app/services/asserts/MaxAssert.ts

import type { AssertRule } from '~/types/interfaces'

export class MaxAssert implements AssertRule {
  supports(key: string): boolean {
    return key === 'max'
  }

  createRule(criteria: number): (value: unknown) => true | string {
    return (value: unknown) =>
      value === null ||
      value.length <= criteria ||
      `Maximum ${criteria} caractères`
  }
}