Typescript version of Strapi's env mini-library

env.ts

'use strict';
import { EnvVars } from './types';

// Taken from https://github.com/strapi/strapi/blob/c90e3eb67bf2c235c2fdd1b5607eda6b649d9f10/packages/strapi/lib/core/app-configuration/env-helper.js

const _ = require('lodash');

type Translator<T = any> = (key: keyof EnvVars, defaultValue?: T) => T

const defaultEnv: Translator = (key, defaultValue) => {
  return _.has(process.env, key) ? process.env[key] : defaultValue;
}

const int: Translator<number> = function (key, defaultValue) {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  const value = process.env[key];
  return parseInt(value as any, 10);
}

const float: Translator<number> = (key, defaultValue) => {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  const value = process.env[key];
  return parseFloat(value as any);
}

const bool: Translator<boolean> = (key, defaultValue) => {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  const value = process.env[key];
  return value === 'true';
}

const json: Translator<{}> = (key, defaultValue) => {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  const value = process.env[key];
  try {
    return JSON.parse(value as any);
  } catch (error) {
    throw new Error(`Invalid json environment variable ${key}: ${error.message}`);
  }
}

const array: Translator<Array<any>> = (key, defaultValue) => {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  let value = process.env[key].toString();

  if (value.startsWith('[') && value.endsWith(']')) {
    value = value.substring(1, value.length - 1);
  }

  return value.split(',').map(v => {
    return _.trim(_.trim(v, ' '), '"');
  });
}

const date: Translator<Date> = (key, defaultValue) => {
  if (!_.has(process.env, key)) {
    return defaultValue;
  }

  const value = process.env[key];
  return new Date(value);
}

const env = Object.assign(
  defaultEnv,
  {
    int,
    float,
    bool,
    date,
    json,
    array
  }
)

export default env