@sendbird/uikit-utils/src/shared/rtl.ts

A collection of utility functions and constants for building chat UI components with Sendbird UIKit.

const isRTLString = (dir: 'start' | 'end', str?: string) => {
  if (!str || str.length === 0) {
    return false;
  }

  const trimmedStr = str.trimStart();
  if (trimmedStr.length === 0) {
    return false;
  }

  const char = dir === 'start' ? Array.from(trimmedStr)[0] : Array.from(trimmedStr).pop();
  const point = char?.codePointAt(0);
  if (point === undefined) {
    return false;
  }

  return isRTLCodePoint(point);
};

export const isStartsWithRTL = (str?: string): boolean => {
  return isRTLString('start', str);
};

export const isEndsWithRTL = (str?: string): boolean => {
  return isRTLString('end', str);
};

const isRTLCodePoint = (codePoint: number) => {
  for (const [start, end] of rtlCodePointRanges) {
    if (codePoint >= start && codePoint <= end) {
      return true;
    }
  }
  return false;
};

const rtlCodePointRanges = [
  [0x0590, 0x05ff], // Hebrew
  [0x0600, 0x06ff], // Arabic
  [0x0750, 0x077f], // Arabic Supplement
  [0x08a0, 0x08ff], // Hebrew Supplement
  [0xfb1d, 0xfb4f], // Hebrew Presentation Forms
  [0xfe70, 0xfeff], // Arabic Presentation Forms-B
  [0x1ee00, 0x1eeff], // Arabic Mathematical Alphabetic Symbols
];