browser_throttle_heuristics.js

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/* Any copyright is dedicated to the Public Domain.

 * http://creativecommons.org/publicdomain/zero/1.0/

*/

"use strict";

add_task(setup);

add_task(async function testHeuristicsThrottling() {

  // Use a zero throttle timeout for the test. This both ensures the test has a

  // short runtime as well as preventing intermittents because we thought

  // something was deterministic when it wasn't.

  let throttleTimeout = 0;

  let rateLimit = 1;

  let throttleDoneTopic = "doh:heuristics-throttle-done";

  let throttleExtendTopic = "doh:heuristics-throttle-extend";

  Preferences.set(prefs.HEURISTICS_THROTTLE_TIMEOUT_PREF, throttleTimeout);

  Preferences.set(prefs.HEURISTICS_THROTTLE_RATE_LIMIT_PREF, rateLimit);

  // Set up a passing environment and enable DoH.

  let throttledPromise = TestUtils.topicObserved(throttleDoneTopic);

  setPassingHeuristics();

  let prefPromise = TestUtils.waitForPrefChange(prefs.BREADCRUMB_PREF);

  Preferences.set(prefs.ENABLED_PREF, true);

  await prefPromise;

  is(Preferences.get(prefs.BREADCRUMB_PREF), true, "Breadcrumb saved.");

  await ensureTRRMode(2);

  info("waiting for throttle done");

  await throttledPromise;

  await checkHeuristicsTelemetry("enable_doh", "startup");

  // Change the environment to failing and simulate a network change.

  throttledPromise = TestUtils.topicObserved(throttleDoneTopic);

  simulateNetworkChange();

  info("waiting for throttle done");

  await throttledPromise;

  await checkHeuristicsTelemetry("enable_doh", "netchange");

  /* Simulate two consecutive network changes and check that we throttled the

   * second heuristics run. */

  // We wait for the throttle timer to fire twice - the first time, a fresh

  // heuristics run will be performed since it was queued while throttling.

  // This triggers another throttle timeout which is the second one we wait for.

  throttledPromise = TestUtils.topicObserved(throttleDoneTopic).then(() =>

    TestUtils.topicObserved(throttleDoneTopic)

);

  simulateNetworkChange();

  simulateNetworkChange();

  info("waiting for throttle done");

  await throttledPromise;

  await checkHeuristicsTelemetryMultiple(["netchange", "throttled"]);

  /* Simulate several consecutive network changes at a rate that exceeds the

   * rate limit and check that we only record two heuristics runs in total -

   * one for the initial netchange and one throttled run at the end. */

  // We wait for the throttle timer to be extended twice.

  let throttleExtendPromise = TestUtils.topicObserved(throttleExtendTopic);

  let throttleExtendPromise2 = throttleExtendPromise.then(() =>

    TestUtils.topicObserved(throttleExtendTopic)

);

  // Again, we wait for the timer to fire twice - once for the volatile period

  // which results in a throttled heuristics run, and once after it with no run.

  throttledPromise = throttleExtendPromise2

    .then(() => TestUtils.topicObserved(throttleDoneTopic))

    .then(() => TestUtils.topicObserved(throttleDoneTopic));

  // Simulate three network changes:

  // - The first one starts the throttle timer

  // - The second one is within the limit of 1.

  // - The third one exceeds the limit and extends the throttle period.

  simulateNetworkChange();

  simulateNetworkChange();

  simulateNetworkChange();

  // First throttle extension should happen now.

  info("waiting for throttle extend");

  await throttleExtendPromise;

  // Two more network changes to once again extend the throttle period.

  simulateNetworkChange();

  simulateNetworkChange();

  // Now the second extension should be detected.

  info("waiting for throttle done");

  await throttleExtendPromise2;

  // Finally, we wait for the throttle period to finish.

  info("waiting for throttle done");

  await throttledPromise;

  await checkHeuristicsTelemetryMultiple(["netchange", "throttled"]);

});