release notes

An extensible wrapper of the popular config package, supporting placeholder resolution (or variable expansion), encrypted and default (fallback) values.

To use the module, simply import the substituted package as you would with the popular config package

const config = require('@alt-javascript/config');

config.get('key');
config.get('nested.key');
config.get('unknown','use this instead'); // this does not throw an error

Config values that include the common ${placeholder} syntax, will resolve the inline placeholders, so the config.get('placeholder')' path below will return start.one.two.end.

Config values that start with the prefix enc. will be decrypted with the jasypt package port, with the passphrase being sourced from the process.env.NODE_CONFIG_PASSPHRASE environment variable.

local-development.json

{
  "key": "value",
  "one" : "one",
  "placeholder": "start.${one}.${nested.two}.end",
  "placeholderEncrypted": "start.${nested.encrypted}.end",
  "nested" : {
    "key" : "value",
    "two" : "two",
    "placeholder": "start.${one}.${nested.two}.end",
    "encrypted" : "enc.pxQ6z9s/LRpGB+4ddJ8bsq8RqELmhVU2",
    "encryptedWithSecret" : "enc./emLGkD3cbfqoSPijGZ0jh1p1SYIHQeJ"
  }
}

Testing config is hard, and testability is a first class concern at @alt-javascript so the config wrapper, and the module exports an EphemeralConfig that can source config paths from a plain old javascript object as follows, allowing you to assert varying configurations easily

const {
    EphemeralConfig, ValueResolvingConfig, PlaceHolderResolver, PlaceHolderSelector
    
} = require('@alt-javascript/config');

const ephemeralConfig = new EphemeralConfig({
    key: 'value',
    nested: {
        key: 'value',
    },
});

const placeHolderResolver = new PlaceHolderResolver(new PlaceHolderSelector());
const config = new ValueResolvingConfig(ephemeralConfig,placeHolderResolver );

May be freely distributed under the MIT license.

Copyright (c) 2021 Craig Parravicini