parse

Validates data and returns it if valid, or throws ValidationError. Handy on the server, where an invalid request should stop processing right away.

Signature

function parse<S extends Schema>(schema: S, value: unknown, options?: Options): Infer<S>

Parameters

Parameter	Type	Description
schema	Schema	The schema to validate against
value	unknown	Any data
options	Options	{ all?: boolean } — as in validate

Returns

Cleaned, typed data — the same as result.data of validate.

Throws

• ValidationError — if the data is invalid. It contains errors and issues.
• Error — if the schema contains checkAsync. Use parseAsync.

Examples

Express

import { parse, ValidationError } from 'tinyval';

app.post('/users', (req, res) => {
  try {
    const user = parse(CreateUser, req.body);
    // user is validated and typed
  } catch (e) {
    if (e instanceof ValidationError) return res.status(422).json({ errors: e.errors });
    throw e;
  }
});

Environment variables

const env = parse(
  object({
    PORT: optional(coerce.number(), 3000),
    DATABASE_URL: string(),
    DEBUG: optional(coerce.boolean(), false),
  }),
  process.env,
);
// without DATABASE_URL the app fails on startup with a clear error

See also

• ValidationError
• parseAsync
• validate — without exceptions