Stop Writing Database Configs From Scratch: envconfig-kit v0.2.0

#webdev #javascript #typescript #node

I wrote about making your app crash at startup instead of in production. That post was about envconfig-kit v0.1.0.

Here's what's new in envconfig-kit v0.2.0.

What's New

Framework Presets

Pre-configured schemas for common patterns. Stop writing the same database, Redis, and auth configs over and over:

import { env, presets } from 'envconfig-kit'

const config = env({
  ...presets.server(),      // PORT, HOST, NODE_ENV
  ...presets.database(),   // DATABASE_URL, DATABASE_HOST, etc.
  ...presets.redis(),      // REDIS_URL, REDIS_HOST, etc.
  ...presets.auth(),       // AUTH_JWT_SECRET, etc.
  ...presets.aws(),        // AWS_ACCESS_KEY_ID, etc.
  ...presets.smtp(),       // SMTP_HOST, SMTP_PORT, etc.
  ...presets.cors(),       // CORS_ORIGINS, CORS_METHODS, etc.
})

Custom prefixes work too:

...presets.database('DB_')  // DB_URL, DB_HOST, etc.
...presets.redis('CACHE_')  // CACHE_URL, CACHE_HOST, etc.

New Validators

Enum Type - Type-safe environment values:

const config = env({
  NODE_ENV: { 
    type: 'enum', 
    values: ['development', 'staging', 'production'] as const,
    default: 'development'
  },
})
// config.NODE_ENV is typed as 'development' | 'staging' | 'production'

Array Type - Parse comma-separated values:

const config = env({
  ALLOWED_HOSTS: { type: 'array' },  // "a,b,c" → ["a", "b", "c"]
  TAGS: { type: 'array', separator: '|' },  // custom separator
})

JSON Type - Parse JSON strings:

const config = env({
  FEATURE_FLAGS: { type: 'json' },
})
// FEATURE_FLAGS='{"darkMode":true}' → { darkMode: true }

Regex Type - Custom pattern validation:

const config = env({
  API_VERSION: { 
    type: 'regex', 
    pattern: /^v\d+\.\d+$/ 
  },
})
// Only accepts "v1.0", "v2.1", etc.

Integer Type - Whole numbers only:

const config = env({
  PORT: { type: 'integer' },  // Stricter than 'number'
})

Secret Masking

Mark secrets and they'll be masked automatically in error messages:

const config = env({
  API_KEY: { type: 'string', secret: true },
  DATABASE_PASSWORD: { type: 'string', secret: true },
})

When validation fails, error messages show API_KEY=**** instead of the actual value. No more accidentally logging secrets.

Custom Validation

Add your own validation logic:

const config = env({
  PORT: { 
    type: 'number',
    validate: (value) => value >= 1024 && value <= 65535
  },
  MAX_CONNECTIONS: {
    type: 'integer',
    validate: (value) => value > 0 && value <= 1000,
    default: 100
  },
})

Real-World Example

Here's how you'd configure a typical API with v0.2.0:

import { env, presets } from 'envconfig-kit'

export const config = env({
  // Server (preset)
  ...presets.server(),

  // Database (preset)
  ...presets.database(),

  // Redis (preset)
  ...presets.redis(),

  // Auth (preset)
  ...presets.auth(),

  // External services
  STRIPE_KEY: { type: 'string', secret: true },
  SENDGRID_KEY: { type: 'string', secret: true },

  // CORS (preset)
  ...presets.cors(),

  // Feature flags with enum
  FEATURE_MODE: {
    type: 'enum',
    values: ['basic', 'premium', 'enterprise'] as const,
    default: 'basic'
  },

  // Custom validation
  MAX_CONNECTIONS: {
    type: 'integer',
    validate: (value) => value > 0 && value <= 1000,
    default: 100
  },
})