# new AsyncValidator()

Abstract class for defining asynchronous validators.

See:

• Validator For the base synchronous validator.

View Source validation/Validators/AsyncValidator.ts, line 57

Example

```typescript
// Example of an asynchronous validator that compares value against a timeout
class TimeoutValidator extends AsyncValidator<{ timeout?: number }> {
  constructor(message: string = "Validation failed due to timeout") {
    super(message);
  }

  async hasErrors(value: number, options?: { timeout?: number }) {
    const delay = options?.timeout ?? 100;

    // async call
    await new Promise(res => setTimeout(res, delay));

    if (value > delay) {
      // Rejects the validation after waiting the delay if value is greater
      return Promise.resolve(this.getMessage());
    }

    // Passes the validation after waiting the delay
    return Promise.resolve(undefined);
  }
}

// Example usage:
const validator = new TimeoutValidator();

async function runValidation() {
 const error = await validator.hasErrors(50, { timeout: 100 });
 if (error) {
   return console.error('Validation error:', error);
 }
 console.log('Value is valid');
}

await runValidation();
```

- If `value > timeout`, the validator waits for the delay and then rejects with an error.
- If `value <= timeout`, the validator waits for the delay and resolves successfully with `undefined`.