same-value.js 306 Bytes
// `SameValue` abstract operation
// https://tc39.es/ecma262/#sec-samevalue
// eslint-disable-next-line es/no-object-is -- safe
module.exports = Object.is || function is(x, y) {
  // eslint-disable-next-line no-self-compare -- NaN check
  return x === y ? x !== 0 || 1 / x === 1 / y : x != x && y != y;
};