deep-equal.js

/*
Copyright (c) 2008-2016 Pivotal Labs

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

/* eslint-disable */

function iterableEquality(a, b) {
  if (
    typeof a !== "object" ||
    typeof b !== "object" ||
    Array.isArray(a) ||
    Array.isArray(b) ||
    a === null ||
    b === null
  ) {
    return undefined;
  }
  if (a && b && a.constructor !== b.constructor) {
    // check if the object are natives and then shallow equal them
    return a.sketchObject && b.sketchObject && a.sketchObject == b.sketchObject;
  }

  if (a.size !== undefined) {
    if (a.size !== b.size) {
      return false;
    } else if (isA("Set", a)) {
      var allFound = true;
      for (var aValue of a) {
        if (!b.has(aValue)) {
          allFound = false;
          break;
        }
      }
      if (allFound) {
        return true;
      }
    } else if (isA("Map", a)) {
      var allFound = true;
      for (var aEntry of a) {
        if (
          !b.has(aEntry[0]) ||
          !equals(aEntry[1], b.get(aEntry[0]), [iterableEquality])
        ) {
          allFound = false;
          break;
        }
      }
      if (allFound) {
        return true;
      }
    }
  }

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

  var aKeys = Object.keys(a).sort();
  var bKeys = Object.keys(b).sort();

  for (var i = 0; i < aKeys.length; i += 1) {
    var aKey = aKeys[i];
    var bKey = bKeys[i];
    if (aKey !== bKey || !equals(a[aKey], b[bKey], [iterableEquality])) {
      return false;
    }
  }

  return true;
}

function isObjectWithKeys(a) {
  return (
    a !== null &&
    typeof a === "object" &&
    !(a instanceof Error) &&
    !(a instanceof Array) &&
    !(a instanceof Date)
  );
}

function subsetEquality(object, subset) {
  if (!isObjectWithKeys(object) || !isObjectWithKeys(subset)) {
    return undefined;
  }

  return Object.keys(subset).every(function(key) {
    return (
      hasOwnProperty(object, key) &&
      equals(object[key], subset[key], [iterableEquality, subsetEquality])
    );
  });
}

// Extracted out of jasmine 2.5.2
function equals(a, b, customTesters) {
  customTesters = customTesters || [iterableEquality];
  return eq(a, b, [], [], customTesters);
}

function isAsymmetric(obj) {
  return obj && isA("Function", obj.asymmetricMatch);
}

function asymmetricMatch(a, b) {
  var asymmetricA = isAsymmetric(a),
    asymmetricB = isAsymmetric(b);

  if (asymmetricA && asymmetricB) {
    return undefined;
  }

  if (asymmetricA) {
    return a.asymmetricMatch(b);
  }

  if (asymmetricB) {
    return b.asymmetricMatch(a);
  }
}

// Equality function lovingly adapted from isEqual in
//   [Underscore](http://underscorejs.org)
function eq(a, b, aStack, bStack, customTesters) {
  var result = true;

  var asymmetricResult = asymmetricMatch(a, b);
  if (asymmetricResult !== undefined) {
    return asymmetricResult;
  }

  for (var i = 0; i < customTesters.length; i++) {
    var customTesterResult = customTesters[i](a, b);
    if (customTesterResult !== undefined) {
      return customTesterResult;
    }
  }

  if (a instanceof Error && b instanceof Error) {
    return a.message == b.message;
  }

  // Identical objects are equal. `0 === -0`, but they aren't identical.
  // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
  if (a === b) {
    return a !== 0 || 1 / a == 1 / b;
  }
  // A strict comparison is necessary because `null == undefined`.
  if (a === null || b === null) {
    return a === b;
  }
  var className = Object.prototype.toString.call(a);
  if (className != Object.prototype.toString.call(b)) {
    return false;
  }
  switch (className) {
    // Strings, numbers, dates, and booleans are compared by value.
    case "[object String]":
      // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
      // equivalent to `new String("5")`.
      return a == String(b);
    case "[object Number]":
      // `NaN`s are equivalent, but non-reflexive. An `egal` comparison is performed for
      // other numeric values.
      return a != +a ? b != +b : a === 0 ? 1 / a == 1 / b : a == +b;
    case "[object Date]":
    case "[object Boolean]":
      // Coerce dates and booleans to numeric primitive values. Dates are compared by their
      // millisecond representations. Note that invalid dates with millisecond representations
      // of `NaN` are not equivalent.
      return +a == +b;
    // RegExps are compared by their source patterns and flags.
    case "[object RegExp]":
      return (
        a.source == b.source &&
        a.global == b.global &&
        a.multiline == b.multiline &&
        a.ignoreCase == b.ignoreCase
      );
  }
  if (typeof a != "object" || typeof b != "object") {
    return false;
  }

  // Assume equality for cyclic structures. The algorithm for detecting cyclic
  // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
  var length = aStack.length;
  while (length--) {
    // Linear search. Performance is inversely proportional to the number of
    // unique nested structures.
    if (aStack[length] == a) {
      return bStack[length] == b;
    }
  }
  // Add the first object to the stack of traversed objects.
  aStack.push(a);
  bStack.push(b);
  var size = 0;
  // Recursively compare objects and arrays.
  // Compare array lengths to determine if a deep comparison is necessary.
  if (className == "[object Array]") {
    size = a.length;
    if (size !== b.length) {
      return false;
    }

    while (size--) {
      result = eq(a[size], b[size], aStack, bStack, customTesters);
      if (!result) {
        return false;
      }
    }
  }

  // Deep compare objects.
  var aKeys = keys(a, className == "[object Array]"),
    key;
  size = aKeys.length;

  // Ensure that both objects contain the same number of properties before comparing deep equality.
  if (keys(b, className == "[object Array]").length !== size) {
    return false;
  }

  while (size--) {
    key = aKeys[size];

    // Deep compare each member
    result = has(b, key) && eq(a[key], b[key], aStack, bStack, customTesters);

    if (!result) {
      return false;
    }
  }
  // Remove the first object from the stack of traversed objects.
  aStack.pop();
  bStack.pop();

  return result;
}

function keys(obj, isArray) {
  var allKeys = (function(o) {
    var keys = [];
    for (var key in o) {
      if (has(o, key)) {
        keys.push(key);
      }
    }
    return keys.concat(Object.getOwnPropertySymbols(o));
  })(obj);

  if (!isArray) {
    return allKeys;
  }

  var extraKeys = [];
  if (allKeys.length === 0) {
    return allKeys;
  }

  for (var x = 0; x < allKeys.length; x++) {
    if (!allKeys[x].match(/^[0-9]+$/)) {
      extraKeys.push(allKeys[x]);
    }
  }

  return extraKeys;
}

function has(obj, key) {
  return (
    Object.prototype.hasOwnProperty.call(obj, key) && obj[key] !== undefined
  );
}

function isA(typeName, value) {
  return Object.prototype.toString.apply(value) === "[object " + typeName + "]";
}

module.exports = equals;
module.exports.iterableEquality = iterableEquality;
module.exports.subsetEquality = subsetEquality;