gab-social/app/javascript/gabsocial/utils/cursor_token_match.js

'use strict';

export function textAtCursorMatchesToken(str, caretPosition, searchTokens) {
  let word;

  let left = str.slice(0, caretPosition).search(/\S+$/);
  let right = str.slice(caretPosition).search(/\s/);

  if (right < 0) {
    word = str.slice(left);
  } else {
    word = str.slice(left, right + caretPosition);
  }

  if (!word || word.trim().length < 2 || searchTokens.indexOf(word[0]) === -1) {
    return [null, null];
  }

  word = word.trim().toLowerCase();

  if (word.length > 0) {
    return [left + 1, word];
  }

  return [null, null];
};