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Extending Validators

Create custom validators by extending base classes.

Basic Extension​

Extending BaseValidator​

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

class CustomValidator extends BaseValidator {
  constructor() {
    super();
    this.addRule(customRule);
  }
  
  customMethod() {
    // Custom validation logic
    return this;
  }
}

Using Custom Validator​

const customValidator = new CustomValidator();
const result = await customValidator.validate(data, context);

Advanced Extension​

Custom Validator with Methods​

class EmailValidator extends BaseValidator {
  constructor() {
    super();
    this.addRule(emailRule);
  }
  
  domain(domain: string) {
    this.addRule(domainRule, { domain });
    return this;
  }
  
  notDisposable() {
    this.addRule(notDisposableRule);
    return this;
  }
}

// Usage
const emailSchema = new EmailValidator()
  .domain("example.com")
  .notDisposable();

Custom Validator with Mutators​

class StringValidator extends BaseValidator {
  constructor() {
    super();
    this.addRule(stringRule);
  }
  
  trim() {
    this.addMutator(trimMutator);
    return this;
  }
  
  lowercase() {
    this.addMutator(lowercaseMutator);
    return this;
  }
}

// Usage
const stringSchema = new StringValidator()
  .trim()
  .lowercase();

Real-World Examples​

Custom Validator​

class UsernameValidator extends BaseValidator {
  constructor() {
    super();
    this.addRule(requiredRule);
    this.addRule(minLengthRule, { minLength: 3 });
    this.addRule(maxLengthRule, { maxLength: 20 });
    this.addRule(alphanumericRule);
  }
  
  notReserved() {
    this.addRule(notReservedRule);
    return this;
  }
  
  async notExists() {
    this.addRule(notExistsRule);
    return this;
  }
}

// Usage
const usernameSchema = new UsernameValidator()
  .notReserved()
  .notExists();

Custom Mutator Validator​

class TextValidator extends BaseValidator {
  constructor() {
    super();
    this.addRule(stringRule);
  }
  
  trim() {
    this.addMutator(trimMutator);
    return this;
  }
  
  titleCase() {
    this.addMutator(titleCaseMutator);
    return this;
  }
  
  maxLength(length: number) {
    this.addRule(maxLengthRule, { maxLength: length });
    return this;
  }
}

// Usage
const textSchema = new TextValidator()
  .trim()
  .titleCase()
  .maxLength(100);

See Also​