utility.js

const CSS_CLASS_SEPARATOR = " ";

/**
 * Creates className from attributes joined with class separator.
 * @param classes Array
 * @param separator string
 * @return string
 */
export function createClassName(...classes) {
  return classes.filter((item) => item).join(CSS_CLASS_SEPARATOR);
}

export function clamp(number, lowerBound, upperBound) {
  number = Math.min(number, upperBound);
  number = Math.max(number, lowerBound);
  return number;
}

export function omit(object, key) {
  const result = Object.assign({}, object);
  if (Array.isArray(key)) {
    key.forEach((item) => {
      delete result[item];
    });
  } else {
    delete result[key];
  }
  return result;
}

export const without = (array, index) =>
  index < 0 ? array : [...array.slice(0, index), ...array.slice(index + 1)];

// get the last 6 digits of this base 36 number (fraction)
export const generateRandomKey = () => Math.random().toString(36).slice(-6);

export const generateRandomKeys = (count, exceptions = []) => {
  const keys = [];
  while (count) {
    const randomKey = generateRandomKey();
    if (exceptions.includes(randomKey)) {
      continue;
    }
    keys.push(randomKey);
    --count;
  }
  if (keys.length === 1) {
    return keys[0];
  }
  return keys;
};

export const todoOccurrenceCount = (lists, todoId) =>
  Object.keys(lists)
    .map((key) => lists[key].todoIds.includes(todoId))
    .reduce((sum, value) => sum + value, 0);