meteor/packages/ejson/utils.js

export const isFunction = (fn) => typeof fn === "function";

export const isObject = (fn) => typeof fn === "object";

export const keysOf = (obj) => Object.keys(obj);

export const lengthOf = (obj) => {
  let count = 0;
  for (const key in obj) {
    if (hasOwn(obj, key)) count++;
  }
  return count;
};

/**
 * Counts own properties of obj, but stops early once count exceeds limit.
 * Useful for hot-path checks like `lengthOfWithLimit(obj, 1) === 1`
 * without iterating all keys of large objects.
 * @param {Object} obj
 * @param {number} limit - stop counting beyond this value
 * @returns {number} exact count if <= limit, otherwise limit + 1
 */
export const lengthOfWithLimit = (obj, limit) => {
  let count = 0;
  for (const key in obj) {
    if (hasOwn(obj, key) && ++count > limit) return count;
  }
  return count;
};

export const hasOwn = (obj, prop) => Object.prototype.hasOwnProperty.call(obj, prop);

export const convertMapToObject = (map) =>
  Array.from(map).reduce((acc, [key, value]) => {
    // reassign to not create new object
    acc[key] = value;
    return acc;
  }, {});

export const isArguments = (obj) => obj != null && hasOwn(obj, "callee");

export const isInfOrNaN = (obj) => Number.isNaN(obj) || obj === Infinity || obj === -Infinity;

export const checkError = {
  maxStack: (msgError) => new RegExp("Maximum call stack size exceeded", "g").test(msgError),
};

export const handleError = (fn) =>
  function () {
    try {
      return fn.apply(this, arguments);
    } catch (error) {
      const isMaxStack = checkError.maxStack(error.message);
      if (isMaxStack) {
        throw new Error("Converting circular structure to JSON");
      }
      throw error;
    }
  };