utils.ts

const isLetter = (char: string) => {
  return /^\p{L}/u.test(char);
};

const isUpperCase = (char: string) => {
  return char === char.toUpperCase();
};

export const isAt = (value: string): boolean => {
  // Check if the first character is '@'
  const first = value.charAt(0);
  return first === "@";
};

export const getCapitalPercentage = (str: string): number => {
  let totalLetters = 0;
  let upperLetters = 0;

  for (const currentLetter of str) {
    if (!isLetter(currentLetter)) continue;

    if (isUpperCase(currentLetter)) {
      upperLetters++;
    }

    totalLetters++;
  }

  return upperLetters / totalLetters;
};

export const isUri = (value: string): boolean => {
  if (!value) return false;

  // Check for illegal characters
  if (/[^a-z0-9\:\/\?\#\[\]\@\!\$\&\'\(\)\*\+\,\;\=\.\-\_\~\%]/i.test(value)) {
    return false;
  }

  // Check for hex escapes that aren't complete
  if (/%[^0-9a-f]/i.test(value) || /%[0-9a-f](:?[^0-9a-f]|$)/i.test(value)) {
    return false;
  }

  // Directly from RFC 3986
  const split = value.match(
    /(?:([^:\/?#]+):)?(?:\/\/([^\/?#]*))?([^?#]*)(?:\?([^#]*))?(?:#(.*))?/,
  );

  if (!split) return false;

  const [, scheme, authority, path] = split;

  // Scheme and path are required, though the path can be empty
  if (!(scheme && scheme.length && path.length >= 0)) return false;

  // If authority is present, the path must be empty or begin with a /
  if (authority && authority.length) {
    if (!(path.length === 0 || /^\//.test(path))) return false;
  } else if (/^\/\//.test(path)) {
    // If authority is not present, the path must not start with //
    return false;
  }

  // Scheme must begin with a letter, then consist of letters, digits, +, ., or -
  if (!/^[a-z][a-z0-9\+\-\.]*$/.test(scheme.toLowerCase())) return false;

  return true;
};

export const isBreak = (word: string): boolean => {
  return word.trim() === "";
};