Demo

Design

Thanks to the Service Worker, we can intercept all requests in the website, and then we can return the response we want.

But, as for the secure reason, we can't register the Service Worker from a inline data url, so you have to serve the Service Worker by yourself, But i can handle the logic inside the Service Worker.

So i will split the repo into two parts, one is the client part, which handle the logic inside html, and the other is the sw part, which handle the logic inside the Service Worker.

Usage

1. Install @yrobot/sw-proxy

yarn add @yrobot/sw-proxy

2. Import @yrobot/sw-proxy/sw

service-worker.ts

import "@yrobot/sw-proxy/sw";

3. Import @yrobot/sw-proxy/client and use it

import SWProxy from "@yrobot/sw-proxy/client";

(async () => {
  // init the swProxy
  await swProxy.register();

  // set the proxy list
  await swProxy.set([
    {
      url: "/get",
      response: {
        body: "hello world",
      },
    },
    {
      url: "/post",
      method: "POST",
      response: async () => ({
        body: JSON.stringify({
          time: new Date().toLocaleString(),
          name: "sw-proxy",
        }),
        options: {
          headers: {
            "content-type": "application/json",
          },
        },
      }),
    },
    {
      url: "/image.png",
      response: {
        body: new Blob(), // image blob
      },
    },
  ] as ProxyItem[]);

  // add proxy item
  await swProxy.add([
    {
      url: "/image2.png",
      response: {
        body: new Blob(), // image blob
      },
    },
  ] as ProxyItem[]);

  // remove proxy item
  await swProxy.remove(["/image.png"] as ProxyURL[]);

  // get current active proxy list
  swProxy.list();

  // clear all proxy
  await swProxy.clear();

  // unregister the seProxy
  await swProxy.unregister();
})();

Structure

Common

type ProxyURL = string; // support RegExp later maybe

ProxyItem

interface FetchHandlerParams {
  pathname: string;
  url: string;
  search: Record<string, string>;
}

interface ResponseConstructor {
  body:
    | string
    | null
    | Blob
    | ArrayBuffer
    | DataView
    | FormData
    | ReadableStream
    | URLSearchParams;
  options?: ResponseInit;
}

interface ProxyItem {
  url: ProxyURL;
  method?: string;
  response:
    | ResponseConstructor
    | ((params: FetchHandlerParams) => Promise<ResponseConstructor>);
}