .forEach(name => {
      env[name] = process.env[name];
    });

  const base = Object.entries(env).reduce(
    (acc, [k, v]) => Object.assign(acc, { [k]: JSON.stringify(v) }),
    {}
  );

  const { stringified, raw } = getEnvironment({ nodeEnv: env.NODE_ENV });

  const fullRaw = Object.assign({}, env, raw);

  fullRaw.NODE_PATH = nodePathsToArray(fullRaw.NODE_PATH || '');

  return {
    stringified: Object.assign({}, base, stringified),
    raw: fullRaw,
  };
}