Function shallowEqual

packages/router/src/utils/collection.ts:21–40

(
  a: {[key: string | symbol]: any},
  b: {[key: string | symbol]: any},
)

}

export function shallowEqual(
  a: {[key: string | symbol]: any},
  b: {[key: string | symbol]: any},
): boolean {
  // While `undefined` should never be possible, it would sometimes be the case in IE 11
  // and pre-chromium Edge. The check below accounts for this edge case.
  const k1 = a ? getDataKeys(a) : undefined;
  const k2 = b ? getDataKeys(b) : undefined;
  if (!k1 || !k2 || k1.length != k2.length) {
    return false;
  }
  let key: string | symbol;
  for (let i = 0; i < k1.length; i++) {
    key = k1[i];
    if (!equalArraysOrString(a[key], b[key])) {
      return false;
    }
  }
  return true;
}

/**
 * Gets the keys of an object, including `symbol` keys.