netwerk/test/unit/test_stale-while-revalidate_positive.js

   1 /*
   2
   3 Tests the Cache-control: stale-while-revalidate response directive.
   4
   5 Purpose is to check we perform the background revalidation when the window is set
   6 and we hit it.
   7
   8 * Make request #1.
   9   - response is from the server and version=1
  10   - max-age=1, stale-while-revalidate=9999
  11 * Switch version of the data on the server and prolong the max-age to not let req #3
  12   do a bck reval at the end of the test (prevent leaks/shutdown races.)
  13 * Make request #2 in 2 seconds (entry should be expired by that time, but fall into
  14   the reval window.)
  15   - response is from the cache, version=1
  16   - a new background request should be made for the data
  17 * Wait for "http-on-background-revalidation" notifying finish of the background reval.
  18 * Make request #3.
  19   - response is from the cache, version=2
  20 * Done.
  21
  22 */
  23
  24 "use strict";
  25
  26 const { HttpServer } = ChromeUtils.importESModule(
  27   "resource://testing-common/httpd.sys.mjs"
  28 );
  29
  30 let max_age;
  31 let version;
  32 let generate_response = ver => `response version=${ver}`;
  33
  34 function test_handler(metadata, response) {
  35   const originalBody = generate_response(version);
  36   response.setHeader("Content-Type", "text/html", false);
  37   response.setHeader(
  38     "Cache-control",
  39     `max-age=${max_age}, stale-while-revalidate=9999`,
  40     false
  41   );
  42   response.setStatusLine(metadata.httpVersion, 200, "OK");
  43   response.bodyOutputStream.write(originalBody, originalBody.length);
  44 }
  45
  46 function make_channel(url) {
  47   return NetUtil.newChannel({
  48     uri: url,
  49     loadUsingSystemPrincipal: true,
  50   }).QueryInterface(Ci.nsIHttpChannel);
  51 }
  52
  53 async function get_response(channel, fromCache) {
  54   return new Promise(resolve => {
  55     channel.asyncOpen(
  56       new ChannelListener((request, buffer, ctx, isFromCache) => {
  57         Assert.equal(
  58           fromCache,
  59           isFromCache,
  60           `got response from cache = ${fromCache}`
  61         );
  62         resolve(buffer);
  63       })
  64     );
  65   });
  66 }
  67
  68 async function sleep(time) {
  69   return new Promise(resolve => {
  70     do_timeout(time * 1000, resolve);
  71   });
  72 }
  73
  74 async function stop_server(httpserver) {
  75   return new Promise(resolve => {
  76     httpserver.stop(resolve);
  77   });
  78 }
  79
  80 async function background_reval_promise() {
  81   return new Promise(resolve => {
  82     Services.obs.addObserver(resolve, "http-on-background-revalidation");
  83   });
  84 }
  85
  86 add_task(async function () {
  87   let httpserver = new HttpServer();
  88   httpserver.registerPathHandler("/testdir", test_handler);
  89   httpserver.start(-1);
  90   const PORT = httpserver.identity.primaryPort;
  91   const URI = `http://localhost:${PORT}/testdir`;
  92
  93   let response;
  94
  95   version = 1;
  96   max_age = 1;
  97   response = await get_response(make_channel(URI), false);
  98   Assert.equal(response, generate_response(1), "got response ver 1");
  99
 100   await sleep(max_age + 1);
 101
 102   // must specifically wait for the internal channel to finish the reval to make
 103   // the test race-free.
 104   let reval_done = background_reval_promise();
 105
 106   version = 2;
 107   max_age = 100;
 108   response = await get_response(make_channel(URI), true);
 109   Assert.equal(response, generate_response(1), "got response ver 1");
 110
 111   await reval_done;
 112
 113   response = await get_response(make_channel(URI), true);
 114   Assert.equal(response, generate_response(2), "got response ver 2");
 115
 116   await stop_server(httpserver);
 117 });