Some JS and TS code snippets that I need to use sometimes

utils.ts

// Generate random string
export const generateUID = (length: number) =>
  Array(length)
    .fill("")
    .map((v) => Math.random().toString(36).charAt(2))
    .join("");

// Convert ArrayBuffer to HEX string
export const bytesToHEX = (bytes: ArrayBuffer) =>
  Array.from(new Uint8Array(bytes)).map(b => b.toString(16).padStart(2, '0')).join('');

// Date string in RU format with timezone
export const date = new Date()
        .toLocaleString("ru-RU", { timeZone: "Europe/Moscow" })
        .replaceAll("/", ".")
        .split(",")[0];

/**
 * Checks if string is an isogram (if it has only unique chars) 
 * @param str string to check
 * @returns boolean true if the string is isogram, false otherwise
 */
export function isIsogram(str: string): boolean {
  return !/(\w).*\1/.test(str);
}

/**
 * Group array of objects by given keys
 * @param keys keys to be grouped by
 * @param array objects to be grouped
 * @returns an object with objects in `array` grouped by `keys`
 * @see <https://gist.github.com/mikaello/06a76bca33e5d79cdd80c162d7774e9c>
 */
export const groupBy = <T>(keys: (keyof T)[]) => (array: T[]): Record<string, T[]> =>
  array.reduce((objectsByKeyValue, obj) => {
    const value = keys.map((key) => obj[key]).join('-');
    objectsByKeyValue[value] = (objectsByKeyValue[value] || []).concat(obj);
    return objectsByKeyValue;
  }, {} as Record<string, T[]>);

/**
 * Generates SHA-256 string for provided string
 * @param str payload data
 * @returns hash string in promise
 */
export async function SHA256(str: string): Promise<string> {
  const encoder = new TextEncoder();
  const blockDataBuffer = encoder.encode(str);
  const hashBuffer = await crypto.subtle.digest("SHA-256", blockDataBuffer);
  const hashString = Array.from(new Uint8Array(hashBuffer)).map((b) =>
    b.toString(16).padStart(2, "0");
  ).join("");
  return hashString;
}