lodash/lodash.attempt/index.js

/**
 * lodash (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright jQuery Foundation and other contributors <https://jquery.org/>
 * Released under MIT license <https://lodash.com/license>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 */

/** `Object#toString` result references. */
var errorTag = '[object Error]';

/**
 * A faster alternative to `Function#apply`, this function invokes `func`
 * with the `this` binding of `thisArg` and the arguments of `args`.
 *
 * @private
 * @param {Function} func The function to invoke.
 * @param {*} thisArg The `this` binding of `func`.
 * @param {Array} args The arguments to invoke `func` with.
 * @returns {*} Returns the result of `func`.
 */
function apply(func, thisArg, args) {
  switch (args.length) {
    case 0: return func.call(thisArg);
    case 1: return func.call(thisArg, args[0]);
    case 2: return func.call(thisArg, args[0], args[1]);
    case 3: return func.call(thisArg, args[0], args[1], args[2]);
  }
  return func.apply(thisArg, args);
}

/** Used for built-in method references. */
var objectProto = Object.prototype;

/**
 * Used to resolve the
 * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
 * of values.
 */
var objectToString = objectProto.toString;

/* Built-in method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max;

/**
 * The base implementation of `_.rest` which doesn't validate or coerce arguments.
 *
 * @private
 * @param {Function} func The function to apply a rest parameter to.
 * @param {number} [start=func.length-1] The start position of the rest parameter.
 * @returns {Function} Returns the new function.
 */
function baseRest(func, start) {
  start = nativeMax(start === undefined ? (func.length - 1) : start, 0);
  return function() {
    var args = arguments,
        index = -1,
        length = nativeMax(args.length - start, 0),
        array = Array(length);

    while (++index < length) {
      array[index] = args[start + index];
    }
    index = -1;
    var otherArgs = Array(start + 1);
    while (++index < start) {
      otherArgs[index] = args[index];
    }
    otherArgs[start] = array;
    return apply(func, this, otherArgs);
  };
}

/**
 * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`,
 * `SyntaxError`, `TypeError`, or `URIError` object.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an error object, else `false`.
 * @example
 *
 * _.isError(new Error);
 * // => true
 *
 * _.isError(Error);
 * // => false
 */
function isError(value) {
  if (!isObjectLike(value)) {
    return false;
  }
  return (objectToString.call(value) == errorTag) ||
    (typeof value.message == 'string' && typeof value.name == 'string');
}

/**
 * Checks if `value` is object-like. A value is object-like if it's not `null`
 * and has a `typeof` result of "object".
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
 * @example
 *
 * _.isObjectLike({});
 * // => true
 *
 * _.isObjectLike([1, 2, 3]);
 * // => true
 *
 * _.isObjectLike(_.noop);
 * // => false
 *
 * _.isObjectLike(null);
 * // => false
 */
function isObjectLike(value) {
  return !!value && typeof value == 'object';
}

/**
 * Attempts to invoke `func`, returning either the result or the caught error
 * object. Any additional arguments are provided to `func` when it's invoked.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @category Util
 * @param {Function} func The function to attempt.
 * @param {...*} [args] The arguments to invoke `func` with.
 * @returns {*} Returns the `func` result or error object.
 * @example
 *
 * // Avoid throwing errors for invalid selectors.
 * var elements = _.attempt(function(selector) {
 *   return document.querySelectorAll(selector);
 * }, '>_>');
 *
 * if (_.isError(elements)) {
 *   elements = [];
 * }
 */
var attempt = baseRest(function(func, args) {
  try {
    return apply(func, undefined, args);
  } catch (e) {
    return isError(e) ? e : new Error(e);
  }
});

module.exports = attempt;