Environment Variable Validation

A schema validation library like valibot checks that every environment variable the app needs is set.

Since Nuxt reads environment variables at build time from the local .env file, you can validate them in a prepare script. This ensures your build fails early if required configuration is missing, preventing deployment of misconfigured applications in CI/CD pipelines.

server.prepare.ts

import { defineNuxtPrepareHandler } from 'nuxt-prepare/config'
import * as v from 'valibot'

export default defineNuxtPrepareHandler(() => {
  const schema = v.object({
    NUXT_PUBLIC_FOO: v.pipe(v.string(), v.nonEmpty()),
  })

  const result = v.safeParse(schema, process.env)

  if (!result.success) {
    console.error(
      `Missing environment variables:\n${result.issues
        .filter(issue => issue.path != null)
        .map(issue => `  - ${issue.path![0].key}: ${issue.message}`)
        .join('\n')}`,
    )
  }

  return {
    ok: result.success,
  }
})