Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

55 files changed, 3439 insertions, 0 deletions

diff --git a/dom/localstorage/test/browser.toml b/dom/localstorage/test/browser.toml
new file mode 100644
index 0000000000..e872ba6add
--- /dev/null
+++ b/dom/localstorage/test/browser.toml
@@ -0,0 +1,5 @@
+[DEFAULT]
+skip-if = ["buildapp != 'browser'"]
+support-files = ["page_private_ls.html"]
+
+["browser_private_ls.js"]
diff --git a/dom/localstorage/test/browser_private_ls.js b/dom/localstorage/test/browser_private_ls.js
new file mode 100644
index 0000000000..5b375c90e1
--- /dev/null
+++ b/dom/localstorage/test/browser_private_ls.js
@@ -0,0 +1,44 @@
+/**
+ * This test is mainly to verify that datastores are cleared when the last
+ * private browsing context exited.
+ */
+
+async function lsCheckFunc() {
+  let storage = content.localStorage;
+
+  if (storage.length) {
+    return false;
+  }
+
+  // Store non-ASCII value to verify bug 1552428.
+  storage.setItem("foo", "úžasné");
+
+  return true;
+}
+
+function checkTabWindowLS(tab) {
+  return SpecialPowers.spawn(tab.linkedBrowser, [], lsCheckFunc);
+}
+
+add_task(async function () {
+  const pageUrl =
+    "http://example.com/browser/dom/localstorage/test/page_private_ls.html";
+
+  for (let i = 0; i < 2; i++) {
+    let privateWin = await BrowserTestUtils.openNewBrowserWindow({
+      private: true,
+    });
+
+    let privateTab = await BrowserTestUtils.openNewForegroundTab(
+      privateWin.gBrowser,
+      pageUrl
+    );
+
+    ok(
+      await checkTabWindowLS(privateTab),
+      "LS works correctly in a private-browsing page."
+    );
+
+    await BrowserTestUtils.closeWindow(privateWin);
+  }
+});
diff --git a/dom/localstorage/test/gtest/TestLocalStorage.cpp b/dom/localstorage/test/gtest/TestLocalStorage.cpp
new file mode 100644
index 0000000000..6c5621f248
--- /dev/null
+++ b/dom/localstorage/test/gtest/TestLocalStorage.cpp
@@ -0,0 +1,140 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "mozilla/NullPrincipal.h"
+#include "mozilla/dom/LocalStorageCommon.h"
+#include "mozilla/dom/StorageUtils.h"
+#include "mozilla/ipc/BackgroundUtils.h"
+#include "mozilla/ipc/PBackgroundSharedTypes.h"
+#include "nsCOMPtr.h"
+#include "nsContentUtils.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::dom::StorageUtils;
+using namespace mozilla::ipc;
+
+namespace {
+
+struct OriginKeyTest {
+  const char* mSpec;
+  const char* mOriginKey;
+  const char* mQuotaKey;
+};
+
+already_AddRefed<nsIPrincipal> GetContentPrincipal(const char* aSpec) {
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), nsDependentCString(aSpec));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  OriginAttributes attrs;
+
+  nsCOMPtr<nsIPrincipal> principal =
+      BasePrincipal::CreateContentPrincipal(uri, attrs);
+
+  return principal.forget();
+}
+
+void CheckGeneratedOriginKey(nsIPrincipal* aPrincipal, const char* aOriginKey,
+                             const char* aQuotaKey) {
+  nsCString originAttrSuffix;
+  nsCString originKey;
+  nsCString quotaKey;
+
+  aPrincipal->OriginAttributesRef().CreateSuffix(originAttrSuffix);
+
+  nsresult rv = aPrincipal->GetStorageOriginKey(originKey);
+  if (aOriginKey) {
+    ASSERT_EQ(rv, NS_OK) << "GetStorageOriginKey should not fail";
+    EXPECT_TRUE(originKey == nsDependentCString(aOriginKey));
+  } else {
+    ASSERT_NE(rv, NS_OK) << "GetStorageOriginKey should fail";
+  }
+
+  rv = aPrincipal->GetLocalStorageQuotaKey(quotaKey);
+  if (aQuotaKey) {
+    ASSERT_EQ(rv, NS_OK) << "GetLocalStorageQuotaKey should not fail";
+    EXPECT_TRUE(quotaKey == nsDependentCString(aQuotaKey));
+  } else {
+    ASSERT_NE(rv, NS_OK) << "GetLocalStorageQuotaKey should fail";
+  }
+
+  PrincipalInfo principalInfo;
+  rv = PrincipalToPrincipalInfo(aPrincipal, &principalInfo);
+  ASSERT_EQ(rv, NS_OK) << "PrincipalToPrincipalInfo should not fail";
+
+  const auto res = GenerateOriginKey2(principalInfo);
+  if (aOriginKey) {
+    ASSERT_TRUE(res.isOk())
+    << "GenerateOriginKey2 should not fail";
+    EXPECT_TRUE(res.inspect().second == nsDependentCString(aOriginKey));
+  } else {
+    ASSERT_TRUE(res.isErr())
+    << "GenerateOriginKey2 should fail";
+  }
+}
+
+}  // namespace
+
+TEST(LocalStorage, OriginKey)
+{
+  // Check the system principal.
+  nsCOMPtr<nsIScriptSecurityManager> secMan =
+      nsContentUtils::GetSecurityManager();
+  ASSERT_TRUE(secMan)
+  << "GetSecurityManager() should not fail";
+
+  nsCOMPtr<nsIPrincipal> principal;
+  secMan->GetSystemPrincipal(getter_AddRefs(principal));
+  ASSERT_TRUE(principal)
+  << "GetSystemPrincipal() should not fail";
+
+  CheckGeneratedOriginKey(principal, nullptr, nullptr);
+
+  // Check the null principal.
+  principal = NullPrincipal::CreateWithoutOriginAttributes();
+  ASSERT_TRUE(principal)
+  << "CreateWithoutOriginAttributes() should not fail";
+
+  CheckGeneratedOriginKey(principal, nullptr, nullptr);
+
+  // Check content principals.
+  static const OriginKeyTest tests[] = {
+      {"http://localhost", "tsohlacol.:http:80", ":tsohlacol."},
+      {"http://www.mozilla.org", "gro.allizom.www.:http:80", ":gro.allizom."},
+      {"https://www.mozilla.org", "gro.allizom.www.:https:443",
+       ":gro.allizom."},
+      {"http://www.mozilla.org:32400", "gro.allizom.www.:http:32400",
+       ":gro.allizom."},
+      {"file:///Users/Joe/Sites/", "/setiS/eoJ/sresU/.:file",
+       ":/setiS/eoJ/sresU/."},
+      {"file:///Users/Joe/Sites/#foo", "/setiS/eoJ/sresU/.:file",
+       ":/setiS/eoJ/sresU/."},
+      {"file:///Users/Joe/Sites/?foo", "/setiS/eoJ/sresU/.:file",
+       ":/setiS/eoJ/sresU/."},
+      {"file:///Users/Joe/Sites", "/eoJ/sresU/.:file", ":/eoJ/sresU/."},
+      {"file:///Users/Joe/Sites#foo", "/eoJ/sresU/.:file", ":/eoJ/sresU/."},
+      {"file:///Users/Joe/Sites?foo", "/eoJ/sresU/.:file", ":/eoJ/sresU/."},
+      {"moz-extension://53711a8f-65ed-e742-9671-1f02e267c0bc/"
+       "_generated_background_page.html",
+       "cb0c762e20f1-1769-247e-de56-f8a11735.:moz-extension",
+       ":cb0c762e20f1-1769-247e-de56-f8a11735."},
+      {"http://[::1]:8/test.html", "1::.:http:8", ":1::."},
+  };
+
+  for (const auto& test : tests) {
+    principal = GetContentPrincipal(test.mSpec);
+    ASSERT_TRUE(principal)
+    << "GetContentPrincipal() should not fail";
+
+    CheckGeneratedOriginKey(principal, test.mOriginKey, test.mQuotaKey);
+  }
+}
diff --git a/dom/localstorage/test/gtest/moz.build b/dom/localstorage/test/gtest/moz.build
new file mode 100644
index 0000000000..f9d3c7bb0b
--- /dev/null
+++ b/dom/localstorage/test/gtest/moz.build
@@ -0,0 +1,17 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES = [
+    "TestLocalStorage.cpp",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul-gtest"
+
+LOCAL_INCLUDES += [
+    "/dom/localstorage",
+]
diff --git a/dom/localstorage/test/helpers.js b/dom/localstorage/test/helpers.js
new file mode 100644
index 0000000000..f9dbdd21dc
--- /dev/null
+++ b/dom/localstorage/test/helpers.js
@@ -0,0 +1,78 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+// testSteps is expected to be defined by the test using this file.
+/* global testSteps:false */
+
+function executeSoon(aFun) {
+  SpecialPowers.Services.tm.dispatchToMainThread({
+    run() {
+      aFun();
+    },
+  });
+}
+
+function clearAllDatabases() {
+  let qms = SpecialPowers.Services.qms;
+  let principal = SpecialPowers.wrap(document).nodePrincipal;
+  let request = qms.clearStoragesForPrincipal(principal);
+  return request;
+}
+
+if (!window.runTest) {
+  window.runTest = async function () {
+    SimpleTest.waitForExplicitFinish();
+
+    info("Pushing preferences");
+
+    await SpecialPowers.pushPrefEnv({
+      set: [
+        ["dom.storage.testing", true],
+        ["dom.quotaManager.testing", true],
+      ],
+    });
+
+    info("Clearing old databases");
+
+    await requestFinished(clearAllDatabases());
+
+    SimpleTest.registerCleanupFunction(async function () {
+      await requestFinished(clearAllDatabases());
+    });
+  };
+}
+
+function returnToEventLoop() {
+  return new Promise(function (resolve) {
+    executeSoon(resolve);
+  });
+}
+
+function getLocalStorage() {
+  return localStorage;
+}
+
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
+async function requestFinished(request) {
+  await new Promise(function (resolve) {
+    request.callback = SpecialPowers.wrapCallback(function () {
+      resolve();
+    });
+  });
+
+  if (request.resultCode !== SpecialPowers.Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
+}
diff --git a/dom/localstorage/test/mochitest.toml b/dom/localstorage/test/mochitest.toml
new file mode 100644
index 0000000000..403207218e
--- /dev/null
+++ b/dom/localstorage/test/mochitest.toml
@@ -0,0 +1,11 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+[DEFAULT]
+support-files = [
+  "helpers.js",
+  "unit/test_largeItems.js",
+]
+
+["test_largeItems.html"]
diff --git a/dom/localstorage/test/page_private_ls.html b/dom/localstorage/test/page_private_ls.html
new file mode 100644
index 0000000000..795a814981
--- /dev/null
+++ b/dom/localstorage/test/page_private_ls.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html>
+<head>
+  <meta charset="utf-8">
+</head>
+<body>
+  All the interesting stuff happens in ContentTask.spawn() calls.
+</body>
+</html>
diff --git a/dom/localstorage/test/test_largeItems.html b/dom/localstorage/test/test_largeItems.html
new file mode 100644
index 0000000000..92316085fc
--- /dev/null
+++ b/dom/localstorage/test/test_largeItems.html
@@ -0,0 +1,19 @@
+<!--
+  Any copyright is dedicated to the Public Domain.
+  http://creativecommons.org/publicdomain/zero/1.0/
+-->
+<html>
+<head>
+  <title>Large Items Test</title>
+
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+
+  <script type="text/javascript" src="unit/test_largeItems.js"></script>
+  <script type="text/javascript" src="helpers.js"></script>
+
+</head>
+
+<body onload="runTest();"></body>
+
+</html>
diff --git a/dom/localstorage/test/unit/archive_profile.zip b/dom/localstorage/test/unit/archive_profile.zip
new file mode 100644
index 0000000000..71b2d1e5f9
--- /dev/null
+++ b/dom/localstorage/test/unit/archive_profile.zip
diff --git a/dom/localstorage/test/unit/corruptedDatabase_missingUsageFile_profile.zip b/dom/localstorage/test/unit/corruptedDatabase_missingUsageFile_profile.zip
new file mode 100644
index 0000000000..8cfa6e3d43
--- /dev/null
+++ b/dom/localstorage/test/unit/corruptedDatabase_missingUsageFile_profile.zip
diff --git a/dom/localstorage/test/unit/corruptedDatabase_profile.zip b/dom/localstorage/test/unit/corruptedDatabase_profile.zip
new file mode 100644
index 0000000000..2f60db2a45
--- /dev/null
+++ b/dom/localstorage/test/unit/corruptedDatabase_profile.zip
diff --git a/dom/localstorage/test/unit/databaseShadowing-shared.js b/dom/localstorage/test/unit/databaseShadowing-shared.js
new file mode 100644
index 0000000000..ffee8579cb
--- /dev/null
+++ b/dom/localstorage/test/unit/databaseShadowing-shared.js
@@ -0,0 +1,130 @@
+/* import-globals-from head.js */
+
+const principalInfos = [
+  { url: "http://example.com", attrs: {} },
+
+  { url: "http://origin.test", attrs: {} },
+
+  { url: "http://prefix.test", attrs: {} },
+  { url: "http://prefix.test", attrs: { userContextId: 10 } },
+
+  { url: "http://pattern.test", attrs: { userContextId: 15 } },
+  { url: "http://pattern.test:8080", attrs: { userContextId: 15 } },
+  { url: "https://pattern.test", attrs: { userContextId: 15 } },
+];
+
+const surrogate = String.fromCharCode(0xdc00);
+const replacement = String.fromCharCode(0xfffd);
+const beginning = "beginning";
+const ending = "ending";
+const complexValue = beginning + surrogate + surrogate + ending;
+const corruptedValue = beginning + replacement + replacement + ending;
+
+function enableNextGenLocalStorage() {
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+}
+
+function disableNextGenLocalStorage() {
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    true
+  );
+}
+
+function storeData() {
+  for (let i = 0; i < principalInfos.length; i++) {
+    let principalInfo = principalInfos[i];
+    let principal = getPrincipal(principalInfo.url, principalInfo.attrs);
+
+    info("Getting storage");
+
+    let storage = getLocalStorage(principal);
+
+    info("Adding data");
+
+    storage.setItem("key0", "value0");
+    storage.clear();
+    storage.setItem("key1", "value1");
+    storage.removeItem("key1");
+    storage.setItem("key2", "value2");
+    storage.setItem("complexKey", complexValue);
+
+    info("Closing storage");
+
+    storage.close();
+  }
+}
+
+function exportShadowDatabase(name) {
+  info("Verifying shadow database");
+
+  let profileDir = Services.dirsvc.get("ProfD", Ci.nsIFile);
+  let shadowDatabase = profileDir.clone();
+  shadowDatabase.append("webappsstore.sqlite");
+
+  let exists = shadowDatabase.exists();
+  ok(exists, "Shadow database does exist");
+
+  info("Copying shadow database");
+
+  let currentDir = Services.dirsvc.get("CurWorkD", Ci.nsIFile);
+  shadowDatabase.copyTo(currentDir, name);
+}
+
+function importShadowDatabase(name) {
+  info("Verifying shadow database");
+
+  let currentDir = Services.dirsvc.get("CurWorkD", Ci.nsIFile);
+  let shadowDatabase = currentDir.clone();
+  shadowDatabase.append(name);
+
+  let exists = shadowDatabase.exists();
+  if (!exists) {
+    return false;
+  }
+
+  info("Copying shadow database");
+
+  let profileDir = Services.dirsvc.get("ProfD", Ci.nsIFile);
+  shadowDatabase.copyTo(profileDir, "webappsstore.sqlite");
+
+  return true;
+}
+
+function verifyData(clearedOrigins, migrated = false) {
+  for (let i = 0; i < principalInfos.length; i++) {
+    let principalInfo = principalInfos[i];
+    let principal = getPrincipal(principalInfo.url, principalInfo.attrs);
+
+    info("Getting storage");
+
+    let storage = getLocalStorage(principal);
+
+    info("Verifying data");
+
+    if (clearedOrigins.includes(i)) {
+      ok(storage.getItem("key2") == null, "Correct value");
+      ok(storage.getItem("complexKey") == null, "Correct value");
+    } else {
+      ok(storage.getItem("key0") == null, "Correct value");
+      ok(storage.getItem("key1") == null, "Correct value");
+      is(storage.getItem("key2"), "value2", "Correct value");
+      is(
+        storage.getItem("complexKey"),
+        migrated ? corruptedValue : complexValue,
+        "Correct value"
+      );
+    }
+
+    info("Closing storage");
+
+    storage.close();
+  }
+}
diff --git a/dom/localstorage/test/unit/groupMismatch_profile.zip b/dom/localstorage/test/unit/groupMismatch_profile.zip
new file mode 100644
index 0000000000..182b013de0
--- /dev/null
+++ b/dom/localstorage/test/unit/groupMismatch_profile.zip
diff --git a/dom/localstorage/test/unit/head.js b/dom/localstorage/test/unit/head.js
new file mode 100644
index 0000000000..cd84f14164
--- /dev/null
+++ b/dom/localstorage/test/unit/head.js
@@ -0,0 +1,328 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+// Tests are expected to define testSteps.
+/* globals testSteps */
+
+const NS_ERROR_DOM_QUOTA_EXCEEDED_ERR = 22;
+
+function is(a, b, msg) {
+  Assert.equal(a, b, msg);
+}
+
+function ok(cond, msg) {
+  Assert.ok(!!cond, msg);
+}
+
+add_setup(function () {
+  do_get_profile();
+
+  enableTesting();
+
+  registerCleanupFunction(resetTesting);
+});
+
+function returnToEventLoop() {
+  return new Promise(function (resolve) {
+    executeSoon(resolve);
+  });
+}
+
+function enableTesting() {
+  Services.prefs.setBoolPref("dom.simpleDB.enabled", true);
+  Services.prefs.setBoolPref("dom.storage.testing", true);
+
+  // xpcshell globals don't have associated clients in the Clients API sense, so
+  // we need to disable client validation so that the unit tests are allowed to
+  // use LocalStorage.
+  Services.prefs.setBoolPref("dom.storage.client_validation", false);
+
+  Services.prefs.setBoolPref("dom.quotaManager.testing", true);
+}
+
+function resetTesting() {
+  Services.prefs.clearUserPref("dom.quotaManager.testing");
+  Services.prefs.clearUserPref("dom.storage.client_validation");
+  Services.prefs.clearUserPref("dom.storage.testing");
+  Services.prefs.clearUserPref("dom.simpleDB.enabled");
+}
+
+function setGlobalLimit(globalLimit) {
+  Services.prefs.setIntPref(
+    "dom.quotaManager.temporaryStorage.fixedLimit",
+    globalLimit
+  );
+}
+
+function resetGlobalLimit() {
+  Services.prefs.clearUserPref("dom.quotaManager.temporaryStorage.fixedLimit");
+}
+
+function setOriginLimit(originLimit) {
+  Services.prefs.setIntPref("dom.storage.default_quota", originLimit);
+}
+
+function resetOriginLimit() {
+  Services.prefs.clearUserPref("dom.storage.default_quota");
+}
+
+function setTimeout(callback, timeout) {
+  let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+
+  timer.initWithCallback(
+    {
+      notify() {
+        callback();
+      },
+    },
+    timeout,
+    Ci.nsITimer.TYPE_ONE_SHOT
+  );
+
+  return timer;
+}
+
+function initStorage() {
+  return Services.qms.init();
+}
+
+function initTemporaryStorage() {
+  return Services.qms.initTemporaryStorage();
+}
+
+function initPersistentOrigin(principal) {
+  return Services.qms.initializePersistentOrigin(principal);
+}
+
+function initTemporaryOrigin(persistence, principal) {
+  return Services.qms.initializeTemporaryOrigin(persistence, principal);
+}
+
+function getOriginUsage(principal, fromMemory = false) {
+  let request = Services.qms.getUsageForPrincipal(
+    principal,
+    function () {},
+    fromMemory
+  );
+
+  return request;
+}
+
+function clear() {
+  let request = Services.qms.clear();
+
+  return request;
+}
+
+function clearOriginsByPattern(pattern) {
+  let request = Services.qms.clearStoragesForOriginAttributesPattern(pattern);
+
+  return request;
+}
+
+function clearOriginsByPrefix(principal, persistence) {
+  let request = Services.qms.clearStoragesForOriginPrefix(
+    principal,
+    persistence
+  );
+
+  return request;
+}
+
+function clearOrigin(principal, persistence) {
+  let request = Services.qms.clearStoragesForPrincipal(principal, persistence);
+
+  return request;
+}
+
+function reset() {
+  let request = Services.qms.reset();
+
+  return request;
+}
+
+function resetOrigin(principal) {
+  let request = Services.qms.resetStoragesForPrincipal(
+    principal,
+    "default",
+    "ls"
+  );
+
+  return request;
+}
+
+function installPackage(packageName) {
+  let currentDir = Services.dirsvc.get("CurWorkD", Ci.nsIFile);
+
+  let packageFile = currentDir.clone();
+  packageFile.append(packageName + ".zip");
+
+  let zipReader = Cc["@mozilla.org/libjar/zip-reader;1"].createInstance(
+    Ci.nsIZipReader
+  );
+  zipReader.open(packageFile);
+
+  let entryNames = [];
+  let entries = zipReader.findEntries(null);
+  while (entries.hasMore()) {
+    let entry = entries.getNext();
+    entryNames.push(entry);
+  }
+  entryNames.sort();
+
+  for (let entryName of entryNames) {
+    let zipentry = zipReader.getEntry(entryName);
+
+    let file = getRelativeFile(entryName);
+
+    if (zipentry.isDirectory) {
+      file.create(Ci.nsIFile.DIRECTORY_TYPE, parseInt("0755", 8));
+    } else {
+      let istream = zipReader.getInputStream(entryName);
+
+      var ostream = Cc[
+        "@mozilla.org/network/file-output-stream;1"
+      ].createInstance(Ci.nsIFileOutputStream);
+      ostream.init(file, -1, parseInt("0644", 8), 0);
+
+      let bostream = Cc[
+        "@mozilla.org/network/buffered-output-stream;1"
+      ].createInstance(Ci.nsIBufferedOutputStream);
+      bostream.init(ostream, 32768);
+
+      bostream.writeFrom(istream, istream.available());
+
+      istream.close();
+      bostream.close();
+    }
+  }
+
+  zipReader.close();
+}
+
+function getProfileDir() {
+  return Services.dirsvc.get("ProfD", Ci.nsIFile);
+}
+
+// Given a "/"-delimited path relative to the profile directory,
+// return an nsIFile representing the path.  This does not test
+// for the existence of the file or parent directories.
+// It is safe even on Windows where the directory separator is not "/",
+// but make sure you're not passing in a "\"-delimited path.
+function getRelativeFile(relativePath) {
+  let profileDir = getProfileDir();
+
+  let file = profileDir.clone();
+  relativePath.split("/").forEach(function (component) {
+    file.append(component);
+  });
+
+  return file;
+}
+
+function repeatChar(count, ch) {
+  if (count == 0) {
+    return "";
+  }
+
+  let result = ch;
+  let count2 = count / 2;
+
+  // Double the input until it is long enough.
+  while (result.length <= count2) {
+    result += result;
+  }
+
+  // Use substring to hit the precise length target without using extra memory.
+  return result + result.substring(0, count - result.length);
+}
+
+function getPrincipal(url, attrs) {
+  let uri = Services.io.newURI(url);
+  if (!attrs) {
+    attrs = {};
+  }
+  return Services.scriptSecurityManager.createContentPrincipal(uri, attrs);
+}
+
+function getCurrentPrincipal() {
+  return Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal);
+}
+
+function getDefaultPrincipal() {
+  return getPrincipal("http://example.com");
+}
+
+function getSimpleDatabase(principal, persistence) {
+  let connection = Cc["@mozilla.org/dom/sdb-connection;1"].createInstance(
+    Ci.nsISDBConnection
+  );
+
+  if (!principal) {
+    principal = getDefaultPrincipal();
+  }
+
+  connection.init(principal, persistence);
+
+  return connection;
+}
+
+function getLocalStorage(principal) {
+  if (!principal) {
+    principal = getDefaultPrincipal();
+  }
+
+  return Services.domStorageManager.createStorage(
+    null,
+    principal,
+    principal,
+    ""
+  );
+}
+
+class RequestError extends Error {
+  constructor(resultCode, resultName) {
+    super(`Request failed (code: ${resultCode}, name: ${resultName})`);
+    this.name = "RequestError";
+    this.resultCode = resultCode;
+    this.resultName = resultName;
+  }
+}
+
+async function requestFinished(request) {
+  await new Promise(function (resolve) {
+    request.callback = function () {
+      resolve();
+    };
+  });
+
+  if (request.resultCode !== Cr.NS_OK) {
+    throw new RequestError(request.resultCode, request.resultName);
+  }
+
+  return request.result;
+}
+
+function loadSubscript(path) {
+  let file = do_get_file(path, false);
+  let uri = Services.io.newFileURI(file);
+  Services.scriptloader.loadSubScript(uri.spec);
+}
+
+async function readUsageFromUsageFile(usageFile) {
+  let file = await File.createFromNsIFile(usageFile);
+
+  let buffer = await new Promise(resolve => {
+    let reader = new FileReader();
+    reader.onloadend = () => resolve(reader.result);
+    reader.readAsArrayBuffer(file);
+  });
+
+  // Manually getting the lower 32-bits because of the lack of support for
+  // 64-bit values currently from DataView/JS (other than the BigInt support
+  // that's currently behind a flag).
+  let view = new DataView(buffer, 8, 4);
+  return view.getUint32();
+}
diff --git a/dom/localstorage/test/unit/make_migration_emptyValue.js b/dom/localstorage/test/unit/make_migration_emptyValue.js
new file mode 100644
index 0000000000..12484ad7f3
--- /dev/null
+++ b/dom/localstorage/test/unit/make_migration_emptyValue.js
@@ -0,0 +1,23 @@
+/*
+  Any copyright is dedicated to the Public Domain.
+  http://creativecommons.org/publicdomain/zero/1.0/
+*/
+
+async function testSteps() {
+  const data = {
+    key: "foo",
+    value: "",
+  };
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", false);
+
+  info("Getting storage");
+
+  const storage = getLocalStorage();
+
+  info("Adding data");
+
+  storage.setItem(data.key, data.value);
+}
diff --git a/dom/localstorage/test/unit/migration_emptyValue_profile.zip b/dom/localstorage/test/unit/migration_emptyValue_profile.zip
new file mode 100644
index 0000000000..b829beae77
--- /dev/null
+++ b/dom/localstorage/test/unit/migration_emptyValue_profile.zip
diff --git a/dom/localstorage/test/unit/migration_profile.zip b/dom/localstorage/test/unit/migration_profile.zip
new file mode 100644
index 0000000000..19dc3d4805
--- /dev/null
+++ b/dom/localstorage/test/unit/migration_profile.zip
diff --git a/dom/localstorage/test/unit/schema3upgrade_profile.zip b/dom/localstorage/test/unit/schema3upgrade_profile.zip
new file mode 100644
index 0000000000..1ee9bfbf2e
--- /dev/null
+++ b/dom/localstorage/test/unit/schema3upgrade_profile.zip
diff --git a/dom/localstorage/test/unit/schema4upgrade_profile.zip b/dom/localstorage/test/unit/schema4upgrade_profile.zip
new file mode 100644
index 0000000000..ae8ba09606
--- /dev/null
+++ b/dom/localstorage/test/unit/schema4upgrade_profile.zip
diff --git a/dom/localstorage/test/unit/stringLength2_profile.zip b/dom/localstorage/test/unit/stringLength2_profile.zip
new file mode 100644
index 0000000000..de4d0fc3aa
--- /dev/null
+++ b/dom/localstorage/test/unit/stringLength2_profile.zip
diff --git a/dom/localstorage/test/unit/stringLength_profile.zip b/dom/localstorage/test/unit/stringLength_profile.zip
new file mode 100644
index 0000000000..6cac890860
--- /dev/null
+++ b/dom/localstorage/test/unit/stringLength_profile.zip
diff --git a/dom/localstorage/test/unit/test_archive.js b/dom/localstorage/test/unit/test_archive.js
new file mode 100644
index 0000000000..86e59d73c8
--- /dev/null
+++ b/dom/localstorage/test/unit/test_archive.js
@@ -0,0 +1,78 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const lsArchiveFile = "storage/ls-archive.sqlite";
+
+  const principalInfo = {
+    url: "http://example.com",
+    attrs: {},
+  };
+
+  function checkStorage() {
+    let principal = getPrincipal(principalInfo.url, principalInfo.attrs);
+    let storage = getLocalStorage(principal);
+    try {
+      storage.open();
+      ok(true, "Did not throw");
+    } catch (ex) {
+      ok(false, "Should not have thrown");
+    }
+  }
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", true);
+
+  info("Sub test case 1 - Archive file is a directory.");
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  let archiveFile = getRelativeFile(lsArchiveFile);
+
+  archiveFile.create(Ci.nsIFile.DIRECTORY_TYPE, parseInt("0755", 8));
+
+  checkStorage();
+
+  info("Sub test case 2 - Corrupted archive file.");
+
+  info("Clearing");
+
+  request = clear();
+  await requestFinished(request);
+
+  let ostream = Cc["@mozilla.org/network/file-output-stream;1"].createInstance(
+    Ci.nsIFileOutputStream
+  );
+  ostream.init(archiveFile, -1, parseInt("0644", 8), 0);
+  ostream.write("foobar", 6);
+  ostream.close();
+
+  checkStorage();
+
+  info("Sub test case 3 - Nonupdateable archive file.");
+
+  info("Clearing");
+
+  request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains storage.sqlite and storage/ls-archive.sqlite
+  // storage/ls-archive.sqlite was taken from FF 54 to force an upgrade.
+  // There's just one record in the webappsstore2 table. The record was
+  // modified by renaming the origin attribute userContextId to userContextKey.
+  // This triggers an error during the upgrade.
+  installPackage("archive_profile");
+
+  let fileSize = archiveFile.fileSize;
+  Assert.greater(fileSize, 0, "archive file size is greater than zero");
+
+  checkStorage();
+});
diff --git a/dom/localstorage/test/unit/test_clientValidation.js b/dom/localstorage/test/unit/test_clientValidation.js
new file mode 100644
index 0000000000..26dc2bfdf7
--- /dev/null
+++ b/dom/localstorage/test/unit/test_clientValidation.js
@@ -0,0 +1,32 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * Because this is an xpcshell global, it does not have an associated client id.
+ * We turn on client validation for LocalStorage and ensure that we don't have
+ * access to LocalStorage.
+ */
+add_task(async function testSteps() {
+  const principal = getPrincipal("http://example.com");
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+  Services.prefs.setBoolPref("dom.storage.client_validation", true);
+
+  info("Getting storage");
+
+  try {
+    getLocalStorage(principal);
+    ok(false, "Should have thrown");
+  } catch (ex) {
+    ok(true, "Did throw");
+    is(ex.name, "NS_ERROR_FAILURE", "Threw right Exception");
+    is(ex.result, Cr.NS_ERROR_FAILURE, "Threw with right result");
+  }
+});
diff --git a/dom/localstorage/test/unit/test_corruptedDatabase.js b/dom/localstorage/test/unit/test_corruptedDatabase.js
new file mode 100644
index 0000000000..3b28b0f8be
--- /dev/null
+++ b/dom/localstorage/test/unit/test_corruptedDatabase.js
@@ -0,0 +1,73 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+async function doTest(profile) {
+  info("Testing profile " + profile);
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  installPackage(profile);
+
+  const principal = getPrincipal("http://example.org");
+
+  let storage = getLocalStorage(principal);
+
+  let length = storage.length;
+
+  Assert.strictEqual(length, 0, "Correct length");
+
+  info("Resetting origin");
+
+  request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, 0, "Correct usage");
+}
+
+add_task(async function testSteps() {
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  // XXX This should be refactored into separate sub test cases.
+
+  const profiles = [
+    // This profile contains one localStorage, all localStorage related files, a
+    // script for localStorage creation and the storage database:
+    // - storage/default/http+++example.org/ls
+    // - storage/ls-archive.sqlite
+    // - create_db.js
+    // - storage.sqlite
+    // - webappsstore.sqlite
+    // The file create_db.js in the package was run locally, specifically it was
+    // temporarily added to xpcshell.ini and then executed:
+    //   mach xpcshell-test --interactive dom/localstorage/test/unit/create_db.js
+    // Note: to make it become the profile in the test, additional manual steps
+    // are needed.
+    // 1. Manually change first 6 chars in data.sqlite to "foobar".
+    // 2. Remove the folder "storage/temporary".
+    "corruptedDatabase_profile",
+    // This profile is the same as corruptedDatabase_profile, except that the usage
+    // file (storage/default/http+++example.org/ls/usage) is missing.
+    "corruptedDatabase_missingUsageFile_profile",
+  ];
+
+  for (const profile of profiles) {
+    await doTest(profile);
+  }
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing1.js b/dom/localstorage/test/unit/test_databaseShadowing1.js
new file mode 100644
index 0000000000..8582f434fc
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing1.js
@@ -0,0 +1,23 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  enableNextGenLocalStorage();
+
+  storeData();
+
+  verifyData([]);
+
+  // Wait for all database connections to close.
+  let request = reset();
+  await requestFinished(request);
+
+  exportShadowDatabase("shadowdb.sqlite");
+
+  // The shadow database is now prepared for test_databaseShadowing2.js
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing2.js b/dom/localstorage/test/unit/test_databaseShadowing2.js
new file mode 100644
index 0000000000..f7b0ddb1a2
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing2.js
@@ -0,0 +1,17 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  // The shadow database was prepared in test_databaseShadowing1.js
+
+  disableNextGenLocalStorage();
+
+  ok(importShadowDatabase("shadowdb.sqlite"), "Import succeeded");
+
+  verifyData([], /* migrated */ true);
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin1.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin1.js
new file mode 100644
index 0000000000..d88fde52e5
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin1.js
@@ -0,0 +1,30 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  enableNextGenLocalStorage();
+
+  storeData();
+
+  verifyData([]);
+
+  let principal = getPrincipal("http://origin.test", {});
+  let request = clearOrigin(principal, "default");
+  await requestFinished(request);
+
+  verifyData([1]);
+
+  // Wait for all database connections to close.
+  request = reset();
+  await requestFinished(request);
+
+  exportShadowDatabase("shadowdb-clearedOrigin.sqlite");
+
+  // The shadow database is now prepared for
+  // test_databaseShadowing_clearOrigin2.js
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin2.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin2.js
new file mode 100644
index 0000000000..83d792b496
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOrigin2.js
@@ -0,0 +1,17 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  // The shadow database was prepared in test_databaseShadowing_clearOrigin1.js
+
+  disableNextGenLocalStorage();
+
+  ok(importShadowDatabase("shadowdb-clearedOrigin.sqlite"), "Import succeeded");
+
+  verifyData([1], /* migrated */ true);
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern1.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern1.js
new file mode 100644
index 0000000000..70367bbeff
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern1.js
@@ -0,0 +1,29 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  enableNextGenLocalStorage();
+
+  storeData();
+
+  verifyData([]);
+
+  let request = clearOriginsByPattern(JSON.stringify({ userContextId: 15 }));
+  await requestFinished(request);
+
+  verifyData([4, 5, 6]);
+
+  // Wait for all database connections to close.
+  request = reset();
+  await requestFinished(request);
+
+  exportShadowDatabase("shadowdb-clearedOriginsByPattern.sqlite");
+
+  // The shadow database is now prepared for
+  // test_databaseShadowing_clearOriginsByPattern2.js
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern2.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern2.js
new file mode 100644
index 0000000000..6c4d794d04
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPattern2.js
@@ -0,0 +1,21 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  // The shadow database was prepared in
+  // test_databaseShadowing_clearOriginsByPattern1.js
+
+  disableNextGenLocalStorage();
+
+  ok(
+    importShadowDatabase("shadowdb-clearedOriginsByPattern.sqlite"),
+    "Import succeeded"
+  );
+
+  verifyData([4, 5, 6], /* migrated */ true);
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix1.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix1.js
new file mode 100644
index 0000000000..2b605e953f
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix1.js
@@ -0,0 +1,28 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  enableNextGenLocalStorage();
+
+  storeData();
+
+  verifyData([]);
+
+  let principal = getPrincipal("http://prefix.test", {});
+  let request = clearOriginsByPrefix(principal, "default");
+  await requestFinished(request);
+
+  // Wait for all database connections to close.
+  request = reset();
+  await requestFinished(request);
+
+  exportShadowDatabase("shadowdb-clearedOriginsByPrefix.sqlite");
+
+  // The shadow database is now prepared for
+  // test_databaseShadowing_clearOriginsByPrefix2.js
+});
diff --git a/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix2.js b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix2.js
new file mode 100644
index 0000000000..892a470723
--- /dev/null
+++ b/dom/localstorage/test/unit/test_databaseShadowing_clearOriginsByPrefix2.js
@@ -0,0 +1,21 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* import-globals-from databaseShadowing-shared.js */
+loadSubscript("databaseShadowing-shared.js");
+
+add_task(async function testSteps() {
+  // The shadow database was prepared in
+  // test_databaseShadowing_clearOriginsByPrefix1.js
+
+  disableNextGenLocalStorage();
+
+  ok(
+    importShadowDatabase("shadowdb-clearedOriginsByPrefix.sqlite"),
+    "Import succeeded"
+  );
+
+  verifyData([2, 3], /* migrated */ true);
+});
diff --git a/dom/localstorage/test/unit/test_eviction.js b/dom/localstorage/test/unit/test_eviction.js
new file mode 100644
index 0000000000..d8c10b771f
--- /dev/null
+++ b/dom/localstorage/test/unit/test_eviction.js
@@ -0,0 +1,91 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const globalLimitKB = 5 * 1024;
+
+  const data = {};
+  data.sizeKB = 1 * 1024;
+  data.key = "A";
+  data.value = repeatChar(data.sizeKB * 1024 - data.key.length, ".");
+  data.urlCount = globalLimitKB / data.sizeKB;
+
+  function getSpec(index) {
+    return "http://example" + index + ".com";
+  }
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  info("Setting limits");
+
+  setGlobalLimit(globalLimitKB);
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Getting storages");
+
+  let storages = [];
+  for (let i = 0; i < data.urlCount; i++) {
+    let storage = getLocalStorage(getPrincipal(getSpec(i)));
+    storages.push(storage);
+  }
+
+  info("Filling up entire default storage");
+
+  for (let i = 0; i < data.urlCount; i++) {
+    storages[i].setItem(data.key, data.value);
+    await returnToEventLoop();
+  }
+
+  info("Verifying no more data can be written");
+
+  for (let i = 0; i < data.urlCount; i++) {
+    try {
+      storages[i].setItem("B", "");
+      ok(false, "Should have thrown");
+    } catch (ex) {
+      ok(true, "Did throw");
+      ok(DOMException.isInstance(ex), "Threw DOMException");
+      is(ex.name, "QuotaExceededError", "Threw right DOMException");
+      is(ex.code, NS_ERROR_DOM_QUOTA_EXCEEDED_ERR, "Threw with right code");
+    }
+  }
+
+  info("Closing first origin");
+
+  storages[0].close();
+
+  let principal = getPrincipal("http://example0.com");
+
+  request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage for first origin");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, data.sizeKB * 1024, "Correct usage");
+
+  info("Verifying more data data can be written");
+
+  for (let i = 1; i < data.urlCount; i++) {
+    storages[i].setItem("B", "");
+  }
+
+  info("Getting usage for first origin");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, 0, "Zero usage");
+});
diff --git a/dom/localstorage/test/unit/test_flushing.js b/dom/localstorage/test/unit/test_flushing.js
new file mode 100644
index 0000000000..17f015d5ef
--- /dev/null
+++ b/dom/localstorage/test/unit/test_flushing.js
@@ -0,0 +1,72 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+
+/**
+ * This test is mainly to verify that the flush operation detaches the shadow
+ * database in the event of early return due to error. See bug 1559029.
+ */
+
+add_task(async function testSteps() {
+  const principal1 = getPrincipal("http://example1.com");
+
+  const usageFile1 = getRelativeFile(
+    "storage/default/http+++example1.com/ls/usage"
+  );
+
+  const principal2 = getPrincipal("http://example2.com");
+
+  const data = {
+    key: "foo",
+    value: "bar",
+  };
+
+  const flushSleepTimeSec = 6;
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", true);
+
+  info("Getting storage 1");
+
+  let storage1 = getLocalStorage(principal1);
+
+  info("Adding item");
+
+  storage1.setItem(data.key, data.value);
+
+  info("Creating usage as a directory");
+
+  // This will cause a failure during the flush for first principal.
+  usageFile1.create(Ci.nsIFile.DIRECTORY_TYPE, parseInt("0755", 8));
+
+  info("Getting storage 2");
+
+  let storage2 = getLocalStorage(principal2);
+
+  info("Adding item");
+
+  storage2.setItem(data.key, data.value);
+
+  // The flush for second principal shouldn't be affected by failed flush for
+  // first principal.
+
+  info(
+    "Sleeping for " +
+      flushSleepTimeSec +
+      " seconds to let all flushes " +
+      "finish"
+  );
+
+  await new Promise(function (resolve) {
+    setTimeout(resolve, flushSleepTimeSec * 1000);
+  });
+
+  info("Resetting");
+
+  // Wait for all database connections to close.
+  let request = reset();
+  await requestFinished(request);
+});
diff --git a/dom/localstorage/test/unit/test_groupLimit.js b/dom/localstorage/test/unit/test_groupLimit.js
new file mode 100644
index 0000000000..92ff07b7ab
--- /dev/null
+++ b/dom/localstorage/test/unit/test_groupLimit.js
@@ -0,0 +1,85 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const groupLimitKB = 10 * 1024;
+
+  const globalLimitKB = groupLimitKB * 5;
+
+  const originLimit = 10 * 1024;
+
+  const urls = [
+    "http://example.com",
+    "http://test1.example.com",
+    "https://test2.example.com",
+    "http://test3.example.com:8080",
+  ];
+
+  const data = {};
+  data.sizeKB = 5 * 1024;
+  data.key = "A";
+  data.value = repeatChar(data.sizeKB * 1024 - data.key.length, ".");
+  data.urlCount = groupLimitKB / data.sizeKB;
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  info("Setting limits");
+
+  setGlobalLimit(globalLimitKB);
+
+  let request = clear();
+  await requestFinished(request);
+
+  setOriginLimit(originLimit);
+
+  info("Getting storages");
+
+  let storages = [];
+  for (let i = 0; i < urls.length; i++) {
+    let storage = getLocalStorage(getPrincipal(urls[i]));
+    storages.push(storage);
+  }
+
+  info("Filling up the whole group");
+
+  for (let i = 0; i < data.urlCount; i++) {
+    storages[i].setItem(data.key, data.value);
+    await returnToEventLoop();
+  }
+
+  info("Verifying no more data can be written");
+
+  for (let i = 0; i < urls.length; i++) {
+    try {
+      storages[i].setItem("B", "");
+      ok(false, "Should have thrown");
+    } catch (ex) {
+      ok(true, "Did throw");
+      ok(DOMException.isInstance(ex), "Threw DOMException");
+      is(ex.name, "QuotaExceededError", "Threw right DOMException");
+      is(ex.code, NS_ERROR_DOM_QUOTA_EXCEEDED_ERR, "Threw with right code");
+    }
+  }
+
+  info("Clearing first origin");
+
+  storages[0].clear();
+
+  // Let the internal snapshot finish (usage is not descreased until all
+  // snapshots finish)..
+  await returnToEventLoop();
+
+  info("Verifying more data can be written");
+
+  for (let i = 0; i < urls.length; i++) {
+    storages[i].setItem("B", "");
+  }
+});
diff --git a/dom/localstorage/test/unit/test_groupMismatch.js b/dom/localstorage/test/unit/test_groupMismatch.js
new file mode 100644
index 0000000000..46533aa2f7
--- /dev/null
+++ b/dom/localstorage/test/unit/test_groupMismatch.js
@@ -0,0 +1,45 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test is mainly to verify that metadata files with old group information
+ * get updated, so writing to local storage won't cause a crash because of null
+ * quota object. See bug 1516333.
+ */
+
+add_task(async function testSteps() {
+  const principal = getPrincipal("https://foo.bar.mozilla-iot.org");
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains one initialized origin directory, a script for origin
+  // initialization and the storage database:
+  // - storage/default/https+++foo.bar.mozilla-iot.org
+  // - create_db.js
+  // - storage.sqlite
+  // The file create_db.js in the package was run locally, specifically it was
+  // temporarily added to xpcshell.ini and then executed:
+  //   mach xpcshell-test --interactive dom/localstorage/test/unit/create_db.js
+  // Note: to make it become the profile in the test, additional manual steps
+  // are needed.
+  // 1. Manually change the group in .metadata and .metadata-v2 from
+  //    "bar.mozilla-iot.org" to "mozilla-iot.org".
+  // 2. Remove the folder "storage/temporary".
+  // 3. Remove the file "storage/ls-archive.sqlite".
+  installPackage("groupMismatch_profile");
+
+  info("Getting storage");
+
+  let storage = getLocalStorage(principal);
+
+  info("Adding item");
+
+  storage.setItem("foo", "bar");
+});
diff --git a/dom/localstorage/test/unit/test_largeItems.js b/dom/localstorage/test/unit/test_largeItems.js
new file mode 100644
index 0000000000..3ea6bd21b4
--- /dev/null
+++ b/dom/localstorage/test/unit/test_largeItems.js
@@ -0,0 +1,88 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * Test repeatedly setting values that are just under the LocalStorage quota
+ * limit without yielding control flow in order to verify that the write
+ * optimizer is present / works. If there was no write optimizer present, the
+ * IPC message size limit would be exceeded, resulting in a crash.
+ */
+
+add_task(async function testSteps() {
+  const globalLimitKB = 5 * 1024;
+
+  // 18 and more iterations would produce an IPC message with size greater than
+  // 256 MB if write optimizer was not present. This number was determined
+  // experimentally by running the test with disabled write optimizer.
+  const numberOfIterations = 18;
+
+  const randomStringBlockSize = 65536;
+
+  // We need to use a random string because LS internally tries to compress
+  // values.
+  function getRandomString(size) {
+    let crypto = this.window ? this.window.crypto : this.crypto;
+    let decoder = new TextDecoder("ISO-8859-2");
+
+    function getRandomStringBlock(array) {
+      crypto.getRandomValues(array);
+      return decoder.decode(array);
+    }
+
+    let string = "";
+
+    let quotient = size / randomStringBlockSize;
+    if (quotient) {
+      let array = new Uint8Array(randomStringBlockSize);
+      for (let i = 1; i <= quotient; i++) {
+        string += getRandomStringBlock(array);
+      }
+    }
+
+    let remainder = size % randomStringBlockSize;
+    if (remainder) {
+      let array = new Uint8Array(remainder);
+      string += getRandomStringBlock(array);
+    }
+
+    return string;
+  }
+
+  const data = {};
+  data.key = "foo";
+  data.value = getRandomString(
+    globalLimitKB * 1024 -
+      data.key.length -
+      numberOfIterations.toString().length
+  );
+
+  info("Setting pref");
+
+  // By disabling snapshot reusing, we guarantee that the snapshot will be
+  // checkpointed once control returns to the event loop.
+  if (this.window) {
+    await SpecialPowers.pushPrefEnv({
+      set: [["dom.storage.snapshot_reusing", false]],
+    });
+  } else {
+    Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+  }
+
+  info("Getting storage");
+
+  let storage = getLocalStorage();
+
+  info("Adding/updating item");
+
+  for (var i = 0; i < numberOfIterations; i++) {
+    storage.setItem(data.key, data.value + i);
+  }
+
+  info("Returning to event loop");
+
+  await returnToEventLoop();
+
+  ok(!storage.hasSnapshot, "Snapshot successfully finished");
+});
diff --git a/dom/localstorage/test/unit/test_lsng_enabled.js b/dom/localstorage/test/unit/test_lsng_enabled.js
new file mode 100644
index 0000000000..d978aaa901
--- /dev/null
+++ b/dom/localstorage/test/unit/test_lsng_enabled.js
@@ -0,0 +1,13 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test is mainly to verify that LSNG is not accidentally disabled which
+ * can lead to a data loss in a combination with disabled shadow writes.
+ */
+
+add_task(async function testSteps() {
+  ok(Services.domStorageManager.nextGenLocalStorageEnabled, "LSNG enabled");
+});
diff --git a/dom/localstorage/test/unit/test_migration.js b/dom/localstorage/test/unit/test_migration.js
new file mode 100644
index 0000000000..1249eb076f
--- /dev/null
+++ b/dom/localstorage/test/unit/test_migration.js
@@ -0,0 +1,127 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const principalInfos = [
+    { url: "http://localhost", attrs: {} },
+    { url: "http://www.mozilla.org", attrs: {} },
+    { url: "http://example.com", attrs: {} },
+    { url: "http://example.org", attrs: { userContextId: 5 } },
+
+    { url: "http://origin.test", attrs: {} },
+
+    { url: "http://prefix.test", attrs: {} },
+    { url: "http://prefix.test", attrs: { userContextId: 10 } },
+
+    { url: "http://pattern.test", attrs: { userContextId: 15 } },
+    { url: "http://pattern.test:8080", attrs: { userContextId: 15 } },
+    { url: "https://pattern.test", attrs: { userContextId: 15 } },
+  ];
+
+  const data = {
+    key: "foo",
+    value: "bar",
+  };
+
+  function verifyData(clearedOrigins) {
+    info("Getting storages");
+
+    let storages = [];
+    for (let i = 0; i < principalInfos.length; i++) {
+      let principalInfo = principalInfos[i];
+      let principal = getPrincipal(principalInfo.url, principalInfo.attrs);
+      let storage = getLocalStorage(principal);
+      storages.push(storage);
+    }
+
+    info("Verifying data");
+
+    for (let i = 0; i < storages.length; i++) {
+      let value = storages[i].getItem(data.key + i);
+      if (clearedOrigins.includes(i)) {
+        is(value, null, "Correct value");
+      } else {
+        is(value, data.value + i, "Correct value");
+      }
+    }
+  }
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Testing archived data migration");
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains storage.sqlite and webappsstore.sqlite. The file
+  // create_db.js in the package was run locally, specifically it was
+  // temporarily added to xpcshell.ini and then executed:
+  // mach xpcshell-test --interactive dom/localstorage/test/unit/create_db.js
+  installPackage("migration_profile");
+
+  verifyData([]);
+
+  info("Stage 2 - Testing archived data clearing");
+
+  for (let type of ["origin", "prefix", "pattern"]) {
+    info("Clearing");
+
+    request = clear();
+    await requestFinished(request);
+
+    info("Installing package");
+
+    // See the comment for the first installPackage() call.
+    installPackage("migration_profile");
+
+    let clearedOrigins = [];
+
+    switch (type) {
+      case "origin": {
+        let principal = getPrincipal("http://origin.test", {});
+        request = clearOrigin(principal, "default");
+        await requestFinished(request);
+
+        clearedOrigins.push(4);
+
+        break;
+      }
+
+      case "prefix": {
+        let principal = getPrincipal("http://prefix.test", {});
+        request = clearOriginsByPrefix(principal, "default");
+        await requestFinished(request);
+
+        clearedOrigins.push(5, 6);
+
+        break;
+      }
+
+      case "pattern": {
+        request = clearOriginsByPattern(JSON.stringify({ userContextId: 15 }));
+        await requestFinished(request);
+
+        clearedOrigins.push(7, 8, 9);
+
+        break;
+      }
+
+      default: {
+        throw new Error("Unknown type: " + type);
+      }
+    }
+
+    verifyData(clearedOrigins);
+  }
+});
diff --git a/dom/localstorage/test/unit/test_migration_emptyValue.js b/dom/localstorage/test/unit/test_migration_emptyValue.js
new file mode 100644
index 0000000000..dd09c82e88
--- /dev/null
+++ b/dom/localstorage/test/unit/test_migration_emptyValue.js
@@ -0,0 +1,37 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const data = {
+    key: "foo",
+    value: "",
+  };
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains storage.sqlite and webappsstore.sqlite.
+  // The archive migration_emptyValue_profile.zip was created by running
+  // make_migration_emptyValue.js locally, specifically the special test was
+  // temporarily activated in xpcshell.ini and then it was run as:
+  // mach test --interactive dom/localstorage/test/unit/make_migration_emptyValue.js
+  // Before packaging, additional manual steps are needed:
+  // 1. Folder "cache2" is removed.
+  // 2. Folder "crashes" is removed.
+  // 3. File "mozinfo.json" is removed.
+  installPackage("migration_emptyValue_profile");
+
+  info("Getting storage");
+
+  const storage = getLocalStorage();
+
+  info("Verifying data");
+
+  is(storage.getItem(data.key), data.value, "Correct value");
+});
diff --git a/dom/localstorage/test/unit/test_old_lsng_pref.js b/dom/localstorage/test/unit/test_old_lsng_pref.js
new file mode 100644
index 0000000000..d502ee8779
--- /dev/null
+++ b/dom/localstorage/test/unit/test_old_lsng_pref.js
@@ -0,0 +1,17 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test is mainly to verify that the old pref for switching LS
+ * implementations has no effect anymore.
+ */
+
+add_task(async function testSteps() {
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", false);
+
+  ok(Services.domStorageManager.nextGenLocalStorageEnabled, "LSNG enabled");
+});
diff --git a/dom/localstorage/test/unit/test_orderingAfterRemoveAdd.js b/dom/localstorage/test/unit/test_orderingAfterRemoveAdd.js
new file mode 100644
index 0000000000..88a2e45d2a
--- /dev/null
+++ b/dom/localstorage/test/unit/test_orderingAfterRemoveAdd.js
@@ -0,0 +1,70 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const url = "http://example.com";
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  const items = [
+    { key: "key01", value: "value01" },
+    { key: "key02", value: "value02" },
+    { key: "key03", value: "value03" },
+    { key: "key04", value: "value04" },
+    { key: "key05", value: "value05" },
+  ];
+
+  info("Getting storage");
+
+  let storage = getLocalStorage(getPrincipal(url));
+
+  // 1st snapshot
+
+  info("Adding data");
+
+  for (let item of items) {
+    storage.setItem(item.key, item.value);
+  }
+
+  info("Returning to event loop");
+
+  await returnToEventLoop();
+
+  // 2nd snapshot
+
+  // Remove first two items, add some new items and add the two items back.
+
+  storage.removeItem("key01");
+  storage.removeItem("key02");
+
+  storage.setItem("key06", "value06");
+  storage.setItem("key07", "value07");
+  storage.setItem("key08", "value08");
+
+  storage.setItem("key01", "value01");
+  storage.setItem("key02", "value02");
+
+  info("Saving key order");
+
+  let savedKeys = Object.keys(storage);
+
+  info("Returning to event loop");
+
+  await returnToEventLoop();
+
+  // 3rd snapshot
+
+  info("Verifying key order");
+
+  let keys = Object.keys(storage);
+
+  is(keys.length, savedKeys.length);
+
+  for (let i = 0; i < keys.length; i++) {
+    is(keys[i], savedKeys[i], "Correct key");
+  }
+});
diff --git a/dom/localstorage/test/unit/test_originInit.js b/dom/localstorage/test/unit/test_originInit.js
new file mode 100644
index 0000000000..71ad0fbf40
--- /dev/null
+++ b/dom/localstorage/test/unit/test_originInit.js
@@ -0,0 +1,372 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const storageDirName = "storage";
+  const persistenceTypeDefaultDirName = "default";
+  const persistenceTypePersistentDirName = "permanent";
+
+  const principal = getPrincipal("http://example.com");
+
+  const originDirName = "http+++example.com";
+
+  const clientLSDirName = "ls";
+
+  const dataFile = getRelativeFile(
+    `${storageDirName}/${persistenceTypeDefaultDirName}/${originDirName}/` +
+      `${clientLSDirName}/data.sqlite`
+  );
+
+  const usageJournalFile = getRelativeFile(
+    `${storageDirName}/${persistenceTypeDefaultDirName}/${originDirName}/` +
+      `${clientLSDirName}/usage-journal`
+  );
+
+  const usageFile = getRelativeFile(
+    `${storageDirName}/${persistenceTypeDefaultDirName}/${originDirName}/` +
+      `${clientLSDirName}/usage`
+  );
+
+  const persistentLSDir = getRelativeFile(
+    `${storageDirName}/${persistenceTypePersistentDirName}/${originDirName}/` +
+      `${clientLSDirName}`
+  );
+
+  const data = {};
+  data.key = "key1";
+  data.value = "value1";
+  data.usage = data.key.length + data.value.length;
+
+  const usageFileCookie = 0x420a420a;
+
+  async function createTestOrigin() {
+    let storage = getLocalStorage(principal);
+
+    storage.setItem(data.key, data.value);
+
+    let request = reset();
+    await requestFinished(request);
+  }
+
+  async function createPersistentTestOrigin() {
+    let database = getSimpleDatabase(principal, "persistent");
+
+    let request = database.open("data");
+    await requestFinished(request);
+
+    request = reset();
+    await requestFinished(request);
+  }
+
+  function removeFile(file) {
+    file.remove(false);
+  }
+
+  function createEmptyFile(file) {
+    file.create(Ci.nsIFile.NORMAL_FILE_TYPE, 0o0644);
+  }
+
+  function createEmptyDirectory(dir) {
+    dir.create(Ci.nsIFile.DIRECTORY_TYPE, 0o0755);
+  }
+
+  function getBinaryOutputStream(file) {
+    var ostream = Cc[
+      "@mozilla.org/network/file-output-stream;1"
+    ].createInstance(Ci.nsIFileOutputStream);
+    ostream.init(file, -1, parseInt("0644", 8), 0);
+
+    let bstream = Cc["@mozilla.org/binaryoutputstream;1"].createInstance(
+      Ci.nsIBinaryOutputStream
+    );
+    bstream.setOutputStream(ostream);
+
+    return bstream;
+  }
+
+  async function initTestOrigin() {
+    let request = initStorage();
+    await requestFinished(request);
+
+    request = initTemporaryStorage();
+    await requestFinished(request);
+
+    request = initTemporaryOrigin("default", principal);
+    await requestFinished(request);
+  }
+
+  async function initPersistentTestOrigin() {
+    let request = initStorage();
+    await requestFinished(request);
+
+    request = initPersistentOrigin(principal);
+    await requestFinished(request);
+  }
+
+  async function checkFiles(wantData, wantUsage) {
+    let exists = dataFile.exists();
+    if (wantData) {
+      ok(exists, "Data file does exist");
+    } else {
+      ok(!exists, "Data file doesn't exist");
+    }
+
+    exists = usageJournalFile.exists();
+    ok(!exists, "Usage journal file doesn't exist");
+
+    exists = usageFile.exists();
+    if (wantUsage) {
+      ok(exists, "Usage file does exist");
+    } else {
+      ok(!exists, "Usage file doesn't exist");
+      return;
+    }
+
+    let usage = await readUsageFromUsageFile(usageFile);
+    Assert.equal(usage, data.usage, "Correct usage");
+  }
+
+  async function clearTestOrigin() {
+    let request = clearOrigin(principal, "default");
+    await requestFinished(request);
+  }
+
+  async function clearPersistentTestOrigin() {
+    let request = clearOrigin(principal, "persistent");
+    await requestFinished(request);
+  }
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info(
+    "Stage 1 - " +
+      "data.sqlite file doesn't exist, " +
+      "usage-journal file doesn't exist, " +
+      "any usage file exists"
+  );
+
+  await createTestOrigin();
+
+  removeFile(dataFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ false, /* wantUsage */ false);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 2 - " +
+      "data.sqlite file doesn't exist, " +
+      "any usage-journal file exists, " +
+      "any usage file exists"
+  );
+
+  await createTestOrigin();
+
+  removeFile(dataFile);
+  createEmptyFile(usageJournalFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ false, /* wantUsage */ false);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 3 - " +
+      "valid data.sqlite file exists, " +
+      "usage-journal file doesn't exist, " +
+      "usage file doesn't exist"
+  );
+
+  await createTestOrigin();
+
+  removeFile(usageFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 4 - " +
+      "valid data.sqlite file exists, " +
+      "usage-journal file doesn't exist, " +
+      "invalid (wrong file size) usage file exists"
+  );
+
+  await createTestOrigin();
+
+  removeFile(usageFile);
+  createEmptyFile(usageFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 5 - " +
+      "valid data.sqlite file exists, " +
+      "usage-journal file doesn't exist, " +
+      "invalid (wrong cookie) usage file exists"
+  );
+
+  await createTestOrigin();
+
+  let stream = getBinaryOutputStream(usageFile);
+  stream.write32(usageFileCookie - 1);
+  stream.write64(data.usage);
+  stream.close();
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 6 - " +
+      "valid data.sqlite file exists, " +
+      "usage-journal file doesn't exist, " +
+      "valid usage file exists"
+  );
+
+  await createTestOrigin();
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 7 - " +
+      "valid data.sqlite file exists, " +
+      "any usage-journal exists, " +
+      "usage file doesn't exist"
+  );
+
+  await createTestOrigin();
+
+  createEmptyFile(usageJournalFile);
+  removeFile(usageFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 8 - " +
+      "valid data.sqlite file exists, " +
+      "any usage-journal exists, " +
+      "invalid (wrong file size) usage file exists"
+  );
+
+  await createTestOrigin();
+
+  createEmptyFile(usageJournalFile);
+  removeFile(usageFile);
+  createEmptyFile(usageFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 9 - " +
+      "valid data.sqlite file exists, " +
+      "any usage-journal exists, " +
+      "invalid (wrong cookie) usage file exists"
+  );
+
+  await createTestOrigin();
+
+  createEmptyFile(usageJournalFile);
+  stream = getBinaryOutputStream(usageFile);
+  stream.write32(usageFileCookie - 1);
+  stream.write64(data.usage);
+  stream.close();
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 10 - " +
+      "valid data.sqlite file exists, " +
+      "any usage-journal exists, " +
+      "invalid (wrong usage) usage file exists"
+  );
+
+  await createTestOrigin();
+
+  createEmptyFile(usageJournalFile);
+  stream = getBinaryOutputStream(usageFile);
+  stream.write32(usageFileCookie);
+  stream.write64(data.usage - 1);
+  stream.close();
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  info(
+    "Stage 11 - " +
+      "valid data.sqlite file exists, " +
+      "any usage-journal exists, " +
+      "valid usage file exists"
+  );
+
+  await createTestOrigin();
+
+  createEmptyFile(usageJournalFile);
+
+  await initTestOrigin();
+
+  await checkFiles(/* wantData */ true, /* wantUsage */ true);
+
+  await clearTestOrigin();
+
+  // Verify that InitializeOrigin doesn't fail when a
+  // storage/permanent/${origin}/ls exists.
+  info(
+    "Stage 12 - Testing initialization of ls directory placed in permanent " +
+      "origin directory"
+  );
+
+  await createPersistentTestOrigin();
+
+  createEmptyDirectory(persistentLSDir);
+
+  try {
+    await initPersistentTestOrigin();
+
+    ok(true, "Should not have thrown");
+  } catch (ex) {
+    ok(false, "Should not have thrown");
+  }
+
+  let exists = persistentLSDir.exists();
+  ok(exists, "ls directory in permanent origin directory does exist");
+
+  await clearPersistentTestOrigin();
+});
diff --git a/dom/localstorage/test/unit/test_preloading.js b/dom/localstorage/test/unit/test_preloading.js
new file mode 100644
index 0000000000..c3b7c808eb
--- /dev/null
+++ b/dom/localstorage/test/unit/test_preloading.js
@@ -0,0 +1,87 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const principals = [
+    getPrincipal("http://example.com", {}),
+    getPrincipal("http://example.com", { privateBrowsingId: 1 }),
+  ];
+
+  async function isPreloaded(principal) {
+    return Services.domStorageManager.isPreloaded(principal);
+  }
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  for (const principal of principals) {
+    info("Getting storage");
+
+    let storage = getLocalStorage(principal);
+
+    ok(
+      !(await isPreloaded(principal)),
+      "Data is not preloaded after getting storage"
+    );
+
+    info("Opening storage");
+
+    storage.open();
+
+    ok(await isPreloaded(principal), "Data is preloaded after opening storage");
+
+    info("Closing storage");
+
+    storage.close();
+
+    if (principal.privateBrowsingId > 0) {
+      ok(
+        await isPreloaded(principal),
+        "Data is still preloaded after closing storage"
+      );
+
+      info("Closing private session");
+
+      Services.obs.notifyObservers(null, "last-pb-context-exited");
+
+      ok(
+        !(await isPreloaded(principal)),
+        "Data is not preloaded anymore after closing private session"
+      );
+    } else {
+      ok(
+        !(await isPreloaded(principal)),
+        "Data is not preloaded anymore after closing storage"
+      );
+    }
+
+    info("Opening storage again");
+
+    storage.open();
+
+    ok(
+      await isPreloaded(principal),
+      "Data is preloaded after opening storage again"
+    );
+
+    info("Clearing origin");
+
+    let request = clearOrigin(
+      principal,
+      principal.privateBrowsingId > 0 ? "private" : "default"
+    );
+    await requestFinished(request);
+
+    ok(
+      !(await isPreloaded(principal)),
+      "Data is not preloaded after clearing origin"
+    );
+  }
+});
diff --git a/dom/localstorage/test/unit/test_schema3upgrade.js b/dom/localstorage/test/unit/test_schema3upgrade.js
new file mode 100644
index 0000000000..4b851642ea
--- /dev/null
+++ b/dom/localstorage/test/unit/test_schema3upgrade.js
@@ -0,0 +1,39 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const url = "http://example.com";
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", true);
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains one initialized origin directory with local
+  // storage data, local storage archive, a script for origin initialization,
+  // the storage database and the web apps store database:
+  // - storage/default/http+++example.com
+  // - storage/ls-archive.sqlite
+  // - create_db.js
+  // - storage.sqlite
+  // - webappsstore.sqlite
+  // The file create_db.js in the package was run locally (with a build with
+  // local storage archive version 1 and database schema version 2),
+  // specifically it was temporarily added to xpcshell.ini and then executed:
+  //   mach xpcshell-test --interactive dom/localstorage/test/unit/create_db.js
+  // Note: to make it become the profile in the test, additional manual steps
+  // are needed.
+  // 1. Remove the folder "storage/temporary".
+  installPackage("schema3upgrade_profile");
+
+  let storage = getLocalStorage(getPrincipal(url));
+  storage.open();
+});
diff --git a/dom/localstorage/test/unit/test_schema4upgrade.js b/dom/localstorage/test/unit/test_schema4upgrade.js
new file mode 100644
index 0000000000..a6c308af35
--- /dev/null
+++ b/dom/localstorage/test/unit/test_schema4upgrade.js
@@ -0,0 +1,39 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const url = "http://example.com";
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.next_gen", true);
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains one initialized origin directory with local
+  // storage data, local storage archive, a script for origin initialization,
+  // the storage database and the web apps store database:
+  // - storage/default/http+++example.com
+  // - storage/ls-archive.sqlite
+  // - storage.sqlite
+  // - test_create_db.js
+  // - webappsstore.sqlite
+  //
+  // The file test_create_db.js in the package was run locally by
+  // adding it temporarily to xpcshell.ini and then executed with
+  //   mach xpcshell-test --headless dom/localstorage/test/unit/test_create_db.js
+  // Note: to make it become the profile in the test, additional manual steps
+  // are needed.
+  // 1. Remove the folder "storage/temporary".
+  installPackage("schema4upgrade_profile");
+
+  let storage = getLocalStorage(getPrincipal(url));
+  storage.open();
+});
diff --git a/dom/localstorage/test/unit/test_snapshotting.js b/dom/localstorage/test/unit/test_snapshotting.js
new file mode 100644
index 0000000000..4b639395f7
--- /dev/null
+++ b/dom/localstorage/test/unit/test_snapshotting.js
@@ -0,0 +1,330 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const url = "http://example.com";
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  const items = [
+    { key: "key01", value: "value01" },
+    { key: "key02", value: "value02" },
+    { key: "key03", value: "value03" },
+    { key: "key04", value: "value04" },
+    { key: "key05", value: "value05" },
+    { key: "key06", value: "value06" },
+    { key: "key07", value: "value07" },
+    { key: "key08", value: "value08" },
+    { key: "key09", value: "value09" },
+    { key: "key10", value: "value10" },
+  ];
+
+  let sizeOfOneKey;
+  let sizeOfOneValue;
+  let sizeOfOneItem;
+  let sizeOfKeys = 0;
+  let sizeOfItems = 0;
+
+  for (let i = 0; i < items.length; i++) {
+    let item = items[i];
+    let sizeOfKey = item.key.length;
+    let sizeOfValue = item.value.length;
+    let sizeOfItem = sizeOfKey + sizeOfValue;
+    if (i == 0) {
+      sizeOfOneKey = sizeOfKey;
+      sizeOfOneValue = sizeOfValue;
+      sizeOfOneItem = sizeOfItem;
+    }
+    sizeOfKeys += sizeOfKey;
+    sizeOfItems += sizeOfItem;
+  }
+
+  info("Size of one key is " + sizeOfOneKey);
+  info("Size of one value is " + sizeOfOneValue);
+  info("Size of one item is " + sizeOfOneItem);
+  info("Size of keys is " + sizeOfKeys);
+  info("Size of items is " + sizeOfItems);
+
+  const prefillValues = [
+    // Zero prefill (prefill disabled)
+    0,
+    // Less than one key length prefill
+    sizeOfOneKey - 1,
+    // Greater than one key length and less than one item length prefill
+    sizeOfOneKey + 1,
+    // Precisely one item length prefill
+    sizeOfOneItem,
+    // Precisely two times one item length prefill
+    2 * sizeOfOneItem,
+    // Precisely three times one item length prefill
+    3 * sizeOfOneItem,
+    // Precisely four times one item length prefill
+    4 * sizeOfOneItem,
+    // Precisely size of keys prefill
+    sizeOfKeys,
+    // Less than size of keys plus one value length prefill
+    sizeOfKeys + sizeOfOneValue - 1,
+    // Precisely size of keys plus one value length prefill
+    sizeOfKeys + sizeOfOneValue,
+    // Greater than size of keys plus one value length and less than size of
+    // keys plus two times one value length prefill
+    sizeOfKeys + sizeOfOneValue + 1,
+    // Precisely size of keys plus two times one value length prefill
+    sizeOfKeys + 2 * sizeOfOneValue,
+    // Precisely size of keys plus three times one value length prefill
+    sizeOfKeys + 3 * sizeOfOneValue,
+    // Precisely size of keys plus four times one value length prefill
+    sizeOfKeys + 4 * sizeOfOneValue,
+    // Precisely size of keys plus five times one value length prefill
+    sizeOfKeys + 5 * sizeOfOneValue,
+    // Precisely size of keys plus six times one value length prefill
+    sizeOfKeys + 6 * sizeOfOneValue,
+    // Precisely size of keys plus seven times one value length prefill
+    sizeOfKeys + 7 * sizeOfOneValue,
+    // Precisely size of keys plus eight times one value length prefill
+    sizeOfKeys + 8 * sizeOfOneValue,
+    // Precisely size of keys plus nine times one value length prefill
+    sizeOfKeys + 9 * sizeOfOneValue,
+    // Precisely size of items prefill
+    sizeOfItems,
+    // Unlimited prefill
+    -1,
+  ];
+
+  for (let prefillValue of prefillValues) {
+    info("Setting prefill value to " + prefillValue);
+
+    Services.prefs.setIntPref("dom.storage.snapshot_prefill", prefillValue);
+
+    const gradualPrefillValues = [
+      // Zero gradual prefill
+      0,
+      // Less than one key length gradual prefill
+      sizeOfOneKey - 1,
+      // Greater than one key length and less than one item length gradual
+      // prefill
+      sizeOfOneKey + 1,
+      // Precisely one item length gradual prefill
+      sizeOfOneItem,
+      // Precisely two times one item length gradual prefill
+      2 * sizeOfOneItem,
+      // Precisely three times one item length gradual prefill
+      3 * sizeOfOneItem,
+      // Precisely four times one item length gradual prefill
+      4 * sizeOfOneItem,
+      // Precisely five times one item length gradual prefill
+      5 * sizeOfOneItem,
+      // Precisely six times one item length gradual prefill
+      6 * sizeOfOneItem,
+      // Precisely seven times one item length gradual prefill
+      7 * sizeOfOneItem,
+      // Precisely eight times one item length gradual prefill
+      8 * sizeOfOneItem,
+      // Precisely nine times one item length gradual prefill
+      9 * sizeOfOneItem,
+      // Precisely size of items prefill
+      sizeOfItems,
+      // Unlimited gradual prefill
+      -1,
+    ];
+
+    for (let gradualPrefillValue of gradualPrefillValues) {
+      info("Setting gradual prefill value to " + gradualPrefillValue);
+
+      Services.prefs.setIntPref(
+        "dom.storage.snapshot_gradual_prefill",
+        gradualPrefillValue
+      );
+
+      info("Getting storage");
+
+      let storage = getLocalStorage(getPrincipal(url));
+
+      // 1st snapshot
+
+      info("Adding data");
+
+      for (let item of items) {
+        storage.setItem(item.key, item.value);
+      }
+
+      info("Saving key order");
+
+      // This forces GetKeys to be called internally.
+      let savedKeys = Object.keys(storage);
+
+      // GetKey should match GetKeys
+      for (let i = 0; i < savedKeys.length; i++) {
+        is(storage.key(i), savedKeys[i], "Correct key");
+      }
+
+      info("Returning to event loop");
+
+      // Returning to event loop forces the internal snapshot to finish.
+      await returnToEventLoop();
+
+      // 2nd snapshot
+
+      info("Verifying length");
+
+      is(storage.length, items.length, "Correct length");
+
+      info("Verifying key order");
+
+      let keys = Object.keys(storage);
+
+      is(keys.length, savedKeys.length);
+
+      for (let i = 0; i < keys.length; i++) {
+        is(keys[i], savedKeys[i], "Correct key");
+      }
+
+      info("Verifying values");
+
+      for (let item of items) {
+        is(storage.getItem(item.key), item.value, "Correct value");
+      }
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+
+      // 3rd snapshot
+
+      // Force key2 to load.
+      storage.getItem("key02");
+
+      // Fill out write infos a bit.
+      storage.removeItem("key05");
+      storage.setItem("key05", "value05");
+      storage.removeItem("key05");
+      storage.setItem("key11", "value11");
+      storage.setItem("key05", "value05");
+
+      items.push({ key: "key11", value: "value11" });
+
+      info("Verifying length");
+
+      is(storage.length, items.length, "Correct length");
+
+      // This forces to get all keys from the parent and then apply write infos
+      // on already cached values.
+      savedKeys = Object.keys(storage);
+
+      info("Verifying values");
+
+      for (let item of items) {
+        is(storage.getItem(item.key), item.value, "Correct value");
+      }
+
+      storage.removeItem("key11");
+
+      items.pop();
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+
+      // 4th snapshot
+
+      // Force loading of all items.
+      info("Verifying length");
+
+      is(storage.length, items.length, "Correct length");
+
+      info("Verifying values");
+
+      for (let item of items) {
+        is(storage.getItem(item.key), item.value, "Correct value");
+      }
+
+      is(storage.getItem("key11"), null, "Correct value");
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+
+      // 5th snapshot
+
+      // Force loading of all keys.
+      info("Saving key order");
+
+      savedKeys = Object.keys(storage);
+
+      // Force loading of all items.
+      info("Verifying length");
+
+      is(storage.length, items.length, "Correct length");
+
+      info("Verifying values");
+
+      for (let item of items) {
+        is(storage.getItem(item.key), item.value, "Correct value");
+      }
+
+      is(storage.getItem("key11"), null, "Correct value");
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+
+      // 6th snapshot
+      info("Verifying unknown item");
+
+      is(storage.getItem("key11"), null, "Correct value");
+
+      info("Verifying unknown item again");
+
+      is(storage.getItem("key11"), null, "Correct value");
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+
+      // 7th snapshot
+
+      // Save actual key order.
+      info("Saving key order");
+
+      savedKeys = Object.keys(storage);
+
+      await returnToEventLoop();
+
+      // 8th snapshot
+
+      // Force loading of all items, but in reverse order.
+      info("Getting values");
+
+      for (let i = items.length - 1; i >= 0; i--) {
+        let item = items[i];
+        storage.getItem(item.key);
+      }
+
+      info("Verifying key order");
+
+      keys = Object.keys(storage);
+
+      is(keys.length, savedKeys.length);
+
+      for (let i = 0; i < keys.length; i++) {
+        is(keys[i], savedKeys[i], "Correct key");
+      }
+
+      await returnToEventLoop();
+
+      // 9th snapshot
+
+      info("Clearing");
+
+      storage.clear();
+
+      info("Returning to event loop");
+
+      await returnToEventLoop();
+    }
+  }
+});
diff --git a/dom/localstorage/test/unit/test_stringLength.js b/dom/localstorage/test/unit/test_stringLength.js
new file mode 100644
index 0000000000..5d619b8e81
--- /dev/null
+++ b/dom/localstorage/test/unit/test_stringLength.js
@@ -0,0 +1,74 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const principal = getPrincipal("http://example.org");
+
+  const data = {};
+  data.key = "foobar";
+  data.secondKey = "foobaz";
+  data.value = {
+    length: 25637,
+  };
+  data.usage = data.key.length + data.value.length;
+
+  async function checkUsage(expectedUsage) {
+    info("Checking usage");
+
+    // This forces any pending changes to be flushed to disk.  It also forces
+    // data to be reloaded from disk at next localStorage API call.
+    request = resetOrigin(principal);
+    await requestFinished(request);
+
+    request = getOriginUsage(principal);
+    await requestFinished(request);
+
+    is(request.result.usage, expectedUsage, "Correct usage");
+  }
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Checking usage after profile installation");
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains storage.sqlite and webappsstore.sqlite.
+  installPackage("stringLength_profile");
+
+  await checkUsage(0);
+
+  info("Stage 2 - Checking usage after archived data migration");
+
+  info("Opening database");
+
+  let storage = getLocalStorage(principal);
+  storage.open();
+
+  await checkUsage(data.usage);
+
+  info("Stage 3 - Checking usage after copying the value");
+
+  info("Adding a second copy of the value");
+
+  let value = storage.getItem(data.key);
+  storage.setItem(data.secondKey, value);
+
+  await checkUsage(2 * data.usage);
+
+  info("Stage 4 - Checking length of the copied value");
+
+  value = storage.getItem(data.secondKey);
+  Assert.strictEqual(value.length, data.value.length, "Correct string length");
+});
diff --git a/dom/localstorage/test/unit/test_stringLength2.js b/dom/localstorage/test/unit/test_stringLength2.js
new file mode 100644
index 0000000000..868869a372
--- /dev/null
+++ b/dom/localstorage/test/unit/test_stringLength2.js
@@ -0,0 +1,79 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test is mainly to verify that string length is correctly computed for
+ * database values containing NULs. See bug 1541681.
+ */
+
+add_task(async function testSteps() {
+  const principal = getPrincipal("http://example.org");
+
+  const data = {};
+  data.key = "foobar";
+  data.secondKey = "foobaz";
+  data.value = {
+    length: 19253,
+  };
+  data.usage = data.key.length + data.value.length;
+
+  async function checkUsage(expectedUsage) {
+    info("Checking usage");
+
+    // This forces any pending changes to be flushed to disk.  It also forces
+    // data to be reloaded from disk at next localStorage API call.
+    request = resetOrigin(principal);
+    await requestFinished(request);
+
+    request = getOriginUsage(principal);
+    await requestFinished(request);
+
+    is(request.result.usage, expectedUsage, "Correct usage");
+  }
+
+  info("Setting pref");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Checking usage after profile installation");
+
+  info("Clearing");
+
+  let request = clear();
+  await requestFinished(request);
+
+  info("Installing package");
+
+  // The profile contains storage.sqlite and webappsstore.sqlite.
+  installPackage("stringLength2_profile");
+
+  await checkUsage(0);
+
+  info("Stage 2 - Checking usage after archived data migration");
+
+  info("Opening database");
+
+  let storage = getLocalStorage(principal);
+  storage.open();
+
+  await checkUsage(data.usage);
+
+  info("Stage 3 - Checking usage after copying the value");
+
+  info("Adding a second copy of the value");
+
+  let value = storage.getItem(data.key);
+  storage.setItem(data.secondKey, value);
+
+  await checkUsage(2 * data.usage);
+
+  info("Stage 4 - Checking length of the copied value");
+
+  value = storage.getItem(data.secondKey);
+  Assert.strictEqual(value.length, data.value.length, "Correct string length");
+});
diff --git a/dom/localstorage/test/unit/test_unicodeCharacters.js b/dom/localstorage/test/unit/test_unicodeCharacters.js
new file mode 100644
index 0000000000..3ea8923e0a
--- /dev/null
+++ b/dom/localstorage/test/unit/test_unicodeCharacters.js
@@ -0,0 +1,202 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+const interpretChar = (chars, index) => {
+  return chars.charCodeAt(index).toString(16).padStart(4, "0");
+};
+
+const hexEncode = str => {
+  let result = "";
+  const len = str.length;
+  for (let i = 0; i < len; ++i) {
+    result += interpretChar(str, i);
+  }
+  return result;
+};
+
+const collectCorrupted = (expected, actual) => {
+  const len = Math.min(expected.length, actual.length);
+  let notEquals = [];
+  for (let i = 0; i < len; ++i) {
+    if (expected[i] !== actual[i]) {
+      notEquals.push([hexEncode(expected[i]), hexEncode(actual[i])]);
+    }
+  }
+  return notEquals;
+};
+
+const sanitizeOutputWithSurrogates = (testValue, prefix = "") => {
+  let utf8What = prefix;
+  for (let i = 0; i < testValue.length; ++i) {
+    const valueChar = testValue.charCodeAt(i);
+    const isPlanar = 0xd800 <= valueChar && valueChar <= 0xdfff;
+    utf8What += isPlanar ? "\\u" + interpretChar(testValue, i) : testValue[i];
+  }
+  return utf8What;
+};
+
+const getEncodingSample = () => {
+  const expectedSample =
+    "3681207208613504e0a5028800b945551988c60050008027ebc2808c00d38e806e03d8210ac906722b85499be9d00000";
+
+  let result = "";
+  const len = expectedSample.length;
+  for (let i = 0; i < len; i += 4) {
+    result += String.fromCharCode(parseInt(expectedSample.slice(i, i + 4), 16));
+  }
+  return result;
+};
+
+const getSeparatedBasePlane = () => {
+  let result = "";
+  for (let i = 0xffff; i >= 0; --i) {
+    result += String.fromCharCode(i) + "\n";
+  }
+  return result;
+};
+
+const getJoinedBasePlane = () => {
+  let result = "";
+  for (let i = 0; i <= 0xffff; ++i) {
+    result += String.fromCharCode(i);
+  }
+  return result;
+};
+
+const getSurrogateCombinations = () => {
+  const upperLead = String.fromCharCode(0xdbff);
+  const lowerTrail = String.fromCharCode(0xdc00);
+
+  const regularSlot = ["w", "abcdefghijklmnopqrst", "aaaaaaaaaaaaaaaaaaaa", ""];
+  const surrogateSlot = [lowerTrail, upperLead];
+
+  let samples = [];
+  for (const leadSnippet of regularSlot) {
+    for (const firstSlot of surrogateSlot) {
+      for (const trailSnippet of regularSlot) {
+        for (const secondSlot of surrogateSlot) {
+          samples.push(leadSnippet + firstSlot + secondSlot + trailSnippet);
+        }
+        samples.push(leadSnippet + firstSlot + trailSnippet);
+      }
+    }
+  }
+
+  return samples;
+};
+
+const fetchFrom = async (itemKey, sample, meanwhile) => {
+  const principal = getPrincipal("http://example.com/", {});
+
+  let request = clearOrigin(principal);
+  await requestFinished(request);
+
+  const storage = getLocalStorage(principal);
+
+  await storage.setItem(itemKey, sample);
+
+  await meanwhile(principal);
+
+  return storage.getItem(itemKey);
+};
+
+/**
+ * Value fetched from existing snapshot based on
+ * existing in-memory datastore in the parent process
+ * without any communication between content/parent
+ */
+const fetchFromExistingSnapshotExistingDatastore = async (itemKey, sample) => {
+  return fetchFrom(itemKey, sample, async () => {});
+};
+
+/**
+ * Value fetched from newly created snapshot based on
+ * existing in-memory datastore in the parent process
+ */
+const fetchFromNewSnapshotExistingDatastore = async (itemKey, sample) => {
+  return fetchFrom(itemKey, sample, async () => {
+    await returnToEventLoop();
+  });
+};
+
+/**
+ * Value fetched from newly created snapshot based on newly created
+ * in-memory datastore based on database in the parent process
+ */
+const fetchFromNewSnapshotNewDatastore = async (itemKey, sample) => {
+  return fetchFrom(itemKey, sample, async principal => {
+    let request = resetOrigin(principal);
+    await requestFinished(request);
+  });
+};
+
+add_task(async function testSteps() {
+  /* This test is based on bug 1681300 */
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+  Services.prefs.setBoolPref("dom.storage.snapshot_reusing", false);
+
+  const reportWhat = (testKey, testValue) => {
+    if (testKey.length + testValue.length > 82) {
+      return testKey;
+    }
+    return sanitizeOutputWithSurrogates(testValue, /* prefix */ testKey + ":");
+  };
+
+  const testFetchMode = async (testType, storeAndLookup) => {
+    const testPairs = [
+      { testEmptyValue: [""] },
+      { testSampleKey: [getEncodingSample()] },
+      { testSeparatedKey: [getSeparatedBasePlane()] },
+      { testJoinedKey: [getJoinedBasePlane()] },
+      { testCombinations: getSurrogateCombinations() },
+    ];
+
+    for (const testPair of testPairs) {
+      for (const [testKey, expectedValues] of Object.entries(testPair)) {
+        for (const expected of expectedValues) {
+          const actual = await storeAndLookup(testKey, expected);
+          const testInfo = reportWhat(testKey, expected);
+          is(
+            null != actual,
+            true,
+            testType + ": Value not null for " + testInfo
+          );
+          is(
+            expected.length,
+            actual.length,
+            testType + ": Returned size for " + testInfo
+          );
+
+          const notEquals = collectCorrupted(expected, actual);
+          for (let i = 0; i < notEquals.length; ++i) {
+            is(
+              notEquals[i][0],
+              notEquals[i][1],
+              testType + ": Unequal character at " + i + " for " + testInfo
+            );
+          }
+        }
+      }
+    }
+  };
+
+  await testFetchMode(
+    "ExistingSnapshotExistingDatastore",
+    fetchFromExistingSnapshotExistingDatastore
+  );
+
+  await testFetchMode(
+    "NewSnapshotExistingDatastore",
+    fetchFromNewSnapshotExistingDatastore
+  );
+
+  await testFetchMode(
+    "NewSnapshotNewDatastore",
+    fetchFromNewSnapshotNewDatastore
+  );
+});
diff --git a/dom/localstorage/test/unit/test_uri_encoding_edge_cases.js b/dom/localstorage/test/unit/test_uri_encoding_edge_cases.js
new file mode 100644
index 0000000000..0da4e8584d
--- /dev/null
+++ b/dom/localstorage/test/unit/test_uri_encoding_edge_cases.js
@@ -0,0 +1,69 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * This test verifies that group and origin strings for URIs with special
+ * characters are consistent between calling
+ * EnsureQuotaForOringin/EnsureOriginIsInitailized and GetQuotaObject in
+ * PrepareDatastoreOp, so writing to local storage won't cause a crash because
+ * of a null quota object. See bug 1516333.
+ */
+
+add_task(async function testSteps() {
+  /**
+   * The edge cases are specified in this array of origins. Each edge case must
+   * contain two properties uri and path (origin directory path relative to the
+   * profile directory).
+   */
+  const origins = [
+    {
+      uri: "file:///test'.html",
+      path: "storage/default/file++++test'.html",
+    },
+    {
+      uri: "file:///test>.html",
+      path: "storage/default/file++++test%3E.html",
+    },
+  ];
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  for (let origin of origins) {
+    const principal = getPrincipal(origin.uri);
+
+    let originDir = getRelativeFile(origin.path);
+
+    info("Checking the origin directory existence");
+
+    ok(
+      !originDir.exists(),
+      `The origin directory ${origin.path} should not exists`
+    );
+
+    info("Getting storage");
+
+    let storage = getLocalStorage(principal);
+
+    info("Adding item");
+
+    storage.setItem("foo", "bar");
+
+    info("Resetting origin");
+
+    // This forces any pending changes to be flushed to disk (including origin
+    // directory creation).
+    let request = resetOrigin(principal);
+    await requestFinished(request);
+
+    info("Checking the origin directory existence");
+
+    ok(originDir.exists(), `The origin directory ${origin.path} should exist`);
+  }
+});
diff --git a/dom/localstorage/test/unit/test_usage.js b/dom/localstorage/test/unit/test_usage.js
new file mode 100644
index 0000000000..552a45e4a6
--- /dev/null
+++ b/dom/localstorage/test/unit/test_usage.js
@@ -0,0 +1,69 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const data = {};
+  data.key = "key1";
+  data.value = "value1";
+  data.usage = data.key.length + data.value.length;
+
+  const principal = getPrincipal("http://example.com");
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Testing usage after adding item");
+
+  info("Getting storage");
+
+  let storage = getLocalStorage(principal);
+
+  info("Adding item");
+
+  storage.setItem(data.key, data.value);
+
+  info("Resetting origin");
+
+  let request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, data.usage, "Correct usage");
+
+  info("Resetting");
+
+  request = reset();
+  await requestFinished(request);
+
+  info("Stage 2 - Testing usage after removing item");
+
+  info("Getting storage");
+
+  storage = getLocalStorage(principal);
+
+  info("Removing item");
+
+  storage.removeItem(data.key);
+
+  info("Resetting origin");
+
+  request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, 0, "Correct usage");
+});
diff --git a/dom/localstorage/test/unit/test_usageAfterMigration.js b/dom/localstorage/test/unit/test_usageAfterMigration.js
new file mode 100644
index 0000000000..a0bd5efd5b
--- /dev/null
+++ b/dom/localstorage/test/unit/test_usageAfterMigration.js
@@ -0,0 +1,164 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const principal = getPrincipal("http://example.com");
+
+  const dataFile = getRelativeFile(
+    "storage/default/http+++example.com/ls/data.sqlite"
+  );
+
+  const usageJournalFile = getRelativeFile(
+    "storage/default/http+++example.com/ls/usage-journal"
+  );
+
+  const usageFile = getRelativeFile(
+    "storage/default/http+++example.com/ls/usage"
+  );
+
+  const data = {};
+  data.key = "foo";
+  data.value = "bar";
+  data.usage = data.key.length + data.value.length;
+
+  async function createStorageForMigration(createUsageDir) {
+    info("Clearing");
+
+    let request = clear();
+    await requestFinished(request);
+
+    info("Installing package");
+
+    // The profile contains storage.sqlite and webappsstore.sqlite. The file
+    // create_db.js in the package was run locally, specifically it was
+    // temporarily added to xpcshell.ini and then executed:
+    // mach xpcshell-test --interactive dom/localstorage/test/unit/create_db.js
+    installPackage("usageAfterMigration_profile");
+
+    if (createUsageDir) {
+      // Origin must be initialized before the usage dir is created.
+
+      info("Initializing storage");
+
+      request = initStorage();
+      await requestFinished(request);
+
+      info("Initializing temporary storage");
+
+      request = initTemporaryStorage();
+      await requestFinished(request);
+
+      info("Initializing origin");
+
+      request = initTemporaryOrigin("default", principal);
+      await requestFinished(request);
+
+      info("Creating usage as a directory");
+
+      // This will cause a failure during migration.
+      usageFile.create(Ci.nsIFile.DIRECTORY_TYPE, parseInt("0755", 8));
+    }
+  }
+
+  function verifyData() {
+    ok(dataFile.exists(), "Data file does exist");
+  }
+
+  async function verifyUsage(success) {
+    info("Verifying usage in memory");
+
+    let request = getOriginUsage(principal, /* fromMemory */ true);
+    await requestFinished(request);
+
+    if (success) {
+      is(request.result.usage, data.usage, "Correct usage");
+    } else {
+      is(request.result.usage, 0, "Zero usage");
+    }
+
+    info("Verifying usage on disk");
+
+    if (success) {
+      ok(!usageJournalFile.exists(), "Usage journal file doesn't exist");
+      ok(usageFile.exists(), "Usage file does exist");
+      let usage = await readUsageFromUsageFile(usageFile);
+      is(usage, data.usage, "Correct usage");
+    } else {
+      ok(usageJournalFile.exists(), "Usage journal file does exist");
+      ok(usageFile.exists(), "Usage file does exist");
+    }
+  }
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Testing usage after successful data migration");
+
+  await createStorageForMigration(/* createUsageDir */ false);
+
+  info("Getting storage");
+
+  let storage = getLocalStorage(principal);
+
+  info("Opening");
+
+  storage.open();
+
+  verifyData();
+
+  await verifyUsage(/* success */ true);
+
+  info("Stage 2 - Testing usage after unsuccessful data migration");
+
+  await createStorageForMigration(/* createUsageDir */ true);
+
+  info("Getting storage");
+
+  storage = getLocalStorage(principal);
+
+  info("Opening");
+
+  try {
+    storage.open();
+    ok(false, "Should have thrown");
+  } catch (ex) {
+    ok(true, "Did throw");
+  }
+
+  verifyData();
+
+  await verifyUsage(/* success */ false);
+
+  info("Stage 3 - Testing usage after unsuccessful/successful data migration");
+
+  await createStorageForMigration(/* createUsageDir */ true);
+
+  info("Getting storage");
+
+  storage = getLocalStorage(principal);
+
+  info("Opening");
+
+  try {
+    storage.open();
+    ok(false, "Should have thrown");
+  } catch (ex) {
+    ok(true, "Did throw");
+  }
+
+  usageFile.remove(true);
+
+  info("Opening");
+
+  storage.open();
+
+  verifyData();
+
+  await verifyUsage(/* success */ true);
+});
diff --git a/dom/localstorage/test/unit/usageAfterMigration_profile.zip b/dom/localstorage/test/unit/usageAfterMigration_profile.zip
new file mode 100644
index 0000000000..30a73292c3
--- /dev/null
+++ b/dom/localstorage/test/unit/usageAfterMigration_profile.zip
diff --git a/dom/localstorage/test/unit/xpcshell.toml b/dom/localstorage/test/unit/xpcshell.toml
new file mode 100644
index 0000000000..9c13f3ed8f
--- /dev/null
+++ b/dom/localstorage/test/unit/xpcshell.toml
@@ -0,0 +1,97 @@
+[DEFAULT]
+head = "head.js"
+tags = "condprof"
+support-files = [
+  "archive_profile.zip",
+  "corruptedDatabase_profile.zip",
+  "corruptedDatabase_missingUsageFile_profile.zip",
+  "groupMismatch_profile.zip",
+  "migration_profile.zip",
+  "schema3upgrade_profile.zip",
+  "schema4upgrade_profile.zip",
+  "stringLength2_profile.zip",
+  "stringLength_profile.zip",
+  "usageAfterMigration_profile.zip",
+]
+
+["make_migration_emptyValue.js"]
+skip-if = ["true"] # Only used for recreating migration_emptyValue_profile.zip
+
+["test_archive.js"]
+
+["test_clientValidation.js"]
+
+["test_corruptedDatabase.js"]
+
+["test_databaseShadowing1.js"]
+prefs = ["dom.storage.shadow_writes=true"]
+run-sequentially = "test_databaseShadowing2.js depends on a file produced by this test"
+
+["test_databaseShadowing2.js"]
+run-sequentially = "this test depends on a file produced by test_databaseShadowing1.js"
+
+["test_databaseShadowing_clearOrigin1.js"]
+prefs = ["dom.storage.shadow_writes=true"]
+run-sequentially = "test_databaseShadowing_clearOrigin2.js depends on a file produced by this test"
+
+["test_databaseShadowing_clearOrigin2.js"]
+run-sequentially = "this test depends on a file produced by test_databaseShadowing_clearOrigin1.js"
+
+["test_databaseShadowing_clearOriginsByPattern1.js"]
+prefs = ["dom.storage.shadow_writes=true"]
+run-sequentially = "test_databaseShadowing_clearOriginsByPattern2.js depends on a file produced by this test"
+
+["test_databaseShadowing_clearOriginsByPattern2.js"]
+run-sequentially = "this test depends on a file produced by test_databaseShadowing_clearOriginsByPattern1.js"
+
+["test_databaseShadowing_clearOriginsByPrefix1.js"]
+prefs = ["dom.storage.shadow_writes=true"]
+run-sequentially = "test_databaseShadowing_clearOriginsByPrefix2.js depends on a file produced by this test"
+
+["test_databaseShadowing_clearOriginsByPrefix2.js"]
+run-sequentially = "this test depends on a file produced by test_databaseShadowing_clearOriginsByPrefix1.js"
+
+["test_eviction.js"]
+
+["test_flushing.js"]
+
+["test_groupLimit.js"]
+
+["test_groupMismatch.js"]
+
+["test_largeItems.js"]
+
+["test_lsng_enabled.js"]
+
+["test_migration.js"]
+
+["test_migration_emptyValue.js"]
+support-files = ["migration_emptyValue_profile.zip",]
+
+["test_old_lsng_pref.js"]
+
+["test_orderingAfterRemoveAdd.js"]
+
+["test_originInit.js"]
+
+["test_preloading.js"]
+
+["test_schema3upgrade.js"]
+
+["test_schema4upgrade.js"]
+
+["test_snapshotting.js"]
+skip-if = ["tsan"] # Unreasonably slow, bug 1612707
+requesttimeoutfactor = 4
+
+["test_stringLength.js"]
+
+["test_stringLength2.js"]
+
+["test_unicodeCharacters.js"]
+
+["test_uri_encoding_edge_cases.js"]
+
+["test_usage.js"]
+
+["test_usageAfterMigration.js"]