valext

Minimal helper for extracting typed, validated values from Valibot schemas.

valibot.safeParse() works — but it’s not very intuitive.
It leads to very procedural code, where you manually handle control flow and flatten errors — a common task when logging structural data for observability. It reads like plumbing — not like intent.

...
import { safeParse, flatten } from 'valibot'

const result = safeParse(schema, input)

if (!result.success) {
  const issues = flatten(result.issues).nested
  logger.warn('validation failed', { issues })
}

This boilerplate is everywhere, and it hides your intent behind ceremony.

valext introduces a small shift:

✨ Extract values fluently — and express what you mean.

...
import { extract } from '@gambonny/valext'

const result = extract(schema).from(input, issues => {
  logger.warn('validation failed', { issues })
})

• ✅ Fluent API that reads like intent — extract(...).from(...)
• ✅ Ergonomic structure for validation — no verbose branching or manual flattening
• ✅ Structured error handling — pass a callback to receive flattened issues

---

Installation

  pnpm add @gambonny/valext

---

Example in Hono

import { validator } from 'hono/validator'
import { extract } from '@gambonny/valext'
import { credentials } from './schemas'

app.post(
  '/signup',
  validator('json', async (body, c) => {
    const { success, output } = extract(credentials).from(body, issues =>
      c.var.logger.warn('validation failed', { issues }),
    )

    return success ? output : c.text('Invalid input')
  }),
)

---

API

extract(schema).from(input, onError?)

Returns:

{
  success: true;
  output: T;
  issues: undefined;
}

or:

{
  success: false;
  output: undefined;
  issues: ValibotFlattenedIssues;
}

---

extract(schema).safe(input, onError?)

Exactly like valibot.safeParse(), but lets you pass a callback for flattened errors.

---

extract(schema).parse(input)

Exactly like valibot.parse(). Will throw if input is invalid.

---

Design Notes

• ✅ valext uses valibot.safeParse() under the hood.
• ✅ Errors are flattened with valibot.flatten().nested for easy rendering/logging.
• ✅ If you need raw nested issues, just use valibot.safeParse() directly — you’re not locked in.

Reminder: valext is not an abstraction layer — it’s a tool for making your intent clear at the point of use.

License

MIT