@dumpstate/config

File and env configuration loader.

Install

Install package:

npm install @dumpstate/config --save

Conventions

Module loads the configuration from:

1. default.application.json file under specified directory - ./config/ folder of a current working directory by default,
2. application.json file under specified directory - ./config/ folder of a current working directory by default,
3. *.json file which path is provided as APPLICATION_CONFIG environment variable,
4. environment - all environment variable prefixed with ${APP_NAME}${SEPARATOR} where APP_NAME is your applicaiton prefix, e.g. FOO and SEPARATOR is configured env name separator, __ by default.

All the configuration is validated with ajv. The schema of the config is expected to be defined with JSON TypeDef.

Usage

1. Define your schema with JSON TypeDef.

const ConfigSchema = {
	properties: {
		db: {
			properties: {
				host: { type: "string" },
				port: { type: "int32" },
			},
		},
	},
} as const

2. Load the config.

import { loadConfig } from "@dumpstate/config"

const config = loadConfig(ConfigSchema, { appName: "foo" })

Note the config type is derived from the JSON TypeDef. config object is guaranteed to follow the schema declaration thanks to ajv.

In case you'd like to pass config reference around, declare the config type:

import { ConfigSchemaType } from "@dumpstate/config"

type Config = ConfigSchemaType<typeof ConfigSchema>

API

loadConfig(schema, opts)

where:

• schema - JSON object of JSON TypeDef schema,
• opts - JSON object containing the following parameters:
  • appName - the name of the application - required as prefix for environment loader (the name is being snake and upper cased),
  • separator - separator of environment variable - __ by default,
  • targetDir - target directory of the file loader - ${CWD}/config/ by default,
  • configPath - path to configuration file; could be provided as APPLICATION_CONFIG environment variable instead; null by default.