@zap-studio/validation — Standard Schema Validation

Setup

import { standardValidate } from '@zap-studio/validation';
import { ValidationError } from '@zap-studio/validation/errors';
import { z } from 'zod';

const UserSchema = z.object({ id: z.string(), email: z.string().email() });

try {
  const user = await standardValidate(UserSchema, { id: '1', email: 'a@b.com' }, {
    throwOnError: true,
  });
  console.log(user.id);
} catch (error) {
  if (error instanceof ValidationError) {
    console.error(error.issues);
  }
}

Core Patterns

Use non-throw mode for explicit branching

import { standardValidate } from '@zap-studio/validation';

const result = await standardValidate(UserSchema, payload);
if (result.issues) {
  return { ok: false, issues: result.issues };
}

return { ok: true, value: result.value };

Build reusable validators

import { createStandardValidator } from '@zap-studio/validation';

const validateUser = createStandardValidator(UserSchema);
const output = await validateUser(payload, { throwOnError: true });

Guard unknown schema-like values

import { isStandardSchema, standardValidate } from '@zap-studio/validation';

async function validateMaybeSchema(schemaLike: unknown, input: unknown) {
  if (!isStandardSchema(schemaLike)) {
    throw new Error('Unsupported schema');
  }
  return standardValidate(schemaLike, input);
}

Common Mistakes

HIGH Calling sync helper on async schema

Wrong:

const value = standardValidateSync(asyncSchema, payload, { throwOnError: true });

Correct:

const value = await standardValidate(asyncSchema, payload, {
  throwOnError: true,
});

standardValidateSync throws when schema validation returns a Promise.

Source: zap-studio/monorepo:packages/validation/src/index.ts

HIGH Treating non-throw result as parsed value

Wrong:

const user = await standardValidate(UserSchema, payload);
console.log(user.id);

Correct:

const result = await standardValidate(UserSchema, payload);
if (result.issues) throw new Error('invalid payload');
console.log(result.value.id);

Default mode returns { value?, issues? }, not direct parsed output.

Source: zap-studio/monorepo:packages/validation/src/index.ts

MEDIUM Skipping runtime schema guard for unknown inputs

Wrong:

await standardValidate(schemaLike as any, payload);

Correct:

if (!isStandardSchema(schemaLike)) throw new Error('Unsupported schema');
await standardValidate(schemaLike, payload);

Validation helpers expect Standard Schema-compatible values and rely on ~standard.validate at runtime.

Source: zap-studio/monorepo:packages/validation/src/index.ts