Loaders

Discover all the ways you can load from a configuration source.

.addFromEnvironment(prefix?)

This loader takes from process.env and parses all keys into a complex object.

Optionally, a prefix argument can be given to filter out keys that aren't relevant. For example, when you give it a prefix of NEATCONFIG_ then it will ignore keys like TERM=xterm-256color. And it will detect keys like NEATCONFIG_HELLO=world and strip the prefix before parsing. So that the key will become { hello: "world" }.

import { createConfigLoader } from 'neat-config';

export const config = createConfigLoader()
  .addFromEnvironment()
  .load();

HELLO_WORLD=foo
FOO__BAR__BAZ=hello

{
  helloWorld: "foo",
  foo: {
    bar: {
      baz: "hello"
    }
  }
}

.addFromFile(path, options?)

interface Options {
  prefix?: string;
  type?: ParserTypes;
}

This loader can load any of the supported file types (.env, .json). It will try to use the file extension to determine how to parse the file, you can manually choose the parser by using the type key in the options. In the options you can also specify a prefix, which works the same as in addFromEnvironment().

Some details on implementation:

• The path is relative to your current working directory.
• The .env file loader supports comments with #.
• The .json file loader does not support prefix stripping.

import { createConfigLoader, ParserTypes } from 'neat-config';

export const config = createConfigLoader()
  .addFromFile(".env", { prefix: "CONF_" })
  .addFromFile("fileName", { type: ParserTypes.JSON })
  .addFromFile("config.json")
  .load();

CONF_HELLO_WORLD_ENV=foo

{
  helloJson: "world"
}

{
  evenMoreJson: "yes"
}

{
  helloWorldEnv: "foo",
  helloJson: "world",
  evenMoreJson: "yes"
}

.addFromDirectory(path, options?)

interface Options {
  prefix?: string
}

This loader loads in data from a directory structure, the filename is used as the key and the contents of the file is the value. In the options you can specify a prefix, which works the same as in addFromEnvironment().

The path is relative to your current working directory.

import { createConfigLoader, ParserTypes } from 'neat-config';

export const config = createConfigLoader()
  .addFromDirectory("./loadme")
  .load();

Hello world!

{
  fooBar: "Hello world!"
}

.addFromCLI(prefix?)

This loader can load in configuration keys from CLI arguments. In prefix parameter works the same as in addFromEnvironment().

The loader supports both --KEY=VALUE and the --KEY VALUE syntax for arguments.

import { createConfigLoader, ParserTypes } from 'neat-config';

export const config = createConfigLoader()
  .addFromCLI()
  .load();

ts-node config.ts --foo-bar hello --baz=world

{
  fooBar: "hello",
  baz: "world"
}