Migration from dotenv

npm install @ctroenv/core @ctroenv/node

// Before (dotenv)
import "dotenv/config"
 
const dbUrl = process.env.DATABASE_URL
if (!dbUrl) {
  throw new Error("DATABASE_URL is required")
}
const port = Number(process.env.PORT) || 3000
 
// After (CtroEnv)
import { defineEnv, string, number } from "@ctroenv/core"
import { loadEnv } from "@ctroenv/node"
 
const env = defineEnv(
  {
    DATABASE_URL: string().url(),
    PORT: number().port().default(3000),
  },
  { source: loadEnv() },
)

// Before: manual checks everywhere
function getConfig() {
  const nodeEnv = process.env.NODE_ENV
  if (!["dev", "prod"].includes(nodeEnv ?? "")) {
    throw new Error("Invalid NODE_ENV")
  }
  return { nodeEnv }
}
 
// After: single schema definition
const env = defineEnv({
  NODE_ENV: pick(["dev", "prod"]),
})

// Before: process.env.PORT is string | undefined
const port = process.env.PORT  // string | undefined
 
// After: env.PORT is number (or throws at init)
const port = env.PORT  // number

// Before: errors surface when the value is first accessed
function handleRequest() {
  const db = process.env.DATABASE_URL  // May fail deep in request handling
}
 
// After: errors surface at startup
const env = defineEnv({ ... })  // Fails immediately if anything is wrong

// Before: validation scattered across the codebase
// After: all env vars defined and validated in one place