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Scalar Validator

The Scalar Validator validates scalar values (strings, numbers, booleans, etc.) with flexible validation rules. It's ideal for form fields, API parameters, and configuration values.

Basic Usage​

import { v, validate } from "@warlock.js/seal";

enum Status {
  Active = "active",
  Inactive = "inactive",
  Pending = "pending"
}

const schema = v.scalar()
  .required()
  .enum(Status);

const result = await validate(schema, "active");
// Result: { isValid: true, data: "active" }

What's Included​

Validators (24 methods)​

  • Value Selection: enum(), in(), oneOf(), allowsOnly(), forbids(), notIn()
  • Accepted/Declined: accepted(), declined(), plus conditional variants
  • Conditional Accepted: acceptedIf(), acceptedUnless(), acceptedIfRequired(), acceptedIfPresent(), acceptedWithout()
  • Conditional Declined: declinedIf(), declinedUnless(), declinedIfRequired(), declinedIfPresent(), declinedWithout()

View all validators →

Common Patterns​

Enum Validation​

enum Status {
  Active = "active",
  Inactive = "inactive",
  Pending = "pending"
}

const statusSchema = v.scalar()
  .required()
  .enum(Status);

const result = await validate(statusSchema, "active");
// Result: { isValid: true, data: "active" }

Value Selection​

const roleSchema = v.scalar()
  .required()
  .in(["admin", "user", "guest"]);

const result = await validate(roleSchema, "admin");
// Result: { isValid: true, data: "admin" }

Accepted/Declined Values​

// Accepted: 1, "1", true, "true", "yes", "y", "on"
const termsSchema = v.scalar()
  .required()
  .accepted();

// Declined: 0, "0", false, "false", "no", "n", "off"
const spamSchema = v.scalar()
  .required()
  .declined();

Conditional Acceptance​

const newsletterSchema = v.scalar()
  .acceptedIf("subscribe", true);

// Valid if subscribe === true
const result = await validate(newsletterSchema, "yes", {
  subscribe: true
});

Inherited Methods​

The Scalar Validator extends BaseValidator and inherits all base validation methods:

  • Basic Rules: required(), optional(), present(), nullable()
  • Comparison: equal(), notEqual(), sameAs(), differentFrom()
  • Type Checking: typeOf(), instanceOf()
  • Advanced: when(), custom(), transform()

View Base Validator →

See Also​