Function objectComparisonStart

lib/internal/util/comparisons.js:282–456

(val1, val2, mode, memos)

}

function objectComparisonStart(val1, val2, mode, memos) {
  if (mode === kStrict) {
    if (wellKnownConstructors.has(val1.constructor) ||
        (val1.constructor !== undefined && !hasOwn(val1, 'constructor'))) {
      if (val1.constructor !== val2.constructor) {
        return false;
      }
    } else if (ObjectGetPrototypeOf(val1) !== ObjectGetPrototypeOf(val2)) {
      return false;
    }
  }

  if (ArrayIsArray(val1)) {
    if (!ArrayIsArray(val2) ||
        (val1.length !== val2.length && (mode !== kPartial || val1.length < val2.length)) ||
        hasUnequalTag(val1, val2)) {
      return false;
    }

    const filter = mode !== kLoose ? ONLY_ENUMERABLE : ONLY_ENUMERABLE | SKIP_SYMBOLS;
    const keys2 = getOwnNonIndexProperties(val2, filter);
    if (mode !== kPartial &&
        keys2.length !== getOwnNonIndexProperties(val1, filter).length) {
      return false;
    }
    return keyCheck(val1, val2, mode, memos, kIsArray, keys2);
  }

  let val1Tag;
  if (val1[SymbolToStringTag] === undefined &&
      (val1Tag = ObjectPrototypeToString(val1)) === '[object Object]') {
    if (slowHasUnequalTag(val1Tag, val1, val2)) {
      return false;
    }
    return keyCheck(val1, val2, mode, memos, kNoIterator);
  } else if (isSet(val1)) {
    if (!isSet(val2) ||
        (val1.size !== val2.size && (mode !== kPartial || val1.size < val2.size)) ||
        hasUnequalTag(val1, val2)) {
      return false;
    }
    return keyCheck(val1, val2, mode, memos, kIsSet);
  } else if (isMap(val1)) {
    if (!isMap(val2) ||
        (val1.size !== val2.size && (mode !== kPartial || val1.size < val2.size)) ||
        hasUnequalTag(val1, val2)) {
      return false;
    }
    return keyCheck(val1, val2, mode, memos, kIsMap);
  } else if (isArrayBufferView(val1)) {
    if (TypedArrayPrototypeGetSymbolToStringTag(val1) !==
        TypedArrayPrototypeGetSymbolToStringTag(val2)) {
      return false;
    }
    if (mode === kPartial && val1.byteLength !== val2.byteLength) {
      if (!isPartialArrayBufferView(val1, val2)) {
        return false;
      }