@philiprehberger/config-layer
v0.1.7348 downloadsMIT
Layered configuration loader with typed output and multiple sources
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npm install @philiprehberger/config-layerREADME
@philiprehberger/config-layer
Layered configuration loader with typed output and multiple sources
Installation
npm install @philiprehberger/config-layer
Usage
import { loadConfig, envSource, objectSource } from '@philiprehberger/config-layer';
const config = loadConfig({
port: { type: 'number', default: 3000 },
dbUrl: { type: 'string', required: true, env: 'DATABASE_URL' },
debug: { type: 'boolean', default: false },
}, [
envSource(),
objectSource({ port: 8080 }),
]);
// config.port → 8080 (from objectSource, overrides default)
// config.dbUrl → from DATABASE_URL env var
// config.debug → false (default)
Sources
Sources are applied in order — later sources override earlier ones:
const config = loadConfig(schema, [
envSource(), // Load from process.env
envSource('APP_'), // Load from env vars with APP_ prefix
objectSource({ port: 9090 }), // Override with explicit values
]);
Schema
const schema = {
// Shorthand
host: 'string',
port: 'number',
debug: 'boolean',
// Full definition
dbUrl: {
type: 'string',
required: true, // Throws if missing (default: true)
env: 'DATABASE_URL', // Map to specific env var name
default: undefined, // Default value if not provided
},
};
API
| Export | Description |
|---|---|
loadConfig(schema, sources) | Load and validate config from sources |
envSource(prefix?) | Read from process.env, optionally filtering by prefix |
objectSource(obj) | Read from a plain object |
ConfigFieldDef
| Property | Type | Default | Description |
|---|---|---|---|
type | 'string' | 'number' | 'boolean' | — | Value type (auto-coerced) |
required | boolean | true | Throw if missing |
default | string | number | boolean | — | Default value |
env | string | — | Override env var name |
Development
npm install
npm run build
npm test
Support
If you find this project useful: