Environment Variable Validation

Using a schema validation library like valibot lets us validate if all environment variables required for the application are set correctly.

Since Nuxt reads the environment variables at build time from the local .env file, you can validate them in a prepare script:

// `server.prepare.ts`
import * as v from 'valibot'
import { defineNuxtPrepareHandler } from 'nuxt-prepare/config'

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,
  }
})