comparisons.js

// Currently in sync with Node.js lib/internal/util/comparisons.js
// https://github.com/nodejs/node/commit/112cc7c27551254aa2b17098fb774867f05ed0d9
'use strict';

function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance"); }

function _iterableToArrayLimit(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

function _typeof(obj) { if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }

var regexFlagsSupported = /a/g.flags !== undefined;

var arrayFromSet = function arrayFromSet(set) {
  var array = [];
  set.forEach(function (value) {
    return array.push(value);
  });
  return array;
};

var arrayFromMap = function arrayFromMap(map) {
  var array = [];
  map.forEach(function (value, key) {
    return array.push([key, value]);
  });
  return array;
};

var objectIs = Object.is ? Object.is : require('object-is');
var objectGetOwnPropertySymbols = Object.getOwnPropertySymbols ? Object.getOwnPropertySymbols : function () {
  return [];
};
var numberIsNaN = Number.isNaN ? Number.isNaN : require('is-nan');

function uncurryThis(f) {
  return f.call.bind(f);
}

var hasOwnProperty = uncurryThis(Object.prototype.hasOwnProperty);
var propertyIsEnumerable = uncurryThis(Object.prototype.propertyIsEnumerable);
var objectToString = uncurryThis(Object.prototype.toString);

var _require$types = require('util/').types,
    isAnyArrayBuffer = _require$types.isAnyArrayBuffer,
    isArrayBufferView = _require$types.isArrayBufferView,
    isDate = _require$types.isDate,
    isMap = _require$types.isMap,
    isRegExp = _require$types.isRegExp,
    isSet = _require$types.isSet,
    isNativeError = _require$types.isNativeError,
    isBoxedPrimitive = _require$types.isBoxedPrimitive,
    isNumberObject = _require$types.isNumberObject,
    isStringObject = _require$types.isStringObject,
    isBooleanObject = _require$types.isBooleanObject,
    isBigIntObject = _require$types.isBigIntObject,
    isSymbolObject = _require$types.isSymbolObject,
    isFloat32Array = _require$types.isFloat32Array,
    isFloat64Array = _require$types.isFloat64Array;

function isNonIndex(key) {
  if (key.length === 0 || key.length > 10) return true;

  for (var i = 0; i < key.length; i++) {
    var code = key.charCodeAt(i);
    if (code < 48 || code > 57) return true;
  } // The maximum size for an array is 2 ** 32 -1.


  return key.length === 10 && key >= Math.pow(2, 32);
}

function getOwnNonIndexProperties(value) {
  return Object.keys(value).filter(isNonIndex).concat(objectGetOwnPropertySymbols(value).filter(Object.prototype.propertyIsEnumerable.bind(value)));
} // Taken from https://github.com/feross/buffer/blob/680e9e5e488f22aac27599a57dc844a6315928dd/index.js
// original notice:

/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <[email protected]> <http://feross.org>
 * @license  MIT
 */


function compare(a, b) {
  if (a === b) {
    return 0;
  }

  var x = a.length;
  var y = b.length;

  for (var i = 0, len = Math.min(x, y); i < len; ++i) {
    if (a[i] !== b[i]) {
      x = a[i];
      y = b[i];
      break;
    }
  }

  if (x < y) {
    return -1;
  }

  if (y < x) {
    return 1;
  }

  return 0;
}

var ONLY_ENUMERABLE = undefined;
var kStrict = true;
var kLoose = false;
var kNoIterator = 0;
var kIsArray = 1;
var kIsSet = 2;
var kIsMap = 3; // Check if they have the same source and flags

function areSimilarRegExps(a, b) {
  return regexFlagsSupported ? a.source === b.source && a.flags === b.flags : RegExp.prototype.toString.call(a) === RegExp.prototype.toString.call(b);
}

function areSimilarFloatArrays(a, b) {
  if (a.byteLength !== b.byteLength) {
    return false;
  }

  for (var offset = 0; offset < a.byteLength; offset++) {
    if (a[offset] !== b[offset]) {
      return false;
    }
  }

  return true;
}

function areSimilarTypedArrays(a, b) {
  if (a.byteLength !== b.byteLength) {
    return false;
  }

  return compare(new Uint8Array(a.buffer, a.byteOffset, a.byteLength), new Uint8Array(b.buffer, b.byteOffset, b.byteLength)) === 0;
}

function areEqualArrayBuffers(buf1, buf2) {
  return buf1.byteLength === buf2.byteLength && compare(new Uint8Array(buf1), new Uint8Array(buf2)) === 0;
}

function isEqualBoxedPrimitive(val1, val2) {
  if (isNumberObject(val1)) {
    return isNumberObject(val2) && objectIs(Number.prototype.valueOf.call(val1), Number.prototype.valueOf.call(val2));
  }

  if (isStringObject(val1)) {
    return isStringObject(val2) && String.prototype.valueOf.call(val1) === String.prototype.valueOf.call(val2);
  }

  if (isBooleanObject(val1)) {
    return isBooleanObject(val2) && Boolean.prototype.valueOf.call(val1) === Boolean.prototype.valueOf.call(val2);
  }

  if (isBigIntObject(val1)) {
    return isBigIntObject(val2) && BigInt.prototype.valueOf.call(val1) === BigInt.prototype.valueOf.call(val2);
  }

  return isSymbolObject(val2) && Symbol.prototype.valueOf.call(val1) === Symbol.prototype.valueOf.call(val2);
} // Notes: Type tags are historical [[Class]] properties that can be set by
// FunctionTemplate::SetClassName() in C++ or Symbol.toStringTag in JS
// and retrieved using Object.prototype.toString.call(obj) in JS
// See https://tc39.github.io/ecma262/#sec-object.prototype.tostring
// for a list of tags pre-defined in the spec.
// There are some unspecified tags in the wild too (e.g. typed array tags).
// Since tags can be altered, they only serve fast failures
//
// Typed arrays and buffers are checked by comparing the content in their
// underlying ArrayBuffer. This optimization requires that it's
// reasonable to interpret their underlying memory in the same way,
// which is checked by comparing their type tags.
// (e.g. a Uint8Array and a Uint16Array with the same memory content
// could still be different because they will be interpreted differently).
//
// For strict comparison, objects should have
// a) The same built-in type tags
// b) The same prototypes.


function innerDeepEqual(val1, val2, strict, memos) {
  // All identical values are equivalent, as determined by ===.
  if (val1 === val2) {
    if (val1 !== 0) return true;
    return strict ? objectIs(val1, val2) : true;
  } // Check more closely if val1 and val2 are equal.


  if (strict) {
    if (_typeof(val1) !== 'object') {
      return typeof val1 === 'number' && numberIsNaN(val1) && numberIsNaN(val2);
    }

    if (_typeof(val2) !== 'object' || val1 === null || val2 === null) {
      return false;
    }

    if (Object.getPrototypeOf(val1) !== Object.getPrototypeOf(val2)) {
      return false;
    }
  } else {
    if (val1 === null || _typeof(val1) !== 'object') {
      if (val2 === null || _typeof(val2) !== 'object') {
        // eslint-disable-next-line eqeqeq
        return val1 == val2;
      }

      return false;
    }

    if (val2 === null || _typeof(val2) !== 'object') {
      return false;
    }
  }

  var val1Tag = objectToString(val1);
  var val2Tag = objectToString(val2);

  if (val1Tag !== val2Tag) {
    return false;
  }

  if (Array.isArray(val1)) {
    // Check for sparse arrays and general fast path
    if (val1.length !== val2.length) {
      return false;
    }

    var keys1 = getOwnNonIndexProperties(val1, ONLY_ENUMERABLE);
    var keys2 = getOwnNonIndexProperties(val2, ONLY_ENUMERABLE);

    if (keys1.length !== keys2.length) {
      return false;
    }

    return keyCheck(val1, val2, strict, memos, kIsArray, keys1);
  } // [browserify] This triggers on certain types in IE (Map/Set) so we don't
  // wan't to early return out of the rest of the checks. However we can check
  // if the second value is one of these values and the first isn't.


  if (val1Tag === '[object Object]') {
    // return keyCheck(val1, val2, strict, memos, kNoIterator);
    if (!isMap(val1) && isMap(val2) || !isSet(val1) && isSet(val2)) {
      return false;
    }
  }

  if (isDate(val1)) {
    if (!isDate(val2) || Date.prototype.getTime.call(val1) !== Date.prototype.getTime.call(val2)) {
      return false;
    }
  } else if (isRegExp(val1)) {
    if (!isRegExp(val2) || !areSimilarRegExps(val1, val2)) {
      return false;
    }
  } else if (isNativeError(val1) || val1 instanceof Error) {
    // Do not compare the stack as it might differ even though the error itself
    // is otherwise identical.
    if (val1.message !== val2.message || val1.name !== val2.name) {
      return false;
    }
  } else if (isArrayBufferView(val1)) {
    if (!strict && (isFloat32Array(val1) || isFloat64Array(val1))) {
      if (!areSimilarFloatArrays(val1, val2)) {
        return false;
      }
    } else if (!areSimilarTypedArrays(val1, val2)) {
      return false;
    } // Buffer.compare returns true, so val1.length === val2.length. If they both
    // only contain numeric keys, we don't need to exam further than checking
    // the symbols.


    var _keys = getOwnNonIndexProperties(val1, ONLY_ENUMERABLE);

    var _keys2 = getOwnNonIndexProperties(val2, ONLY_ENUMERABLE);

    if (_keys.length !== _keys2.length) {
      return false;
    }

    return keyCheck(val1, val2, strict, memos, kNoIterator, _keys);
  } else if (isSet(val1)) {
    if (!isSet(val2) || val1.size !== val2.size) {
      return false;
    }

    return keyCheck(val1, val2, strict, memos, kIsSet);
  } else if (isMap(val1)) {
    if (!isMap(val2) || val1.size !== val2.size) {
      return false;
    }

    return keyCheck(val1, val2, strict, memos, kIsMap);
  } else if (isAnyArrayBuffer(val1)) {
    if (!areEqualArrayBuffers(val1, val2)) {
      return false;
    }
  } else if (isBoxedPrimitive(val1) && !isEqualBoxedPrimitive(val1, val2)) {
    return false;
  }

  return keyCheck(val1, val2, strict, memos, kNoIterator);
}

function getEnumerables(val, keys) {
  return keys.filter(function (k) {
    return propertyIsEnumerable(val, k);
  });
}

function keyCheck(val1, val2, strict, memos, iterationType, aKeys) {
  // For all remaining Object pairs, including Array, objects and Maps,
  // equivalence is determined by having:
  // a) The same number of owned enumerable properties
  // b) The same set of keys/indexes (although not necessarily the same order)
  // c) Equivalent values for every corresponding key/index
  // d) For Sets and Maps, equal contents
  // Note: this accounts for both named and indexed properties on Arrays.
  if (arguments.length === 5) {
    aKeys = Object.keys(val1);
    var bKeys = Object.keys(val2); // The pair must have the same number of owned properties.

    if (aKeys.length !== bKeys.length) {
      return false;
    }
  } // Cheap key test


  var i = 0;

  for (; i < aKeys.length; i++) {
    if (!hasOwnProperty(val2, aKeys[i])) {
      return false;
    }
  }

  if (strict && arguments.length === 5) {
    var symbolKeysA = objectGetOwnPropertySymbols(val1);

    if (symbolKeysA.length !== 0) {
      var count = 0;

      for (i = 0; i < symbolKeysA.length; i++) {
        var key = symbolKeysA[i];

        if (propertyIsEnumerable(val1, key)) {
          if (!propertyIsEnumerable(val2, key)) {
            return false;
          }

          aKeys.push(key);
          count++;
        } else if (propertyIsEnumerable(val2, key)) {
          return false;
        }
      }

      var symbolKeysB = objectGetOwnPropertySymbols(val2);

      if (symbolKeysA.length !== symbolKeysB.length && getEnumerables(val2, symbolKeysB).length !== count) {
        return false;
      }
    } else {
      var _symbolKeysB = objectGetOwnPropertySymbols(val2);

      if (_symbolKeysB.length !== 0 && getEnumerables(val2, _symbolKeysB).length !== 0) {
        return false;
      }
    }
  }

  if (aKeys.length === 0 && (iterationType === kNoIterator || iterationType === kIsArray && val1.length === 0 || val1.size === 0)) {
    return true;
  } // Use memos to handle cycles.


  if (memos === undefined) {
    memos = {
      val1: new Map(),
      val2: new Map(),
      position: 0
    };
  } else {
    // We prevent up to two map.has(x) calls by directly retrieving the value
    // and checking for undefined. The map can only contain numbers, so it is
    // safe to check for undefined only.
    var val2MemoA = memos.val1.get(val1);

    if (val2MemoA !== undefined) {
      var val2MemoB = memos.val2.get(val2);

      if (val2MemoB !== undefined) {
        return val2MemoA === val2MemoB;
      }
    }

    memos.position++;
  }

  memos.val1.set(val1, memos.position);
  memos.val2.set(val2, memos.position);
  var areEq = objEquiv(val1, val2, strict, aKeys, memos, iterationType);
  memos.val1.delete(val1);
  memos.val2.delete(val2);
  return areEq;
}

function setHasEqualElement(set, val1, strict, memo) {
  // Go looking.
  var setValues = arrayFromSet(set);

  for (var i = 0; i < setValues.length; i++) {
    var val2 = setValues[i];

    if (innerDeepEqual(val1, val2, strict, memo)) {
      // Remove the matching element to make sure we do not check that again.
      set.delete(val2);
      return true;
    }
  }

  return false;
} // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Equality_comparisons_and_sameness#Loose_equality_using
// Sadly it is not possible to detect corresponding values properly in case the
// type is a string, number, bigint or boolean. The reason is that those values
// can match lots of different string values (e.g., 1n == '+00001').


function findLooseMatchingPrimitives(prim) {
  switch (_typeof(prim)) {
    case 'undefined':
      return null;

    case 'object':
      // Only pass in null as object!
      return undefined;

    case 'symbol':
      return false;

    case 'string':
      prim = +prim;
    // Loose equal entries exist only if the string is possible to convert to
    // a regular number and not NaN.
    // Fall through

    case 'number':
      if (numberIsNaN(prim)) {
        return false;
      }

  }

  return true;
}

function setMightHaveLoosePrim(a, b, prim) {
  var altValue = findLooseMatchingPrimitives(prim);
  if (altValue != null) return altValue;
  return b.has(altValue) && !a.has(altValue);
}

function mapMightHaveLoosePrim(a, b, prim, item, memo) {
  var altValue = findLooseMatchingPrimitives(prim);

  if (altValue != null) {
    return altValue;
  }

  var curB = b.get(altValue);

  if (curB === undefined && !b.has(altValue) || !innerDeepEqual(item, curB, false, memo)) {
    return false;
  }

  return !a.has(altValue) && innerDeepEqual(item, curB, false, memo);
}

function setEquiv(a, b, strict, memo) {
  // This is a lazily initiated Set of entries which have to be compared
  // pairwise.
  var set = null;
  var aValues = arrayFromSet(a);

  for (var i = 0; i < aValues.length; i++) {
    var val = aValues[i]; // Note: Checking for the objects first improves the performance for object
    // heavy sets but it is a minor slow down for primitives. As they are fast
    // to check this improves the worst case scenario instead.

    if (_typeof(val) === 'object' && val !== null) {
      if (set === null) {
        set = new Set();
      } // If the specified value doesn't exist in the second set its an not null
      // object (or non strict only: a not matching primitive) we'll need to go
      // hunting for something thats deep-(strict-)equal to it. To make this
      // O(n log n) complexity we have to copy these values in a new set first.


      set.add(val);
    } else if (!b.has(val)) {
      if (strict) return false; // Fast path to detect missing string, symbol, undefined and null values.

      if (!setMightHaveLoosePrim(a, b, val)) {
        return false;
      }

      if (set === null) {
        set = new Set();
      }

      set.add(val);
    }
  }

  if (set !== null) {
    var bValues = arrayFromSet(b);

    for (var _i = 0; _i < bValues.length; _i++) {
      var _val = bValues[_i]; // We have to check if a primitive value is already
      // matching and only if it's not, go hunting for it.

      if (_typeof(_val) === 'object' && _val !== null) {
        if (!setHasEqualElement(set, _val, strict, memo)) return false;
      } else if (!strict && !a.has(_val) && !setHasEqualElement(set, _val, strict, memo)) {
        return false;
      }
    }

    return set.size === 0;
  }

  return true;
}

function mapHasEqualEntry(set, map, key1, item1, strict, memo) {
  // To be able to handle cases like:
  //   Map([[{}, 'a'], [{}, 'b']]) vs Map([[{}, 'b'], [{}, 'a']])
  // ... we need to consider *all* matching keys, not just the first we find.
  var setValues = arrayFromSet(set);

  for (var i = 0; i < setValues.length; i++) {
    var key2 = setValues[i];

    if (innerDeepEqual(key1, key2, strict, memo) && innerDeepEqual(item1, map.get(key2), strict, memo)) {
      set.delete(key2);
      return true;
    }
  }

  return false;
}

function mapEquiv(a, b, strict, memo) {
  var set = null;
  var aEntries = arrayFromMap(a);

  for (var i = 0; i < aEntries.length; i++) {
    var _aEntries$i = _slicedToArray(aEntries[i], 2),
        key = _aEntries$i[0],
        item1 = _aEntries$i[1];

    if (_typeof(key) === 'object' && key !== null) {
      if (set === null) {
        set = new Set();
      }

      set.add(key);
    } else {
      // By directly retrieving the value we prevent another b.has(key) check in
      // almost all possible cases.
      var item2 = b.get(key);

      if (item2 === undefined && !b.has(key) || !innerDeepEqual(item1, item2, strict, memo)) {
        if (strict) return false; // Fast path to detect missing string, symbol, undefined and null
        // keys.

        if (!mapMightHaveLoosePrim(a, b, key, item1, memo)) return false;

        if (set === null) {
          set = new Set();
        }

        set.add(key);
      }
    }
  }

  if (set !== null) {
    var bEntries = arrayFromMap(b);

    for (var _i2 = 0; _i2 < bEntries.length; _i2++) {
      var _bEntries$_i = _slicedToArray(bEntries[_i2], 2),
          key = _bEntries$_i[0],
          item = _bEntries$_i[1];

      if (_typeof(key) === 'object' && key !== null) {
        if (!mapHasEqualEntry(set, a, key, item, strict, memo)) return false;
      } else if (!strict && (!a.has(key) || !innerDeepEqual(a.get(key), item, false, memo)) && !mapHasEqualEntry(set, a, key, item, false, memo)) {
        return false;
      }
    }

    return set.size === 0;
  }

  return true;
}

function objEquiv(a, b, strict, keys, memos, iterationType) {
  // Sets and maps don't have their entries accessible via normal object
  // properties.
  var i = 0;

  if (iterationType === kIsSet) {
    if (!setEquiv(a, b, strict, memos)) {
      return false;
    }
  } else if (iterationType === kIsMap) {
    if (!mapEquiv(a, b, strict, memos)) {
      return false;
    }
  } else if (iterationType === kIsArray) {
    for (; i < a.length; i++) {
      if (hasOwnProperty(a, i)) {
        if (!hasOwnProperty(b, i) || !innerDeepEqual(a[i], b[i], strict, memos)) {
          return false;
        }
      } else if (hasOwnProperty(b, i)) {
        return false;
      } else {
        // Array is sparse.
        var keysA = Object.keys(a);

        for (; i < keysA.length; i++) {
          var key = keysA[i];

          if (!hasOwnProperty(b, key) || !innerDeepEqual(a[key], b[key], strict, memos)) {
            return false;
          }
        }

        if (keysA.length !== Object.keys(b).length) {
          return false;
        }

        return true;
      }
    }
  } // The pair must have equivalent values for every corresponding key.
  // Possibly expensive deep test:


  for (i = 0; i < keys.length; i++) {
    var _key = keys[i];

    if (!innerDeepEqual(a[_key], b[_key], strict, memos)) {
      return false;
    }
  }

  return true;
}

function isDeepEqual(val1, val2) {
  return innerDeepEqual(val1, val2, kLoose);
}

function isDeepStrictEqual(val1, val2) {
  return innerDeepEqual(val1, val2, kStrict);
}

module.exports = {
  isDeepEqual: isDeepEqual,
  isDeepStrictEqual: isDeepStrictEqual
};