10 files changed, 882 insertions, 0 deletions
diff --git a/dom/fs/test/common/.eslintrc.js b/dom/fs/test/common/.eslintrc.js
new file mode 100644
index 0000000000..d805cf6e0f
--- /dev/null
+++ b/dom/fs/test/common/.eslintrc.js
@@ -0,0 +1,14 @@
+/* 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/. */
+
+"use strict";
+
+module.exports = {
+  globals: {
+    Assert: true,
+    exported_symbols: true,
+    require_module: true,
+    Utils: true,
+  },
+};
diff --git a/dom/fs/test/common/dummy.js b/dom/fs/test/common/dummy.js
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/dom/fs/test/common/dummy.js
diff --git a/dom/fs/test/common/mochitest.ini b/dom/fs/test/common/mochitest.ini
new file mode 100644
index 0000000000..4926b81a48
--- /dev/null
+++ b/dom/fs/test/common/mochitest.ini
@@ -0,0 +1,14 @@
+# 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 =
+  nsresult.js
+  test_basics.js
+  test_fileSystemDirectoryHandle.js
+  test_syncAccessHandle.js
+  test_writableFileStream.js
+
+[dummy.js]
+skip-if = true
diff --git a/dom/fs/test/common/moz.build b/dom/fs/test/common/moz.build
new file mode 100644
index 0000000000..c8636196fc
--- /dev/null
+++ b/dom/fs/test/common/moz.build
@@ -0,0 +1,21 @@
+# -*- 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/.
+
+MOCHITEST_MANIFESTS += [
+    "mochitest.ini",
+]
+
+XPCSHELL_TESTS_MANIFESTS += [
+    "xpcshell.ini",
+]
+
+TESTING_JS_MODULES.dom.fs.test.common += [
+    "nsresult.js",
+    "test_basics.js",
+    "test_fileSystemDirectoryHandle.js",
+    "test_syncAccessHandle.js",
+    "test_writableFileStream.js",
+]
diff --git a/dom/fs/test/common/nsresult.js b/dom/fs/test/common/nsresult.js
new file mode 100644
index 0000000000..6e59b947a1
--- /dev/null
+++ b/dom/fs/test/common/nsresult.js
@@ -0,0 +1,9 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+const nsresult = {
+  NS_ERROR_NOT_IMPLEMENTED: Cr.NS_ERROR_NOT_IMPLEMENTED,
+};
+exported_symbols.nsresult = nsresult;
diff --git a/dom/fs/test/common/test_basics.js b/dom/fs/test/common/test_basics.js
new file mode 100644
index 0000000000..a040112356
--- /dev/null
+++ b/dom/fs/test/common/test_basics.js
@@ -0,0 +1,301 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+// This test must be first, since we need the actor not to be created already.
+exported_symbols.testGetDirectoryTwice = async function () {
+  const promise1 = navigator.storage.getDirectory();
+  const promise2 = navigator.storage.getDirectory();
+
+  await Promise.all([promise1, promise2]);
+
+  Assert.ok(true, "Should not have thrown");
+};
+
+exported_symbols.testGetDirectoryDoesNotThrow = async function () {
+  await navigator.storage.getDirectory();
+
+  Assert.ok(true, "Should not have thrown");
+};
+
+exported_symbols.testGetDirectoryKindIsDirectory = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  Assert.equal(root.kind, "directory");
+};
+
+exported_symbols.testDirectoryHandleStringConversion = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  Assert.equal(
+    "" + root,
+    "[object FileSystemDirectoryHandle]",
+    "Is directoryHandle convertible to string?"
+  );
+};
+
+exported_symbols.testNewDirectoryHandleFromPrototype = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  try {
+    Object.create(root.prototype);
+    Assert.ok(false, "Should have thrown");
+  } catch (ex) {
+    Assert.ok(true, "Should have thrown");
+    Assert.ok(ex instanceof TypeError, "Threw the right error type");
+  }
+};
+
+exported_symbols.testIsSameEntryRoot = async function () {
+  const root = await navigator.storage.getDirectory();
+  try {
+    await root.move(root);
+    Assert.ok(false, "root should not be movable");
+  } catch (ex) {
+    Assert.ok(true, "root isn't movable");
+  }
+};
+
+exported_symbols.testDirectoryHandleSupportsKeysIterator = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  const it = await root.keys();
+  Assert.ok(!!it, "Does root support keys iterator?");
+};
+
+exported_symbols.testKeysIteratorNextIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  const it = await root.keys();
+  Assert.ok(!!it, "Does root support keys iterator?");
+
+  const item = await it.next();
+  Assert.ok(!!item, "Should return an item");
+};
+
+exported_symbols.testDirectoryHandleSupportsValuesIterator = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  const it = await root.values();
+  Assert.ok(!!it, "Does root support values iterator?");
+};
+
+exported_symbols.testValuesIteratorNextIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  const it = await root.values();
+  Assert.ok(!!it, "Does root support values iterator?");
+
+  const item = await it.next();
+  Assert.ok(!!item, "Should return an item");
+};
+
+exported_symbols.testDirectoryHandleSupportsEntriesIterator =
+  async function () {
+    const root = await navigator.storage.getDirectory();
+
+    const it = await root.entries();
+    Assert.ok(!!it, "Does root support entries iterator?");
+  };
+
+exported_symbols.testEntriesIteratorNextIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  const it = await root.entries();
+  Assert.ok(!!it, "Does root support entries iterator?");
+
+  const item = await it.next();
+  Assert.ok(!!item, "Should return an item");
+};
+
+exported_symbols.testGetFileHandleIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+  const allowCreate = { create: true };
+
+  const item = await root.getFileHandle("fileName", allowCreate);
+  Assert.ok(!!item, "Should return an item");
+};
+
+exported_symbols.testGetDirectoryHandleIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+  const allowCreate = { create: true };
+
+  const item = await root.getDirectoryHandle("dirName", allowCreate);
+  Assert.ok(!!item, "Should return an item");
+};
+
+exported_symbols.testRemoveEntryIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+  const removeOptions = { recursive: true };
+
+  await root.removeEntry("fileName", removeOptions);
+  await root.removeEntry("dirName", removeOptions);
+  try {
+    await root.removeEntry("doesNotExist", removeOptions);
+    Assert.ok(false, "Should have thrown");
+  } catch (ex) {
+    Assert.ok(true, "Should have thrown");
+    Assert.equal(
+      ex.message,
+      "Entry not found",
+      "Threw the right error message"
+    );
+  }
+};
+
+exported_symbols.testResolveIsCallable = async function () {
+  const root = await navigator.storage.getDirectory();
+  const allowCreate = { create: true };
+  const item = await root.getFileHandle("fileName", allowCreate);
+
+  let path = await root.resolve(item);
+  Assert.equal(path.length, 1);
+  Assert.equal(path[0], "fileName", "Resolve got the right path");
+};
+
+exported_symbols.testFileType = async function () {
+  const root = await navigator.storage.getDirectory();
+  const allowCreate = { create: true };
+  const nameStem = "testFileType";
+  const empty = "";
+
+  const extensions = [
+    "txt",
+    "jS",
+    "JSON",
+    "css",
+    "html",
+    "htm",
+    "xhtml",
+    "xml",
+    "xhtml+xml",
+    "png",
+    "apng",
+    "jPg",
+    "Jpeg",
+    "pdF",
+    "out",
+    "sh",
+    "ExE",
+    "psid",
+    "EXE ",
+    " EXE",
+    "EX\uff65",
+    "\udbff\udbff\udbff",
+    "\udc00\udc00\udc00",
+    "js\udbff",
+    "\udc00js",
+    "???",
+    "\root",
+    empty,
+    "AXS",
+    "dll",
+    "ocx",
+    "1",
+    "ps1",
+    "cmd",
+    "xpi",
+    "swf",
+  ];
+
+  const expectedTypes = [
+    "text/plain",
+    "application/javascript",
+    "application/json",
+    "text/css",
+    "text/html",
+    "text/html",
+    "application/xhtml+xml",
+    "text/xml",
+    empty,
+    "image/png",
+    "image/apng",
+    "image/jpeg",
+    "image/jpeg",
+    "application/pdf",
+    empty,
+    "application/x-sh",
+    "application/octet-stream",
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    empty,
+    "application/olescript",
+    "application/x-msdownload",
+    "application/octet-stream",
+    empty,
+    empty,
+    "text/plain",
+    "application/x-xpinstall",
+    "application/x-shockwave-flash",
+  ];
+
+  Assert.equal(extensions.length, expectedTypes.length);
+
+  await Promise.all(
+    extensions.map(async (ext, i) => {
+      const fileName = nameStem + "." + ext;
+      const fileHandle = await root.getFileHandle(fileName, allowCreate);
+      const fileObject = await fileHandle.getFile();
+      Assert.equal(fileObject.name, fileHandle.name);
+      Assert.equal(fileObject.type, expectedTypes[i]);
+    })
+  );
+};
+
+exported_symbols.testContentTypeChangesOnMove = async function () {
+  const allowCreate = { create: true };
+  const root = await navigator.storage.getDirectory();
+  const oldName = "testFile.txt";
+  const oldType = "text/plain";
+  const subdir = await root.getDirectoryHandle("subdir", allowCreate);
+
+  const testName = "testFile.json";
+  const testType = "application/json";
+
+  const fileHandle = await root.getFileHandle(oldName, allowCreate);
+
+  async function checkMove(newName, newType) {
+    Assert.equal(fileHandle.name, newName, "Has filename changed?");
+    {
+      const fileObject = await fileHandle.getFile();
+      Assert.equal(fileObject.name, newName, "Is the fileobject renamed?");
+      Assert.equal(fileObject.type, newType, "Is the fileobject type updated?");
+    }
+  }
+
+  // No name change
+  await checkMove(oldName, oldType);
+  await fileHandle.move(subdir);
+  await checkMove(oldName, oldType);
+  await fileHandle.move(root, oldName);
+  await checkMove(oldName, oldType);
+
+  // With name change
+
+  async function testMoveCall(...combo) {
+    await fileHandle.move(...combo);
+    await checkMove(testName, testType);
+    await fileHandle.move(root, oldName);
+    await checkMove(oldName, oldType);
+  }
+
+  await testMoveCall(subdir, testName);
+  await testMoveCall(root, testName);
+  await testMoveCall(testName);
+};
+
+for (const [key, value] of Object.entries(exported_symbols)) {
+  Object.defineProperty(value, "name", {
+    value: key,
+    writable: false,
+  });
+}
diff --git a/dom/fs/test/common/test_fileSystemDirectoryHandle.js b/dom/fs/test/common/test_fileSystemDirectoryHandle.js
new file mode 100644
index 0000000000..65a293cd28
--- /dev/null
+++ b/dom/fs/test/common/test_fileSystemDirectoryHandle.js
@@ -0,0 +1,180 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+exported_symbols.smokeTest = async function smokeTest() {
+  const storage = navigator.storage;
+  const subdirectoryNames = new Set(["Documents", "Downloads", "Music"]);
+  const allowCreate = { create: true };
+
+  {
+    let root = await storage.getDirectory();
+    Assert.ok(root, "Can we access the root directory?");
+
+    let it = await root.values();
+    Assert.ok(!!it, "Does root have values iterator?");
+
+    let elem = await it.next();
+    Assert.ok(elem.done, "Is root directory empty?");
+
+    for (let dirName of subdirectoryNames) {
+      await root.getDirectoryHandle(dirName, allowCreate);
+      Assert.ok(true, "Was it possible to add subdirectory " + dirName + "?");
+    }
+  }
+
+  {
+    let root = await storage.getDirectory();
+    Assert.ok(root, "Can we refresh the root directory?");
+
+    let it = await root.values();
+    Assert.ok(!!it, "Does root have values iterator?");
+
+    let hasElements = false;
+    let hangGuard = 0;
+    for await (let [key, elem] of root.entries()) {
+      Assert.ok(elem, "Is element not non-empty?");
+      Assert.equal("directory", elem.kind, "Is found item a directory?");
+      Assert.ok(
+        elem.name.length >= 1 && elem.name.match("^[A-Za-z]{1,64}"),
+        "Are names of the elements strings?"
+      );
+      Assert.equal(key, elem.name);
+      Assert.ok(subdirectoryNames.has(elem.name), "Is name among known names?");
+      hasElements = true;
+      ++hangGuard;
+      if (hangGuard == 10) {
+        break; // Exit if there is a hang
+      }
+    }
+
+    Assert.ok(hasElements, "Is values container now non-empty?");
+    Assert.equal(3, hangGuard, "Do we only have three elements?");
+
+    {
+      it = await root.values();
+      Assert.ok(!!it, "Does root have values iterator?");
+      let elem = await it.next();
+
+      await elem.value.getDirectoryHandle("Trash", allowCreate);
+      let subit = elem.value.values();
+      Assert.ok(!!elem, "Is element not non-empty?");
+      let subdirResult = await subit.next();
+      let subdir = subdirResult.value;
+      Assert.ok(!!subdir, "Is element not non-empty?");
+      Assert.equal("directory", subdir.kind, "Is found item a directory?");
+      Assert.equal("Trash", subdir.name, "Is found item a directory?");
+    }
+
+    const wipeEverything = { recursive: true };
+    for (let dirName of subdirectoryNames) {
+      await root.removeEntry(dirName, wipeEverything);
+      Assert.ok(
+        true,
+        "Was it possible to remove subdirectory " + dirName + "?"
+      );
+    }
+  }
+
+  {
+    let root = await storage.getDirectory();
+    Assert.ok(root, "Can we refresh the root directory?");
+
+    let it = root.values();
+    Assert.ok(!!it, "Does root have values iterator?");
+
+    let elem = await it.next();
+    Assert.ok(elem.done, "Is root directory empty?");
+  }
+};
+
+exported_symbols.quotaTest = async function () {
+  const storage = navigator.storage;
+  const allowCreate = { create: true };
+
+  {
+    let root = await storage.getDirectory();
+    Assert.ok(root, "Can we access the root directory?");
+
+    const fileHandle = await root.getFileHandle("test.txt", allowCreate);
+    Assert.ok(!!fileHandle, "Can we get file handle?");
+
+    const cachedOriginUsage = await Utils.getCachedOriginUsage();
+
+    const writable = await fileHandle.createWritable();
+    Assert.ok(!!writable, "Can we create writable file stream?");
+
+    const buffer = new ArrayBuffer(42);
+    Assert.ok(!!buffer, "Can we create array buffer?");
+
+    const result = await writable.write(buffer);
+    Assert.equal(result, undefined, "Can we write entire buffer?");
+
+    await writable.close();
+
+    const cachedOriginUsage2 = await Utils.getCachedOriginUsage();
+
+    Assert.equal(
+      cachedOriginUsage2 - cachedOriginUsage,
+      buffer.byteLength,
+      "Is cached origin usage correct after writing?"
+    );
+
+    await root.removeEntry("test.txt");
+
+    const cachedOriginUsage3 = await Utils.getCachedOriginUsage();
+
+    Assert.equal(
+      cachedOriginUsage3,
+      cachedOriginUsage,
+      "Is cached origin usage correct after removing file?"
+    );
+  }
+};
+
+exported_symbols.pagedIterationTest = async function () {
+  const root = await navigator.storage.getDirectory();
+
+  for await (let contentItem of root.keys()) {
+    await root.removeEntry(contentItem, { recursive: true });
+  }
+
+  const allowCreate = { create: true };
+
+  // When half of the buffer is iterated, a request for the second half is sent.
+  // We test that the this boundary is crossed smoothly.
+  // After the buffer is filled, a request for more items is sent. The
+  // items are placed in the first half of the buffer.
+  // This boundary should also be crossed without problems.
+  // Currently, the buffer is half-filled at 1024.
+  const itemBatch = 3 + 2 * 1024;
+  for (let i = 0; i <= itemBatch; ++i) {
+    await root.getDirectoryHandle("" + i, allowCreate);
+  }
+
+  let result = 0;
+  let sum = 0;
+  const handles = new Set();
+  let isUnique = true;
+  for await (let [key, elem] of root.entries()) {
+    result += key.length;
+    sum += parseInt(elem.name);
+    if (handles.has(key)) {
+      // Asserting here is slow and verbose
+      isUnique = false;
+      break;
+    }
+    handles.add(key);
+  }
+  Assert.ok(isUnique);
+  Assert.equal(result, 7098);
+  Assert.equal(sum, (itemBatch * (itemBatch + 1)) / 2);
+};
+
+for (const [key, value] of Object.entries(exported_symbols)) {
+  Object.defineProperty(value, "name", {
+    value: key,
+    writable: false,
+  });
+}
diff --git a/dom/fs/test/common/test_syncAccessHandle.js b/dom/fs/test/common/test_syncAccessHandle.js
new file mode 100644
index 0000000000..aaea95b20d
--- /dev/null
+++ b/dom/fs/test/common/test_syncAccessHandle.js
@@ -0,0 +1,237 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const allowCreate = { create: true };
+
+exported_symbols.test0 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  try {
+    await root.getFileHandle("test.txt");
+    Assert.ok(false, "Opened file that shouldn't exist");
+  } catch (e) {
+    dump("caught exception when we tried to open a non-existant file\n");
+  }
+};
+
+exported_symbols.test1 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt", allowCreate);
+  Assert.ok(!!testFile, "Can't create file");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle");
+  await handle.close();
+  handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create second SyncAccessHandle to same file");
+  await handle.close();
+};
+
+exported_symbols.test2 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt");
+  Assert.ok(!!testFile, "Can't open file");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle");
+  await handle.close();
+
+  await root.removeEntry("test.txt");
+  try {
+    handle = await testFile.createSyncAccessHandle();
+    Assert.ok(!!handle, "Didn't remove file!");
+    if (handle) {
+      await handle.close();
+    }
+  } catch (e) {
+    dump("Caught exception trying to create accesshandle to deleted file\n");
+  }
+};
+
+exported_symbols.test3 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(!!root, "Can we access the root directory?");
+
+  let dir = await root.getDirectoryHandle("dir", allowCreate);
+  Assert.ok(!!dir, "Can we create a directory?");
+
+  // XXX not implemented yet
+  //const path = await root.resolve(dir);
+  //Assert.ok(path == ["dir"], "Wrong path: " + path);
+
+  let dir2 = await dir.getDirectoryHandle("dir", allowCreate);
+  Assert.ok(!!dir, "Can we create dir/dir?");
+
+  // XXX not implemented yet
+  //const path = await root.resolve(dir2);
+  //Assert.ok(path == ["dir", "dir"], "Wrong path: " + path);
+
+  let dir3 = await dir.getDirectoryHandle("bar", allowCreate);
+  Assert.ok(!!dir3, "Can we create dir/bar?");
+
+  // This should fail
+  try {
+    await root.getDirectoryHandle("bar");
+    Assert.ok(!dir, "we shouldn't be able to get bar unless we create it");
+  } catch (e) {
+    dump("caught exception when we tried to get a non-existant dir\n");
+  }
+
+  const testFile = await dir2.getFileHandle("test.txt", allowCreate);
+  Assert.ok(!!testFile, "Can't create file in dir2");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle in dir2");
+  await handle.close();
+};
+
+exported_symbols.test4 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(!!root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt", allowCreate);
+  Assert.ok(!!testFile, "Can't access existing file");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle to existing file");
+
+  // Write a sentence to the end of the file.
+  const encoder = new TextEncoder();
+  const writeBuffer = encoder.encode("Thank you for reading this.");
+  const writeSize = handle.write(writeBuffer);
+  Assert.ok(!!writeSize);
+
+  // Read it back
+  // Get size of the file.
+  let fileSize = await handle.getSize();
+  Assert.ok(fileSize == writeBuffer.byteLength);
+  // Read file content to a buffer.
+  const readBuffer = new ArrayBuffer(fileSize);
+  const readSize = handle.read(readBuffer, { at: 0 });
+  Assert.ok(!!readSize);
+  //Assert.ok(readBuffer == writeBuffer);
+
+  await handle.truncate(5);
+  fileSize = await handle.getSize();
+  Assert.ok(fileSize == 5);
+
+  await handle.flush();
+  await handle.close();
+};
+
+exported_symbols.test5 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(!!root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt");
+  Assert.ok(!!testFile, "Can't create file");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle");
+
+  try {
+    const testFile2 = await root.getFileHandle("test2.txt", allowCreate);
+    let handle2 = await testFile2.createSyncAccessHandle();
+    Assert.ok(!!handle2, "can't create SyncAccessHandle to second file!");
+    if (handle2) {
+      await handle2.close();
+    }
+  } catch (e) {
+    Assert.ok(false, "Failed to create second file");
+  }
+
+  await handle.close();
+};
+
+exported_symbols.test6 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt");
+  Assert.ok(!!testFile, "Can't get file");
+  let handle = await testFile.createSyncAccessHandle();
+  Assert.ok(!!handle, "Can't create SyncAccessHandle");
+
+  try {
+    let handle2 = await testFile.createSyncAccessHandle();
+    Assert.ok(!handle2, "Shouldn't create SyncAccessHandle!");
+    if (handle2) {
+      await handle2.close();
+    }
+  } catch (e) {
+    // should always happen
+    dump("caught exception when we tried to get 2 SyncAccessHandles\n");
+  }
+
+  // test that locks work across multiple connections for an origin
+  try {
+    let root2 = await navigator.storage.getDirectory();
+    Assert.ok(root2, "Can we access the root2 directory?");
+
+    const testFile2 = await root2.getFileHandle("test.txt");
+    Assert.ok(!!testFile2, "Can't get file");
+    let handle2 = await testFile2.createSyncAccessHandle();
+    Assert.ok(!handle2, "Shouldn't create SyncAccessHandle (2)!");
+    if (handle2) {
+      await handle2.close();
+    }
+  } catch (e) {
+    // should always happen
+    dump("caught exception when we tried to get 2 SyncAccessHandles\n");
+  }
+
+  if (handle) {
+    await handle.close();
+  }
+};
+
+exported_symbols.quotaTest = async function () {
+  const shrinkedStorageSizeKB = 5 * 1024;
+  const defaultDatabaseSize = 294912;
+
+  // Shrink storage size to 5MB.
+  await Utils.shrinkStorageSize(shrinkedStorageSizeKB);
+
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  // Fill entire storage.
+  const fileHandle = await root.getFileHandle("test.txt");
+  Assert.ok(!!fileHandle, "Can we get file handle?");
+
+  const accessHandle = await fileHandle.createSyncAccessHandle();
+  Assert.ok(!!accessHandle, "Can we create sync access handle?");
+
+  const buffer = new ArrayBuffer(
+    shrinkedStorageSizeKB * 1024 - defaultDatabaseSize
+  );
+  Assert.ok(!!buffer, "Can we create array buffer?");
+
+  const written = accessHandle.write(buffer);
+  Assert.equal(written, buffer.byteLength, "Can we write entire buffer?");
+
+  // Try to write one more byte.
+  const fileHandle2 = await root.getFileHandle("test2.txt");
+  Assert.ok(!!fileHandle2, "Can we get file handle?");
+
+  const accessHandle2 = await fileHandle2.createSyncAccessHandle();
+  Assert.ok(!!accessHandle2, "Can we create sync access handle?");
+
+  const buffer2 = new ArrayBuffer(1);
+  Assert.ok(!!buffer2, "Can we create array buffer?");
+
+  const written2 = accessHandle2.write(buffer2);
+  Assert.equal(written2, 0, "Can we write beyond the limit?");
+
+  await accessHandle.close();
+  await accessHandle2.close();
+
+  await Utils.restoreStorageSize();
+};
+
+for (const [key, value] of Object.entries(exported_symbols)) {
+  Object.defineProperty(value, "name", {
+    value: key,
+    writable: false,
+  });
+}
diff --git a/dom/fs/test/common/test_writableFileStream.js b/dom/fs/test/common/test_writableFileStream.js
new file mode 100644
index 0000000000..20226ff061
--- /dev/null
+++ b/dom/fs/test/common/test_writableFileStream.js
@@ -0,0 +1,93 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+const allowCreate = { create: true };
+
+exported_symbols.test0 = async function () {
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(!!root, "Can we access the root directory?");
+
+  const testFile = await root.getFileHandle("test.txt", allowCreate);
+  Assert.ok(!!testFile, "Can't access existing file");
+  let writable = await testFile.createWritable();
+  Assert.ok(!!writable, "Can't create WritableFileStream to existing file");
+
+  // Write a sentence to the end of the file.
+  const encoder = new TextEncoder();
+  const writeBuffer = encoder.encode("Thank you for reading this.");
+  try {
+    dump("Trying to write...\n");
+    await writable.write(writeBuffer);
+    dump("closing...\n");
+    await writable.close();
+  } catch (e) {
+    Assert.ok(false, "Couldn't write to WritableFileStream: " + e);
+  }
+
+  // Read it back
+  // Get size of the file.
+  let file = await testFile.getFile();
+  Assert.ok(
+    !!file,
+    "Can't create File to file written with WritableFileStream"
+  );
+  let fileSize = file.size;
+  Assert.ok(fileSize == writeBuffer.byteLength);
+};
+
+exported_symbols.quotaTest = async function () {
+  const shrinkedStorageSizeKB = 5 * 1024;
+  const defaultDatabaseSize = 294912;
+
+  // Shrink storage size to 5MB.
+  await Utils.shrinkStorageSize(shrinkedStorageSizeKB);
+
+  let root = await navigator.storage.getDirectory();
+  Assert.ok(root, "Can we access the root directory?");
+
+  // Fill entire storage.
+  const fileHandle = await root.getFileHandle("test.txt", allowCreate);
+  Assert.ok(!!fileHandle, "Can we get file handle?");
+
+  const writable = await fileHandle.createWritable();
+  Assert.ok(!!writable, "Can we create writable file stream?");
+
+  const buffer = new ArrayBuffer(
+    shrinkedStorageSizeKB * 1024 - defaultDatabaseSize
+  );
+  Assert.ok(!!buffer, "Can we create array buffer?");
+
+  const result = await writable.write(buffer);
+  Assert.equal(result, undefined, "Can we write entire buffer?");
+
+  // Try to write one more byte.
+  const fileHandle2 = await root.getFileHandle("test2.txt", allowCreate);
+  Assert.ok(!!fileHandle2, "Can we get file handle?");
+
+  const writable2 = await fileHandle2.createWritable();
+  Assert.ok(!!writable2, "Can we create writable file stream?");
+
+  const buffer2 = new ArrayBuffer(1);
+  Assert.ok(!!buffer2, "Can we create array buffer?");
+
+  try {
+    await writable2.write(buffer2);
+    Assert.ok(false, "Should have thrown");
+  } catch (ex) {
+    Assert.ok(true, "Did throw");
+    Assert.ok(DOMException.isInstance(ex), "Threw DOMException");
+    Assert.equal(ex.name, "QuotaExceededError", "Threw right DOMException");
+  }
+
+  await writable.close();
+  // writable2 is already closed because of the failed write above
+
+  await Utils.restoreStorageSize();
+};
+
+for (const [key, value] of Object.entries(exported_symbols)) {
+  Object.defineProperty(value, "name", {
+    value: key,
+    writable: false,
+  });
+}
diff --git a/dom/fs/test/common/xpcshell.ini b/dom/fs/test/common/xpcshell.ini
new file mode 100644
index 0000000000..b63970a370
--- /dev/null
+++ b/dom/fs/test/common/xpcshell.ini
@@ -0,0 +1,13 @@
+# 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 =
+  nsresult.js
+  test_basics.js
+  test_fileSystemDirectoryHandle.js
+  test_writableFileStream.js
+
+[dummy.js]
+skip-if = true