lodash/lodash.unionby/index.js

/**
 * lodash 4.1.1 (Custom Build) <https://lodash.com/>
 * Build: `lodash modularize exports="npm" -o ./`
 * Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
 * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
 * Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 * Available under MIT license <https://lodash.com/license>
 */
var SetCache = require('lodash._setcache'),
    arrayIncludes = require('lodash._arrayincludes'),
    arrayIncludesWith = require('lodash._arrayincludeswith'),
    baseFlatten = require('lodash._baseflatten'),
    baseIsEqual = require('lodash._baseisequal'),
    baseIsMatch = require('lodash._baseismatch'),
    cacheHas = require('lodash._cachehas'),
    get = require('lodash.get'),
    hasIn = require('lodash.hasin'),
    rest = require('lodash.rest'),
    root = require('lodash._root'),
    toPairs = require('lodash.topairs'),
    toString = require('lodash.tostring');

/** Used to compose bitmasks for comparison styles. */
var UNORDERED_COMPARE_FLAG = 1,
    PARTIAL_COMPARE_FLAG = 2;

/** Used as the size to enable large array optimizations. */
var LARGE_ARRAY_SIZE = 200;

/** Used as references for various `Number` constants. */
var MAX_SAFE_INTEGER = 9007199254740991;

/** `Object#toString` result references. */
var funcTag = '[object Function]',
    genTag = '[object GeneratorFunction]';

/** Used to match property names within property paths. */
var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\\]|\\.)*?\1)\]/,
    reIsPlainProp = /^\w*$/,
    rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\\]|\\.)*?)\2)\]/g;

/** Used to match `RegExp` [syntax characters](http://ecma-international.org/ecma-262/6.0/#sec-patterns). */
var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;

/** Used to match backslashes in property paths. */
var reEscapeChar = /\\(\\)?/g;

/** Used to detect host constructors (Safari > 5). */
var reIsHostCtor = /^\[object .+?Constructor\]$/;

/**
 * Checks if `value` is a host object in IE < 9.
 *
 * @private
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a host object, else `false`.
 */
function isHostObject(value) {
  // Many host objects are `Object` objects that can coerce to strings
  // despite having improperly defined `toString` methods.
  var result = false;
  if (value != null && typeof value.toString != 'function') {
    try {
      result = !!(value + '');
    } catch (e) {}
  }
  return result;
}

/**
 * Converts `set` to an array.
 *
 * @private
 * @param {Object} set The set to convert.
 * @returns {Array} Returns the converted array.
 */
function setToArray(set) {
  var index = -1,
      result = Array(set.size);

  set.forEach(function(value) {
    result[++index] = value;
  });
  return result;
}

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

/** Used to resolve the decompiled source of functions. */
var funcToString = Function.prototype.toString;

/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;

/**
 * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
 * of values.
 */
var objectToString = objectProto.toString;

/** Used to detect if a method is native. */
var reIsNative = RegExp('^' +
  funcToString.call(hasOwnProperty).replace(reRegExpChar, '\\$&')
  .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
);

/* Built-in method references that are verified to be native. */
var Set = getNative(root, 'Set');

/**
 * The base implementation of `_.get` without support for default values.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {Array|string} path The path of the property to get.
 * @returns {*} Returns the resolved value.
 */
function baseGet(object, path) {
  path = isKey(path, object) ? [path + ''] : baseToPath(path);

  var index = 0,
      length = path.length;

  while (object != null && index < length) {
    object = object[path[index++]];
  }
  return (index && index == length) ? object : undefined;
}

/**
 * The base implementation of `_.iteratee`.
 *
 * @private
 * @param {*} [value=_.identity] The value to convert to an iteratee.
 * @returns {Function} Returns the iteratee.
 */
function baseIteratee(value) {
  var type = typeof value;
  if (type == 'function') {
    return value;
  }
  if (value == null) {
    return identity;
  }
  if (type == 'object') {
    return isArray(value)
      ? baseMatchesProperty(value[0], value[1])
      : baseMatches(value);
  }
  return property(value);
}

/**
 * The base implementation of `_.matches` which doesn't clone `source`.
 *
 * @private
 * @param {Object} source The object of property values to match.
 * @returns {Function} Returns the new function.
 */
function baseMatches(source) {
  var matchData = getMatchData(source);
  if (matchData.length == 1 && matchData[0][2]) {
    var key = matchData[0][0],
        value = matchData[0][1];

    return function(object) {
      if (object == null) {
        return false;
      }
      return object[key] === value &&
        (value !== undefined || (key in Object(object)));
    };
  }
  return function(object) {
    return object === source || baseIsMatch(object, source, matchData);
  };
}

/**
 * The base implementation of `_.matchesProperty` which doesn't clone `srcValue`.
 *
 * @private
 * @param {string} path The path of the property to get.
 * @param {*} srcValue The value to match.
 * @returns {Function} Returns the new function.
 */
function baseMatchesProperty(path, srcValue) {
  return function(object) {
    var objValue = get(object, path);
    return (objValue === undefined && objValue === srcValue)
      ? hasIn(object, path)
      : baseIsEqual(srcValue, objValue, undefined, UNORDERED_COMPARE_FLAG | PARTIAL_COMPARE_FLAG);
  };
}

/**
 * The base implementation of `_.property` without support for deep paths.
 *
 * @private
 * @param {string} key The key of the property to get.
 * @returns {Function} Returns the new function.
 */
function baseProperty(key) {
  return function(object) {
    return object == null ? undefined : object[key];
  };
}

/**
 * A specialized version of `baseProperty` which supports deep paths.
 *
 * @private
 * @param {Array|string} path The path of the property to get.
 * @returns {Function} Returns the new function.
 */
function basePropertyDeep(path) {
  return function(object) {
    return baseGet(object, path);
  };
}

/**
 * The base implementation of `_.toPath` which only converts `value` to a
 * path if it's not one.
 *
 * @private
 * @param {*} value The value to process.
 * @returns {Array} Returns the property path array.
 */
function baseToPath(value) {
  return isArray(value) ? value : stringToPath(value);
}

/**
 * The base implementation of `_.uniqBy` without support for iteratee shorthands.
 *
 * @private
 * @param {Array} array The array to inspect.
 * @param {Function} [iteratee] The iteratee invoked per element.
 * @param {Function} [comparator] The comparator invoked per element.
 * @returns {Array} Returns the new duplicate free array.
 */
function baseUniq(array, iteratee, comparator) {
  var index = -1,
      includes = arrayIncludes,
      length = array.length,
      isCommon = true,
      result = [],
      seen = result;

  if (comparator) {
    isCommon = false;
    includes = arrayIncludesWith;
  }
  else if (length >= LARGE_ARRAY_SIZE) {
    var set = iteratee ? null : createSet(array);
    if (set) {
      return setToArray(set);
    }
    isCommon = false;
    includes = cacheHas;
    seen = new SetCache;
  }
  else {
    seen = iteratee ? [] : result;
  }
  outer:
  while (++index < length) {
    var value = array[index],
        computed = iteratee ? iteratee(value) : value;

    if (isCommon && computed === computed) {
      var seenIndex = seen.length;
      while (seenIndex--) {
        if (seen[seenIndex] === computed) {
          continue outer;
        }
      }
      if (iteratee) {
        seen.push(computed);
      }
      result.push(value);
    }
    else if (!includes(seen, computed, comparator)) {
      if (seen !== result) {
        seen.push(computed);
      }
      result.push(value);
    }
  }
  return result;
}

/**
 * Creates a set of `values`.
 *
 * @private
 * @param {Array} values The values to add to the set.
 * @returns {Object} Returns the new set.
 */
var createSet = !(Set && new Set([1, 2]).size === 2) ? noop : function(values) {
  return new Set(values);
};

/**
 * Gets the "length" property value of `object`.
 *
 * **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792)
 * that affects Safari on at least iOS 8.1-8.3 ARM64.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {*} Returns the "length" value.
 */
var getLength = baseProperty('length');

/**
 * Gets the property names, values, and compare flags of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {Array} Returns the match data of `object`.
 */
function getMatchData(object) {
  var result = toPairs(object),
      length = result.length;

  while (length--) {
    result[length][2] = isStrictComparable(result[length][1]);
  }
  return result;
}

/**
 * Gets the native function at `key` of `object`.
 *
 * @private
 * @param {Object} object The object to query.
 * @param {string} key The key of the method to get.
 * @returns {*} Returns the function if it's native, else `undefined`.
 */
function getNative(object, key) {
  var value = object == null ? undefined : object[key];
  return isNative(value) ? value : undefined;
}

/**
 * Checks if `value` is a property name and not a property path.
 *
 * @private
 * @param {*} value The value to check.
 * @param {Object} [object] The object to query keys on.
 * @returns {boolean} Returns `true` if `value` is a property name, else `false`.
 */
function isKey(value, object) {
  if (typeof value == 'number') {
    return true;
  }
  return !isArray(value) &&
    (reIsPlainProp.test(value) || !reIsDeepProp.test(value) ||
      (object != null && value in Object(object)));
}

/**
 * Checks if `value` is suitable for strict equality comparisons, i.e. `===`.
 *
 * @private
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` if suitable for strict
 *  equality comparisons, else `false`.
 */
function isStrictComparable(value) {
  return value === value && !isObject(value);
}

/**
 * Converts `string` to a property path array.
 *
 * @private
 * @param {string} string The string to convert.
 * @returns {Array} Returns the property path array.
 */
function stringToPath(string) {
  var result = [];
  toString(string).replace(rePropName, function(match, number, quote, string) {
    result.push(quote ? string.replace(reEscapeChar, '$1') : (number || match));
  });
  return result;
}

/**
 * Gets the last element of `array`.
 *
 * @static
 * @memberOf _
 * @category Array
 * @param {Array} array The array to query.
 * @returns {*} Returns the last element of `array`.
 * @example
 *
 * _.last([1, 2, 3]);
 * // => 3
 */
function last(array) {
  var length = array ? array.length : 0;
  return length ? array[length - 1] : undefined;
}

/**
 * This method is like `_.union` except that it accepts `iteratee` which is
 * invoked for each element of each `arrays` to generate the criterion by which
 * uniqueness is computed. The iteratee is invoked with one argument: (value).
 *
 * @static
 * @memberOf _
 * @category Array
 * @param {...Array} [arrays] The arrays to inspect.
 * @param {Function|Object|string} [iteratee=_.identity] The iteratee invoked per element.
 * @returns {Array} Returns the new array of combined values.
 * @example
 *
 * _.unionBy([2.1, 1.2], [4.3, 2.4], Math.floor);
 * // => [2.1, 1.2, 4.3]
 *
 * // The `_.property` iteratee shorthand.
 * _.unionBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
 * // => [{ 'x': 1 }, { 'x': 2 }]
 */
var unionBy = rest(function(arrays) {
  var iteratee = last(arrays);
  if (isArrayLikeObject(iteratee)) {
    iteratee = undefined;
  }
  return baseUniq(baseFlatten(arrays, false, true), baseIteratee(iteratee));
});

/**
 * Checks if `value` is classified as an `Array` object.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isArray([1, 2, 3]);
 * // => true
 *
 * _.isArray(document.body.children);
 * // => false
 *
 * _.isArray('abc');
 * // => false
 *
 * _.isArray(_.noop);
 * // => false
 */
var isArray = Array.isArray;

/**
 * Checks if `value` is array-like. A value is considered array-like if it's
 * not a function and has a `value.length` that's an integer greater than or
 * equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is array-like, else `false`.
 * @example
 *
 * _.isArrayLike([1, 2, 3]);
 * // => true
 *
 * _.isArrayLike(document.body.children);
 * // => true
 *
 * _.isArrayLike('abc');
 * // => true
 *
 * _.isArrayLike(_.noop);
 * // => false
 */
function isArrayLike(value) {
  return value != null &&
    !(typeof value == 'function' && isFunction(value)) && isLength(getLength(value));
}

/**
 * This method is like `_.isArrayLike` except that it also checks if `value`
 * is an object.
 *
 * @static
 * @memberOf _
 * @type Function
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an array-like object, else `false`.
 * @example
 *
 * _.isArrayLikeObject([1, 2, 3]);
 * // => true
 *
 * _.isArrayLikeObject(document.body.children);
 * // => true
 *
 * _.isArrayLikeObject('abc');
 * // => false
 *
 * _.isArrayLikeObject(_.noop);
 * // => false
 */
function isArrayLikeObject(value) {
  return isObjectLike(value) && isArrayLike(value);
}

/**
 * Checks if `value` is classified as a `Function` object.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`.
 * @example
 *
 * _.isFunction(_);
 * // => true
 *
 * _.isFunction(/abc/);
 * // => false
 */
function isFunction(value) {
  // The use of `Object#toString` avoids issues with the `typeof` operator
  // in Safari 8 which returns 'object' for typed array constructors, and
  // PhantomJS 1.9 which returns 'function' for `NodeList` instances.
  var tag = isObject(value) ? objectToString.call(value) : '';
  return tag == funcTag || tag == genTag;
}

/**
 * Checks if `value` is a valid array-like length.
 *
 * **Note:** This function is loosely based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength).
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a valid length, else `false`.
 * @example
 *
 * _.isLength(3);
 * // => true
 *
 * _.isLength(Number.MIN_VALUE);
 * // => false
 *
 * _.isLength(Infinity);
 * // => false
 *
 * _.isLength('3');
 * // => false
 */
function isLength(value) {
  return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER;
}

/**
 * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`.
 * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is an object, else `false`.
 * @example
 *
 * _.isObject({});
 * // => true
 *
 * _.isObject([1, 2, 3]);
 * // => true
 *
 * _.isObject(_.noop);
 * // => true
 *
 * _.isObject(null);
 * // => false
 */
function isObject(value) {
  var type = typeof value;
  return !!value && (type == 'object' || type == 'function');
}

/**
 * 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 _
 * @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';
}

/**
 * Checks if `value` is a native function.
 *
 * @static
 * @memberOf _
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a native function, else `false`.
 * @example
 *
 * _.isNative(Array.prototype.push);
 * // => true
 *
 * _.isNative(_);
 * // => false
 */
function isNative(value) {
  if (value == null) {
    return false;
  }
  if (isFunction(value)) {
    return reIsNative.test(funcToString.call(value));
  }
  return isObjectLike(value) &&
    (isHostObject(value) ? reIsNative : reIsHostCtor).test(value);
}

/**
 * This method returns the first argument given to it.
 *
 * @static
 * @memberOf _
 * @category Util
 * @param {*} value Any value.
 * @returns {*} Returns `value`.
 * @example
 *
 * var object = { 'user': 'fred' };
 *
 * _.identity(object) === object;
 * // => true
 */
function identity(value) {
  return value;
}

/**
 * A no-operation function that returns `undefined` regardless of the
 * arguments it receives.
 *
 * @static
 * @memberOf _
 * @category Util
 * @example
 *
 * var object = { 'user': 'fred' };
 *
 * _.noop(object) === undefined;
 * // => true
 */
function noop() {
  // No operation performed.
}

/**
 * Creates a function that returns the value at `path` of a given object.
 *
 * @static
 * @memberOf _
 * @category Util
 * @param {Array|string} path The path of the property to get.
 * @returns {Function} Returns the new function.
 * @example
 *
 * var objects = [
 *   { 'a': { 'b': { 'c': 2 } } },
 *   { 'a': { 'b': { 'c': 1 } } }
 * ];
 *
 * _.map(objects, _.property('a.b.c'));
 * // => [2, 1]
 *
 * _.map(_.sortBy(objects, _.property(['a', 'b', 'c'])), 'a.b.c');
 * // => [1, 2]
 */
function property(path) {
  return isKey(path) ? baseProperty(path) : basePropertyDeep(path);
}

module.exports = unionBy;