Stringcaster for Typescript

Implementation of stringcaster package for use with Typescript classes and decorators.

See stringcaster docs for cast options. This package includes all the functionality of stringcaster and adds the envVar property decorator on top of it.

Getting Started

Let's say you have .env files like this:

# /.env

MINIFY=true
DEFAULT_LOCALE=en-GB
SUPPORTED_LOCALES=en-GB,en-US,es,jp
PORT=3000
INFO_OBJECT=date: 2017, author: John Doe

And you need to create a config object using this data. Now using the envVar decorator you can do the following:

// /config.ts

import {
  envVar,
  toBoolean,
  toString,
  toNumber,
  toArray,
  toObject
} from "typescript-stringcaster";
import * as dotenv from "dotenv";
dotenv.config();

const source = process.env; // you actually have to pass this

class Config {
  @envVar({ cast: toBoolean, defaultValue: false, source })
  MINIFY: boolean;

  @envVar({ cast: toString, defaultValue: "en-US", source })
  DEFAULT_LOCALE: string;

  @envVar({ cast: toArray, source })
  SUPPORTED_LOCALES: [string];

  @envVar({ cast: toNumber, source })
  PORT: number;

  @envVar({ cast: toObject, source, sourceKey: "INFO_OBJECT" })
  INFO: object;
}

export default new Config();

Docs

@envVar decorator

Parameters:

• source (required) - A object containing the values source (e. g. process.env)
• defaultValue optional - default value that will be provided if source does not contain the value for this key
• sourceKey optional - Use if the key in source object is different from the property name
• cast optional - A convert function, will be called on the property value. Can be either a cast function from stringcaster or custom function.