gecko-dev/toolkit/components/antitracking/test/browser/browser_blockingSessionStorage.js

AntiTracking.runTest("sessionStorage",
  async _ => {
    let shouldThrow = SpecialPowers.Services.prefs.getIntPref("network.cookie.cookieBehavior") == SpecialPowers.Ci.nsICookieService.BEHAVIOR_REJECT;

    let hasThrown;
    try {
      sessionStorage.foo = 42;
      hasThrown = false;
    } catch (e) {
      hasThrown = true;
      is(e.name, "SecurityError", "We want a security error message.");
    }

    is(hasThrown, shouldThrow, "SessionStorage show thrown only if cookieBehavior is REJECT");
  },
  async _ => {
    sessionStorage.foo = 42;
    ok(true, "SessionStorage is always allowed");
  },
  async _ => {
    await new Promise(resolve => {
      Services.clearData.deleteData(Ci.nsIClearDataService.CLEAR_ALL, value => resolve());
    });
  },
  [],
  true,
  true,
  0);

AntiTracking.runTest("sessionStorage and Storage Access API",
  async _ => {
    /* import-globals-from storageAccessAPIHelpers.js */
    await noStorageAccessInitially();

    let shouldThrow = SpecialPowers.Services.prefs.getIntPref("network.cookie.cookieBehavior") == SpecialPowers.Ci.nsICookieService.BEHAVIOR_REJECT;

    let hasThrown;
    try {
      sessionStorage.foo = 42;
      hasThrown = false;
    } catch (e) {
      hasThrown = true;
      is(e.name, "SecurityError", "We want a security error message.");
    }

    is(hasThrown, shouldThrow, "SessionStorage show thrown only if cookieBehavior is REJECT");

    /* import-globals-from storageAccessAPIHelpers.js */
    await callRequestStorageAccess();

    try {
      sessionStorage.foo = 42;
      hasThrown = false;
    } catch (e) {
      hasThrown = true;
      is(e.name, "SecurityError", "We want a security error message.");
    }

    is(hasThrown, shouldThrow, "SessionStorage show thrown only if cookieBehavior is REJECT");
  },
  async _ => {
    /* import-globals-from storageAccessAPIHelpers.js */
    await noStorageAccessInitially();

    sessionStorage.foo = 42;
    ok(true, "SessionStorage is always allowed");

    /* import-globals-from storageAccessAPIHelpers.js */
    await callRequestStorageAccess();

    // For non-tracking windows, calling the API is a no-op
    sessionStorage.foo = 42;
    ok(true, "SessionStorage is allowed after calling the storage access API too");
  },
  async _ => {
    await new Promise(resolve => {
      Services.clearData.deleteData(Ci.nsIClearDataService.CLEAR_ALL, value => resolve());
    });
  },
  null, false, false);