有一个提议的 API 可能会在未来的某个时候推出（尽管它目前在 Chrome Canary 中可用，并打开了实验性网络功能标志）。它被称为 KV 存储（KV 是 Key Value 的缩写）。它具有与 localStorage API 几乎相同的接口，并将出现在 JavaScript module中。它是基于 indexeddb API 构建的，但具有更简单的 API。查看Spec似乎这也适用于 WebWorkers。有关如何使用它的示例，请参阅规范的github 页面。这是一个这样的例子：

import storage, { StorageArea } from "std:kv-storage";
import {test, assert} from "./florence-test";

test("kv-storage test",async () => {
  await storage.clear()
  await storage.set("mycat", "Tom");
  assert(await storage.get("mycat") === "Tom", "storage: mycat is Tom");

  const otherStorage = new StorageArea("unique string");
  await otherStorage.clear()
  assert(await otherStorage.get("mycat") === undefined, "otherStorage: mycat is undefined");
  await otherStorage.set("mycat", "Jerry");
  assert(await otherStorage.get("mycat") === "Jerry", "otherStorage: mycat is Jerry");
});

以下是在 Chrome Canary 中通过的测试：

虽然没有必要使用 kv-storage api，但以下代码是用于上述代码的测试框架：

// ./florence-test.js

// Ryan Florence's Basic Testing Framework modified to support async functions
// https://twitter.com/ryanflorence/status/1162792430422200320
const lock = AsyncLock();

export async function test (name, fn) {
  // we have to lock, so that console.groups are grouped together when
  // async functions are used.
  for await (const _ of lock) {
    console.group(name);
    await fn();
    console.groupEnd(name);
  }
};

export function assert (cond, desc) {
  if (cond) {
    console.log("%c✔️", "font-size: 18px; color: green", desc);
  } else {
    console.assert(cond, desc);
  }
};

// https://codereview.stackexchange.com/questions/177935/asynclock-implementation-for-js
function AsyncLock() { 
  const p = () => new Promise(next => nextIter = next ); 
  var nextIter, next = p(); 
  const nextP = () => { const result = next; next = result.then(() => p() ); return result;} 
  nextIter(); 
  return Object.assign({}, { 
    async * [Symbol.asyncIterator] () {
      try { 
        yield nextP() 
      } finally {
      nextIter() 
      } 
    }
  });
}