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String Validator

The String Validator provides comprehensive string validation and transformation capabilities. It includes all methods from BaseValidator and ScalarValidator, plus string-specific validation rules and built-in mutators.

Quick Example​

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

const schema = v.object({
  email: v.string().required().email().lowercase(),
  username: v.string().required().lengthBetween(3, 20).alphanumeric(),
  bio: v.string().maxLength(500).trim()
});

Overview​

This validator provides 68 methods organized into:

🔧 Mutators (33 methods)​

Transform string values before validation:

  • Case Conversion: lowercase(), uppercase(), camelCase(), snakeCase(), kebabCase(), slug(), etc.
  • Trimming & Padding: trim(), ltrim(), rtrim(), padStart(), padEnd(), etc.
  • Encoding & Decoding: base64Encode(), urlEncode(), htmlEscape(), etc.
  • String Manipulation: replace(), replaceAll(), append(), prepend(), truncate(), mask(), etc.
  • Advanced: toAlpha(), toAlphanumeric(), removeNumbers(), safeHtml(), etc.

👉 View All Mutators →

✅ Validators (35 methods)​

Validate string format and content:

  • Format Validation: email(), url(), ip(), ip4(), ip6(), creditCard()
  • Length Validation: minLength(), maxLength(), length(), between(), minWords(), maxWords(), words()
  • Content Validation: contains(), startsWith(), endsWith(), pattern(), alpha(), alphanumeric(), numeric()
  • Color Validation: color(), hexColor(), rgbColor(), rgbaColor(), hslColor(), lightColor(), darkColor()
  • Password Validation: strongPassword()
  • Value Selection: enum(), oneOf(), in(), allowsOnly(), forbids(), notIn()

👉 View All Validators →

Common Patterns​

Email Validation​

v.string().required().lowercase().trim().email()

email Schema​

const emailSchema = v.string()
  .required()
  .lowercase()
  .trim()
  .email();

const result = await validate(emailSchema, "  USER@EXAMPLE.COM  ");
// Result: { isValid: true, data: "user@example.com" }

Username Validation​

v.string().required().lengthBetween(3, 20).alphanumeric()

URL Slug Generation​

const slugSchema = v.string()
  .required()
  .trim()
  .lowercase()
  .slug();

const result = await validate(slugSchema, "  My Blog Post Title  ");
// Result: { isValid: true, data: "my-blog-post-title" }

Password with Multiple Rules​

const passwordSchema = v.string()
  .required()
  .minLength(8)
  .strongPassword();

const result = await validate(passwordSchema, "MyStr0ng!Pass");
// Result: { isValid: true, data: "MyStr0ng!Pass" }

Inherited Methods​

The String Validator inherits all methods from BaseValidator and ScalarValidator, including:

From BaseValidator​

  • Core validation: required(), present(), optional(), forbidden()
  • Field comparison: equal(), sameAs(), differentFrom()
  • Conditional validation: when(), requiredIf(), presentIf(), etc.
  • Advanced methods: refine(), default(), label(), toJSON(), outputAs(), etc.

From ScalarValidator​

  • Value selection: enum(), oneOf(), in(), allowsOnly(), forbids(), notIn()

See Also​